Comparison of Hasselblad photos / lens quality with XCD lenses versus Zeiss V system lenses?

Hi all,

One can find several comparisons between the XCD lenses for the Hasselblad X1D (II) mirrorless, medium-format digital camera and the full-frame (35mm) Otus lenses made by Zeiss on the same camera (using a suitable adapter, of course), as e.g. done by Usman Dawood:

Hasselblad X1D and the Zeiss 85mm Otus: The Ultimate Combination?

I'm rather curious about how the XCD lens lineup match up against the classic V system lenses made for the Hasselblad 500-series film cameras by Zeiss (C, CF, etc.) using Hasselblad's XV adapter for the X1D (II) as far as the photo quality / characteristics are concerned, but I couldn't find such a comparison so far.

Of course, I'm not considering features such as autofocus capabilities (which the V system lenses obviously don't have), I'm really trying to make an apples-to-apples comparison here. Just looking at the spec sheets provided by Hasselblad in its website and e.g. the Zeiss spec sheets available at the Hasselblad Historical web page, one can see that (at least on paper) the XCD lenses are faster and are supposed to have better color rendition since they are apochromatic lenses. However, how do they compare against old flagships such as the super-low-distortion 100mm Planar in a "real life" situation - that is, on the photos?

I mean, my point is: apart from autofocus and lower f-stops, is there any other reason for which the XCD lenses are objectively superior to the old Zeiss V system lenses as far as the final result is concerned, and therefore justify Hasselblad's marketing and price tag? I guess color rendition should be better due to apochromaticity, but that is on paper... How about sharpness / bokeh / etc.?

Any links to such analyses / photos are welcome!

You aren't seeing much info about this combo simply because it isn't practical yet. Unlike the adapter for electronic H lenses, the adapter for mechanical V lenses has no ability to operate their leaf shutter. You must fall back on the X1D sensor-based electronic shutter, which in these large MF sizes isn't as effective or usable as it is in smaller-sensor cameras. It constrains your choice of shooting conditions and subjects, and doesn't make the best use of the glass in front of it.

Reports are mixed from those who have tried the V lenses on the Fuji GFX (which has the same sensor as X1D but a more versatile standard focal plane shutter) or Hasselblad H bodies with the same sensor. The crop factor is pretty strong, and some of the V lenses aren't quite up to snuff on the demanding 5.3 micron pixels. It depends what qualities of the V lenses you prize most: you'll get the color rendering and other factors, but absolute resolution won't seem as good as it was on 6x6 film or the older, larger CCD sensors that were commonly used with V lenses a decade ago. The cream of the bunch like 100mm Planar and 250mm Super Achromat still hit the mark on 50MP 33x44 sensors, but many popular focal lengths long considered superb on film (like the lovely 60mm Distagon) can disappoint. Roughly speaking, bokeh is comparable between X and V assuming similar focal lengths: both are hamstrung by pentagonal diaphragms, but the different optics have some effect.

The V lenses are a nice supplement to an X1D kit if you already own them, but it probably isn't worthwhile to buy them instead of dedicated X lenses unless most of your work is very static, and a comparable X lens is too expensive. The X lenses seem expensive because they are current "boutique" items with costly high-speed leaf shutters and digital-optimized glass. The V lenses were designed decades ago with the somewhat lower resolution required by a film frame two or three times larger (the same way fine lenses for 4x5 view cameras are "lower resolution" than XCD lenses). So the current Otus lenses would be a more apples-to-apples Zeiss/Hassy X comparison. Also one needs to remember the bargain price of used V lenses today bears no relationship whatsoever to their historical value: 25 years ago the 50mm Distagon V sold new for more than the current price of the XCD 45mm, even adjusted for inflation.

FWIW, over the years I've occasionally been able to use my Zeiss V lenses with several digital backs on my 500cm and elx bodies (50, 60, 80, 100, 120, 150, 250). They performed rather nicely on the old Phase One P25+, a CCD back with large sensor much closer to 645 film size than the X1D. They performed less predictably with the newer Hasselblad CFV-50c back, which for all practical purposes is the same Sony sensor as the X1D. Some lenses like the Distagons and 150/250 Sonnar faltered a bit on the smaller denser 33x44 sensor. Not enough to bother me, but perfectionist pixel peepers would be non-plussed. Possibly this is down to the greater precision needed for focus, which the old film bodies are hard pressed to deliver with digital back attached.

I've also enjoyed my V lenses on 35mm-format (24x36) sensor cameras like Nikon D700, D850, Canon 6D and Sony A7II. The 50mm Distagon, 100mm Planar and 250mm Sonnar are especially sweet on 24x36. If they weren't so large and clumsy, I'd replace some of my Nikkors with my V glass. In the end, how you feel about various performance characteristics will determine your satisfaction with V glass on the X1D (that, and whether the electronic sensor shutter limitation lends itself to your work). Some photographers lose their minds at the slightest hint of CA, I'm much less picky about that and other flaws. The distinctive way the V lenses draw an image is something I really like, that often transcends aberrations. Very subjective.

You aren't seeing much info about this combo simply because it isn't practical yet. Unlike the adapter for electronic H lenses, the adapter for mechanical V lenses has no ability to operate their leaf shutter. You must fall back on the X1D sensor-based electronic shutter, which in these large MF sizes isn't as effective or usable as it is in smaller-sensor cameras. It constrains your choice of shooting conditions and subjects, and doesn't make the best use of the glass in front of it.

Hmm... Good point, I didn't pay attention to the fact that the XV adapter cannot give control of the V lenses' leaf shutter to the X1D body. This is certainly a handicap for the use of V lenses on this camera, considering the fact one has to use the on-sensor electronic shutter (at least for now... Until Hasselblad or other vendor comes up with a more functional adapter than the XV).

Reports are mixed from those who have tried the V lenses on the Fuji GFX (which has the same sensor as X1D but a more versatile standard focal plane shutter) or Hasselblad H bodies with the same sensor. The crop factor is pretty strong, and some of the V lenses aren't quite up to snuff on the demanding 5.3 micron pixels. It depends what qualities of the V lenses you prize most: you'll get the color rendering and other factors, but absolute resolution won't seem as good as it was on 6x6 film or the older, larger CCD sensors that were commonly used with V lenses a decade ago. The cream of the bunch like 100mm Planar and 250mm Super Achromat still hit the mark on 50MP 33x44 sensors, but many popular focal lengths long considered superb on film (like the lovely 60mm Distagon) can disappoint. Roughly speaking, bokeh is comparable between X and V assuming similar focal lengths: both are hamstrung by pentagonal diaphragms, but the different optics have some effect.

Ok, this is the kind of info I was looking for, but I'd like to see this on photos somewhere... I'l try to look for usage of V lenses on the Fuji GFX to have a better impression.

FWIW, over the years I've occasionally been able to use my Zeiss V lenses with several digital backs on my 500cm and elx bodies (50, 60, 80, 100, 120, 150, 250). They performed rather nicely on the old Phase One P25+, a CCD back with large sensor much closer to 645 film size than the X1D. They performed less predictably with the newer Hasselblad CFV-50c back, which for all practical purposes is the same Sony sensor as the X1D. Some lenses like the Distagons and 150/250 Sonnar faltered a bit on the smaller denser 33x44 sensor. Not enough to bother me, but perfectionist pixel peepers would be non-plussed. Possibly this is down to the greater precision needed for focus, which the old film bodies are hard pressed to deliver with digital back attached.

Interesting... In fact, I'm curious (as many out there) about how the upcoming CFV II 50c attached to a 500-series mechanical body will fare in this respect. Given that sensor size is a factor and that won't change from the previous iteration, it seems that the problems you pointed will remain. As a matter of fact, I'm more interested in the CFV II digital back for use in my 503cx than in the X1D itself or on the CFV II companion (?) 907X. It's a pity that Phase One no longer makes backs for other than their own cameras.

I've also enjoyed my V lenses on 35mm-format (24x36) sensor cameras like Nikon D700, D850, Canon 6D and Sony A7II. The 50mm Distagon, 100mm Planar and 250mm Sonnar are especially sweet on 24x36. If they weren't so large and clumsy, I'd replace some of my Nikkors with my V glass. In the end, how you feel about various performance characteristics will determine your satisfaction with V glass on the X1D (that, and whether the electronic sensor shutter limitation lends itself to your work). Some photographers lose their minds at the slightest hint of CA, I'm much less picky about that and other flaws. The distinctive way the V lenses draw an image is something I really like, that often transcends aberrations. Very subjective.

I guess so, because the crop factor is so large you are close enough to the lens axis to get a significantly lower distortion (depending on the lens), but these lenses are really large and heavy compared to full-frame 35mm lenses of the same focal length, so it's not something one would want to use on a 35mm camera most of the time. Color rendition and contrast are of course highly subjective - that's the reason I love classic German glass and loathe Canon glass as it shows on photos, for instance.

FWIW, over the years I've occasionally been able to use my Zeiss V lenses with several digital backs on my 500cm and elx bodies (50, 60, 80, 100, 120, 150, 250). They performed rather nicely on the old Phase One P25+, a CCD back with large sensor much closer to 645 film size than the X1D. They performed less predictably with the newer Hasselblad CFV-50c back, which for all practical purposes is the same Sony sensor as the X1D. Some lenses like the Distagons and 150/250 Sonnar faltered a bit on the smaller denser 33x44 sensor. Not enough to bother me, but perfectionist pixel peepers would be non-plussed. Possibly this is down to the greater precision needed for focus, which the old film bodies are hard pressed to deliver with digital back attached.

In due time: regarding manual focusing precision, I reckon that the 100mm Planar's success on the Fuji GFX (and on MF digital cameras on the same sensor) has to do with the fact that, in addition to its extremely low distortion, its focusing mechanism is reputedly very precise, so it should be up to digital standards. The only problem is that, with such a crop factor, its effective focal length gets a bit long and therefore excludes some of its applications. Pity that the Distagons don't seem perform so well in that respect, according to your finds.

I still couldn't find any reports on how well Hasselblad / Zeiss V system lenses fare on the Fuji GFX, but I did find some photos on Flickr using the CFV-50c back. Not many using the 100mm Planar, though, but I could find several nice examples using the 120mm Makro Planar. Unfortunately, that setup kind of precludes the kind of comparison I asked for, at least until one gets the 907X / CFV II combo to make such a test.

Interesting... In fact, I'm curious (as many out there) about how the upcoming CFV II 50c attached to a 500-series mechanical body will fare in this respect. Given that sensor size is a factor and that won't change from the previous iteration, it seems that the problems you pointed will remain. As a matter of fact, I'm more interested in the CFV II digital back for use in my 503cx than in the X1D itself or on the CFV II companion (?) 907X. It's a pity that Phase One no longer makes backs for other than their own cameras.

I stand corrected - actually, the IQ3 digital backs from Phase One can be used on Hasselblad H- and V-series camera bodies (but not the IQ4). The problem actually is the car-grade price of those...

Prices on the more desirable digital backs for Hasselblad V series have remained stubbornly high: lots of people still love the body and Zeiss lenses. You can get excellent Imacon, Sinar and Phase backs for less than $1200, but those are the oldest "blind" backs with no screen that require tethering to a computer. The least expensive back I would consider practical is the Phase One P25, which at least has a large (near-645) sensor, rudimentary screen, and ability to save files on a CF card. Those go for about $3000 still.

I liked the Hasselblad CFV-50s, except for the idiotic, ugly, un-ergonomic external battery. The price was a bargain next to a comparable Phase One with the same sensor, but still way out of range for most Hasselblad enthusiasts (including me). Relief may be coming, however: pricing for the CFV-50c mkII appears to be dramatically less. The original was introduced at $15K, eventually dropping to about $10K. The new version is available for pre-order right now in a package deal including the new 907 body for just $7500. Assuming that remains the base price, the back alone without the 907 body will likely be $5995 or less: much more accessible to many more Haselblad owners.

Now if only Haselblad would get its finances in order and actually mass produce the thing...

The potential market for the 907x is so small its a rounding error. After the initial rush of die-hard SWC fans buy it to finally free themselves from cropping pain and lens cast issues, thats it. Hasselblad needs every last penny it can shake out from the sofa cushions of its former legion of V enthusiasts: theres no way the CFV-50CII doesn't eventually become an independent product. The model name itself still tags it as a V-oriented item: if there wasn't an intent to make a play for the V users with an affordable modern back option, the 907x would have been easier and cheaper to produce as an integrated standalone camera.

Of course at this point Hasselblad management is sharing the same gin-soaked Ouija board that Nikon relies on for critical decision making. I wouldn't put it past them in the least to delude themselves the 907x would be a coherent product with mass appeal, and only offer the back with it as a set. Doesn't really matter as long as they actually produce them in some plausible quantity: at $7500 for the set its still half the price of the first CFV-50c, with better live view and neater internal battery. Many happy V users would buy at that price and dump the unwanted 907x on eBay, much as Canon 6D and Nikon D660/D750 buyers dumped their subsidized 24-105 kit lenses.

Well, here we are... the 907X has been officially released at $6399:

907X 50C - Hasselblad Store

The best review I've found on it, especially regarding comparison between Zeiss V glass and XCD lenses, was made by Jay P. Morgan on his The Slanted Lens site, reposted at PetaPixel:

Hasselblad 907X Hands On Camera Review - The Slanted Lens

Hasselblad 907X Hands-On Review and Vintage Lens Test

As usual when using vintage glass on modern digital cameras, manual focus precision becomes more critical than on film. This is also emphasized in the CFV II 50C manual. It seems to me that Zeiss glass holds up pretty well in that respect, though (albeit maybe not up to XCD autofocus precision standards), probably thanks to these lenses' superb microcontrast.

Mike Aubrey commented above on PetaPixel regarding the best choices of V glass for the CFV II 50c (in his opinion):

In terms of vintage lenses that are going hold up best on this. These are the best resolving lenses. Note: in the first group, normal people can probably only afford one of these. On the other hand, if you're spending $6000 on this camera, maybe they can also afford $5,000 for a Distagon 40mm IF FLE, which is competitive with any modern Zeiss lens (because it is one).

 

Superb:

Distagon f/4 40mm IF FLE

Planar f/3.5 100mm

Sonnar-Superachromat f/5.6 250mm

Tele-Superachromat f/5.6 350mm IF

 

Great:

Distagon f/4 50mm FLE

Makro-Planar f/4 120mm

Sonnar f/4 180mm

 

Good:

Distagon f/3.5 60mm

Planar f/2.8 80mm

Some of his recommendations - both best (Planar f/3.5 100mm, Sonnar-Superachromat f/5.6 250mm) and perhaps not so great (Distagon f/3.5 60mm) - happen to coincide with orsetto's made above. It seems to me, though, that he based his judgement on measured lens sharpness (MTF charts, etc.) rather than actual experience with the combinations. What do you think?

Just a side note to this very interesting conversation. I've seen it written more than once that focus is critical when using a digital back on a V System body. The explanations I have seen many times mention the thickness of film emulsion being more forgiving than the relatively flat surface a of a CCD. Apparently film "absorbs" focus error that a CCD can not because of the emulsion thickness. I surely don't know enough to argue with this logic - it makes sense to me.

Where I can add to this is mention of the condition of mirror pads in these sometimes 60 year old machines. Hasselblad placed the mirror on three pads within the mirror frame. They are arranged pretty much like a triangle with one pad at the center top of the mirror (the pivoting end of the mirror frame) and two in the corners at the bottom (closest to the lens). These pads "perish" as the Brits like to say. This allows the mirror to move up and down in its frame and makes it unlikely the mirror is restoring to the same point each time the advance knob resets the mirror. This situation is a contributing cause of images that appear in focus on the ground glass but that are not in focus on the film plane.

Why Hasselblad chose to use only three pads rather than one in each corner of the mirror is a question I would love to know the answer to. Regardless though, its a safe bet that any V-Series body (including 1600F and 1000F) that has spent the last 20 years in a closet, will need new mirror pads. Does Hasselblad in NJ replace the pads when a body comes in for service? I would hope so. Do other specialists out there do this as well when they service a body? Again, I would hope so but I don't really know. What I do know is that focus errors when using a digital back will only be made worse if the mirror pads are shot and your mirror is moving.

When the pads are shot its fairly easy to detect. Remove the lens and rotate the body 180 degrees so that the tripod mount is facing upward. With a toothpick or something that won't scratch the mirror (eraser end of a pencil, a q-tip, whatever) lightly put pressure on the mirror glass to see if it moves within its metal frame. Release the pressure and see if the mirror glass moves back to the original position. Any movement indicates the mirror is not being supported tightly and the pads may need replacing.

The explanations I have seen many times mention the thickness of film emulsion being more forgiving than the relatively flat surface a of a CCD. Apparently film "absorbs" focus error that a CCD can not because of the emulsion thickness.

Where have you been Andy?

CCD sensor technology gave way to CMOS at least a decade ago.

WRT emulsion thickness; it most certainly does limit sharpness.

Colour film emulsions may have up to 20 layers, apparently, and a conservative estimate of that emulsion thickness might be 20 microns - possibly more. (Film manufacturers are seemingly a bit shy about putting hard numbers on the thickness of their emulsions.)

Anyhoo. Let's take a figure of 20 microns thickness and calculate the point spread between top and bottom of such an emulsion. With an 80mm lens and an aperture of f/2.8, it works out that there's a point spread of about 7 microns, meaning that theoretically only 70 line-pairs/mm would be resolvable. And that's without taking account of any diffusion of the light through turbidity of the emulsion.

That figure improves as the aperture gets smaller, but there's quite a small window of opportunity before diffraction starts to take resolution away again.

So any lens resolution much in excess of 70 lppmm would be largely wasted on film.

FWIW, the best 300mm telephoto lens I own is a Mamiya Sekor C, designed for the M645 system. It totally outshines anything I've yet to come across designed specifically for a 35mm system.

Most of the rest of my Mamiya 645 lenses also perform exceptionally well on a high-res full-frame digital sensor, and generally better than big-name 35mm system lenses from the film era.

I guess Canon, Nikon and the like made most of their lenses 'good enough' for the 35mm film of the time, and not much better.

Where have you been Andy?

CCD sensor technology gave way to CMOS at least a decade ago.

LOL. Well I certainly haven't been at the front of the line. My archaic P45+ has CCD technology. Rather than step into the Roaring 20s, I'm happy where I am and instead, put a new roof on my house. Thanks for the theory lesson though.

Thanks for the theory lesson though.

Sorry! Didn't mean to lecture Andy.... but the question was asked.

Keeping the rain off is obviously quite important. Although if someone offered me a 400mm f/2.8 lens to live in a tent for a month, I might be tempted.

No. On second thoughts, I'd definitely be tempted.

Thanks for all the comments. I think I've been able to get a decent overall picture of the situation concerning using the CFV II 50c back with a V-system camera and lenses, which to some extent also applies to using adapted V-system lenses on Fujifilm GFX cameras. To summarize:

• The small pixel size of the CFV II 50c makes accurate focusing critical. It baffles me that, unlike the original CFV back, the 907X kit doesn't include the split focusing screen with the X1D / 907X form factor framelines, just a dinky focusing screen mask. The split Fresnel at the middle helps enormously with fine tuning focus, if my previous experience with 35mm film cameras (Leica R6, Minolta SRT-101, Kodak Retina Reflex III) has any worth. You can still buy the screen separately, of course, but it's a pain. Alternatively, you can also lift the mirror and use e.g. focus peaking with live view.
   
  
• Only a few of the V-system lenses are up to the more exacting digital standards of today - most notably, it seems, the 40mm f/4 FLE Distagon, the 100mm f/3.5 Planar and the 250mm f/5.6 Superachromat Sonnar (particularly the latter being an apochromatic lens, just like the XCD lenses). The 120mm f/4 Makro-Planar and 180mm f/4 Sonnar also seem to deliver on the CFV backs, judging from photo samples. For me, the 100mm Planar + 120mm Makro-Planar combo seems especially compelling to that end, since these lenses nicely complement each other (also on film, obviously) - both have similar lengths and perform exceptionally well on the whole aperture range, with the 100mm being the sharpest near infinity (with its famed ultra-low distortion there) and the 120mm being the sharpest at close range (being a lens optimized for close-ups). Moreover, both lenses have a very precise focusing ring.
   
  
• Even though the 907X opens access to modern XCD glass, it only makes sense to buy it over (say) the X1D II if you are already invested into the V system, especially considering that the X1D II costs about USD 500 - 600 less than the 907X and has more features. Of course, new XCD glass, although arguably superior and more adequate for digital photography, is much more expensive than used V glass (especially if you already own it ;) ), but one may also argue that if you have USD 5800 - 6400 to spend on a camera body, you probably can also afford to buy at least one or two XCD lenses instead of a whole V-system setup. On the other hand, that's not what the CFV II 50c back is all about - it's about the whole experience of shooting with a V system you already own being transported into the digital age, which is great provided one watches out for the above provisos. That's clearly the market Hasselblad is aiming at with the 907X, with the possibility of inviting V-system users to try the XCD lenses in time.
  

[...] and the 250mm f/5.6 Superachromat Sonnar (particularly the latter being an apochromatic lens, just like the XCD lenses). [...]

Nitpicking, but...

The Sonnar Superachromat is not an Apochromat, but a Superachromat. Superachromatic correction (At least four colours in focus, with a secondary spectrum so minimal that it doesn't show itself) is a class above apochromatic correction (three colours in focus, the rest close but probably not). Superachromats can focus near IR in the same plane as visual light. Not many (if any) apochromats can.

Thanks for all the comments. I think I've been able to get a decent overall picture of the situation concerning using the CFV II 50c back with a V-system camera and lenses, which to some extent also applies to using adapted V-system lenses on Fujifilm GFX cameras.

While it seems rather strange that anyone would "spend $7-10K to use old obsolete lenses", the situation isn't really that cut and dried. Most potential purchasers of the CFV50cII/907x, X1D series or Fuji GFX series aren't buying these expensive bodies to use only with old Zeiss V lenses, nor are they buying the bodies and then going out to buy a set of old V lenses from scratch instead of the native digital lenses. The typical buyer of these cameras either already owns several V lenses, or plans to perhaps buy one or two as supplements to a primarily current lens kit. IOW, when the V lenses are essentially "free of cost," using them with these new cameras is less of a financial commitment than an artistic or sentimental choice.

The ergonomics of the specific camera body come into play as well. Despite the advantages of their integrated fully-digital mirrorless design for manual focus lenses, the X1D and GFX are almost absurdly clumsy with V lenses (seriously: slap a mount adapter and the 40mm Zeiss IF lens on the X1D and tell me you feel inspired and motivated by the handling of that combo). The X1D was clearly (and exquisitely) designed to be the ultimate medium format digital hand camera, with coordinated AF lenses of fairly compact size. Ditto the Fuji GFX50R, tho the other GFX bodies are a bit larger (as the Fuji lenses are larger than XCD glass).

Admittedly only a few of the shorter XCD and GX focal lengths could really be called compact, but the addition of AF and AE compensates greatly. Adding a bulky adapter and manual focus glass from Zeiss, Pentax or Mamiya upends that compromise: the lens hangs that much farther out in front of the body, lack of electronic interface means a lot more fiddling with controls, and if your V lens isn't the very latest CFi version the dog slow focus ring can be a real buzz kill. You'd likely only want to deal with these tradeoffs in certain shooting situations, or to use one particular favorite lens. Mostly you'd be using native lenses on the X1D or GFX cameras.

The Hasselblad 907x/CFV50cII is a different animal altogether. The digital back was expressly designed for use with Hasselblad V camera bodies and lenses, similar to the old Phase and Leaf backs from when Hasselblad dominated early digital studio photography (but with modern sensor and features at 1/8th the retail price). It is the perfect digital conversion accessory for diehard V system enthusiasts who can seamlessly switch between film back and digital back using the same familiar V cameras and lenses. While there can be issues with the aging cameras and manual focus that make them lag behind integrated modern digital bodies/lenses in technical perfection, if you love the V experience and can afford $6K the CFV50cII is a win-win.

Hasselblad evidently decided not to offer the current mkII on its own directly to holdout users of the V system, instead preferring to bundle it with the unusual 907x body in an effort to boost market penetration of the XCD lens mount. When used with native 21mm or 30mm wide lenses, the 907x + CFV50cII provides handling comparable to the legendary SWC film camera (which unfortunately does not work as well with a current digital back vs film). Since lack of ultrawide options is a drawback of the V digital platform, bundling the 907x with CFV50cII at an attractive price point makes it a "free" SWC replacement (while promoting sales of the XCD 21mm and 30mm to complete it).

Using V lenses on the 907x would require the same adapter as for the X1D. The the waist-level ergonomics of 907x might seem to b an improvement over X1D for V glass, but the very limited body controls of the 907x make it less practical in that mode. And you have the same difficulty of no physical shutter mechanism the X1D entails. Its really a dedicated novelty body for fully coupled XCD lenses: a supplement to to fill in the "digital SWC gap" for V shooters.

My feelings exactly orsetto, apart from the "SWC factor" which I hadn't thought of. Indeed, if you think about it, the optional grip and viewfinder for the 907X are both strongly remniscent of the SWC. I had no idea that the CFV backs wouldn't work so well on the SWC - my impression was otherwise.

Anyhow, as I said above, I also think that providing the CFV II 50c as part of the 907X is mostly a kind of invitation to the V-system users for entering the XCD lens ecosystem.

Another (maybe silly) thought that occurred to me is that the V system cameras coupled with the CFV II 50c, the focusing bellows extension (using, say, the 135mm Makro-Planar lens) and the negative holder accessory for the latter may be an interesting platform for scanning medium-format negatives, similar to the Nikon ES-2 adapter for scanning 35mm negatives. A quick calculation shows that such a scanning rig may achieve almost 2800 dpi of optical scanning resolution with the CFV II 50c (taking into account the 37.5MP resolution of the 32.9mm x 32.9mm square crop of the CFV II 50c sensor and the resulting 0,5875x crop factor as compared to 6x6 = 56mm x 56mm). I know, the 907X alone is more expensive than, say, a 4000-dpi Nikon Super Coolscan 9000 ED, but if you already have the 907X for taking pictures... The focusing bellows extension, the 135mm Makro-Planar and the negative holder accessory can be considerably more affordable in the used market.

Nitpicking, but...

The Sonnar Superachromat is not an Apochromat, but a Superachromat. Superachromatic correction (At least four colours in focus, with a secondary spectrum so minimal that it doesn't show itself) is a class above apochromatic correction (three colours in focus, the rest close but probably not). Superachromats can focus near IR in the same plane as visual light. Not many (if any) apochromats can.

I didn't know that, interesting. Thanks for the info!

I had no idea that the CFV backs wouldn't work so well on the SWC - my impression was otherwise.

The issues with SWC 38mm Biogon and modern digital backs vary in severity depending on the particular sensor: some users find it perfectly acceptable. But generally speaking re current backs, the issues are similar to those confronted by fans of symmetrical wide Leica M, Zeiss, and CV rangefinder lenses when adapted to mirrorless 24x36 cameras like the Sony A7R series, Nikon Z or Canon R. Modern sensors like the 50MP Sony in the CFV50C and CII employ microlens arrays which conflict with the steep Biogon imaging light rays at edges/corners (rear element of the SWC nearly touches the sensor glass). The result is color casts, local contrast reduction, and add'l glitches contributed by the sensor cover glass.

Historically, digital medium format had been slightly less problematic with the SWC. Earlier CCD sensor backs had lower resolution with larger pixels, larger sensor sizes approaching film-era 645, no microlenses, and thinner cover glass. So the SWC Biogon worked reasonably well with those. As CCD resolution increased, the SWC became somewhat less compatible. Then Sony's mass-produced 50MP 33x44 CMOS sensor upended the entire MF market. The wide variety of CCD sensor sizes and MPs vanished, replaced by a uniform, "mini-MF" format with the advantages of 50MP CMOS but also its drawbacks.

The SWC is a killer single-purpose camera designed to make stunning wide pics in 6x6 format. Strike One against adapting it to digital CFV50cII is the ludicrous 33x44 crop factor wiping out its raison d'etre. Even if you're willing to deal with the silly crop factor, Strike Two is the potential for color casts and artifacts. While imaging apps like Capture One and Phocus employ LCCs to do a capable job of ameliorating these digital issues with the SWC, photographers of more exacting subjects like architecture and fine art find such corrections a bit lacking vs raw results obtained with a current, digital-optimized wide lens made for a native mount (i.e. the 21mm or 30mm XCD lenses on 907x or X1D).

Hence Hasselblad's motivation for bundling the 907x XCD-mount body with digital backs ostensibly marketed to owners of V system bodies/lenses. The bundle encourages continued enjoyment of most of the classic V system in digital mode, while acknowledging the XCD lenses are more suitable for digital superwide. Promoting the CFV50cII as a common digital sensor module swappable between V and X systems is a rather clever solution to the SWC digital dilemma.

Another (maybe silly) thought that occurred to me is that the V system cameras coupled with the CFV II 50c, the focusing bellows extension (using, say, the 135mm Makro-Planar lens) and the negative holder accessory for the latter may be an interesting platform for scanning medium-format negatives [...] I know, the 907X alone is more expensive than, say, a 4000-dpi Nikon Super Coolscan 9000 ED, but if you already have the 907X for taking pictures... The focusing bellows extension, the 135mm Makro-Planar and the negative holder accessory can be considerably more affordable in the used market.

You mention both 907x body and CFV50cII back: the 907x may not be suitable for this task (workable with an V>X lens mount adapter, but not optimal). To 'scan' 6x6 film with the V mount 135mm and bellows/slide copier, you'd probably use a V body and CFV50cII. Whether this would offer appreciably better 'scanning' performance than a 24x36 camera with appropriate macro lens and accessories is open to question.

Remember the 'blad digital sensor is not 6x6 or 645 but 33x44, so it isn't quite a direct 1:1 'scan'. You'd either stitch multiple 1:1 sections, or adjust the magnification to fit the sensor size (same as with a 24x36 camera). The advantage of using a smaller 24x36 digital camera to 'scan' 6x6 film is easier handling, wider range of macro/micro optics, and wider range of sensor "flavors". Interestingly, neither MF digital mirrorless brand (Hasselblad or Fuji) offers a truly practical native macro lens suitable for scanning film. Both the XCD and GX macros are superb but huge, slow to AF, have frustrating manual focus by wire, and don't go to 1:1 without adding an extension tube. A 'V' body with 135mm + bellows, or 24x36 with modern macro, might be easier to control for scanning purposes.

Phase One offers a super-ultra-premium medium format "film scanning" workstation comprising a digital back in either 50MP 33x44 or 100MP 40x54 sensor size, Schneider Apo-Digitar Aspheric macro lens, and custom copy stand/film holder mechanics more solid than the Brooklyn Bridge. Light years out of the price range of us ordinary folk: even museums lease it instead of buying. But the basic premise is a scaled-up version of the rig you suggested, and similar rigs cobbled together and discussed in various other forum threads. Camera-based film scanning can work great, tho In some respects a dedicated Nikon 9000 or Hasselblad/Imacon film scanner is still preferable. Esp for color negative films that are tricky enough to capture in arcane scanner software (never mind standard camera raw apps).

You mention both 907x body and CFV50cII back: the 907x may not be suitable for this task (workable with an V>X lens mount adapter, but not optimal). To 'scan' 6x6 film with the V mount 135mm and bellows/slide copier, you'd probably use a V body and CFV50cII. Whether this would offer appreciably better 'scanning' performance than a 24x36 camera with appropriate macro lens and accessories is open to question.

 

Remember the 'blad digital sensor is not 6x6 or 645 but 33x44, so it isn't quite a direct 1:1 'scan'. You'd either stitch multiple 1:1 sections, or adjust the magnification to fit the sensor size (same as with a 24x36 camera). The advantage of using a smaller 24x36 digital camera to 'scan' 6x6 film is easier handling, wider range of macro/micro optics, and wider range of sensor "flavors". Interestingly, neither MF digital mirrorless brand (Hasselblad or Fuji) offers a truly practical native macro lens suitable for scanning film. Both the XCD and GX macros are superb but huge, slow to AF, have frustrating manual focus by wire, and don't go to 1:1 without adding an extension tube. A 'V' body with 135mm + bellows, or 24x36 with modern macro, might be easier to control for scanning purposes.

 

Phase One offers a super-ultra-premium medium format "film scanning" workstation comprising a digital back in either 50MP 33x44 or 100MP 40x54 sensor size, Schneider Apo-Digitar Aspheric macro lens, and custom copy stand/film holder mechanics more solid than the Brooklyn Bridge. Light years out of the price range of us ordinary folk: even museums lease it instead of buying. But the basic premise is a scaled-up version of the rig you suggested, and similar rigs cobbled together and discussed in various other forum threads. Camera-based film scanning can work great, tho In some respects a dedicated Nikon 9000 or Hasselblad/Imacon film scanner is still preferable. Esp for color negative films that are tricky enough to capture in arcane scanner software (never mind standard camera raw apps).

Actually, I only mentioned the 907X cost-wise, because you have to buy the whole thing to get the CFV II 50c. I wasn't even considering using the 907X itself as part of a scanning rig, I really was only thinking of a V-system camera with the CFV II 50c back, the focusing bellows with the negative holder accessory and (say) a macro lens like the 135mm Makro-Planar, which is meant to be used with the bellows setup anyway. And yes, the bellows makes it much easier to achieve the proper scale to that end, that's why I was thinking of this setup. The scanning resolution I estimated for this rig does take into account the fact that the square crop of the CFV II 50c sensor is 37.5 MP in a 33mm x 33mm square and not the original 56mm x 56mm from the 6x6 format. The only thing I'm unsure of is whether 2800 dpi is enough to resolve the fim grain of, say, a Kodak Portra ISO 400 film or a Ilford XP2 ISO 400 (which are the films I use) without pixel artifacts. The Phase One scanning rig you mentioned seems to indicate that it is, since its smaller sensor option has the same scanning resolution. The Schneider-Kreuznach Apo-Digitar Aspheric lens is probably more resolving than the Makro-Planar, though.

I'm afraid I can't offer a comparison of V series glass vs. XCD lenses on digital. What I can do, which may be useful to some following this thread, is show full-resolution what a couple of the V series lenses do on a fairly old digital back. And I can give my impressions of a few other lenses used the same way.

I run a portrait studio in West Orlando, and my setup is a Hasselblad 553ELX with a 2004-vintage Sinarback 54M mounted on it. It's got the venerable 22-megapixel (36 x 48mm) Kodak KAF-22000 CCD sensor that was common in many backs of that era. This particular back has no screen, no battery, and no memory card slot, so it has to be tethered to an older MacBook Pro.

These are full-resolution JPEGs (or close to; I may have slightly cropped one or both of the portraits). They've had a bit of post-processing, including a touch of NIK Sharpener, but you can see what's there for all practical purposes. The two portraits were taken with, I think in both cases, the 180mm Sonnar (CFi version), the very tight face shot with an extension tube, can't remember which one, but it was likely the 10mm and 21mm used together (and if it wasn't that combo, it was the 55mm by itself). The final one is a closeup of the fibres of a jute coffee sack hanging on my studio wall, shot with the 120mm Makro-Planar on the Hasselblad Auto Bellows at maximum extension (on both the lens and the bellows). I just wanted to see what that combo could do when pressed to the extreme; I was fairly careful, if not scrupulously so, in trying to get the camera aligned properly to the plane of the wall. All three were shot with strobes.

http://www.presquevu.com/x8505.jpg

http://www.presquevu.com/vs35.jpg

http://www.presquevu.com/macro.jpg

The macro shot, by the way, encompassed an area of less than 1.5 x 2 inches.

I also use the 150mm Sonnar CF and at portrait distance it is really, really good. It's not quite as spectacular as the 180, but it's certainly very capable. Plus I have the 80mm Planar CF version which I use for full body shots. At that distance, it's good but not great. But when you get closer and shoot mid-body or nearer with it, it becomes impressively punchy indeed. Finally, I have the floating element 50mm Distagon CF and I've found it quite good, too, although I haven't used it enough in the studio with the digital back to draw any firm conclusions on where it ranks.

But yes, I would class the 180mm and the 120mm macro as outstanding performers on digital. The 150mm Sonnar is very good--it may not be as razor sharp as the XCD lenses, but you can print up to 16x20 inches (and more) with fantastic detail; I've done so. The 80 is a bit meh under some circumstances, and I suspect, from the times I have used the 50mm FLE, that it doesn't lag at all far behind the 180 and the 120.

I hope this is at least somewhat helpful!