Accuracy of LF 4x5 Film Holders?

[mark_tucker2]

When I was reading that guy's question about comparing MF to

LF, and people were listing all the potential negatives of LF, it

was again mentioned about tolerances of the film holders. I

wonder to what degree it actually is a factor?

 

I shoot entirely Type 55 right now. Plus, I generally always shoot

wide open (I'm kinda weird). So, given the inherent short DOF in

LF in general, and then you add shooting wide open (f2.8), I

wonder how that Polaroid neg is in that packet, in there flopping

around at different tolerances for every single sheet.

 

Are we talking that say, 2mm of play would have a very noticeable

effect on focus? Or would it be more?

 

And someday, if I ever shoot "real film", how much of an issue is

it for shooting wide open? And are there any brands of holders

that are rated better? (I heard a rumor that really one one

company manufactures all the holders, and then they rebrand

them later for sale).

 

If LF is known for such "incredible sharpness" and all the gear is

so precise, and people are looking at and obsessing over these

MTF charts, or whatever you call them, and yet the holders are

letting the film flop around all over the place, how could this be?

Are not the holders the Achilles Heel of LF?

 

Would ReadyLoad reduce those tolerances, even if they cost

more?

 

Sorry for seventeen questions in one post. I'm just trying to

resolve it.

 

-MT, http://www.marktucker.com

[ellis_vener_photography]

1.) it is nowhere near 2mm. maybe 0.2mm at most. 2mm is slightly less than a

tenth of an inch.<P>2.)I've only seen it be a problem when shoot 8x10 in a

near vertical , camera looking down postion where the film was left that way

for some time.<P>3.) Where did you find an f/2.8 view camera lens?<P>4.)

I've had terrific success with film flatness using the Fuji Quickload system

(holder and packet).<P>5.) Not such success using the Ouickload or the

Kodak readyload packets in a Polaroid 545 & 545i holder.<P>6.)The real

possible achilles heel is not the holders by themselves but their alignment

with the plane of focus on the front (lens) side of the groundglass in the

camera being used. Professional and maybe few dedicated amateurs have

been known to test all of their holders for correct alignment with their

camera(s) and toss the ones with alignment problems.<P>7.) People who

obsess over published MTF charts, etc. have better things to do with their

time -- like actually make photographs -- but they just haven't worked up the

courage to actually do so.<P>8.) And yes fidelity, elite andLisco holders are

all basically the same item wth different names. Maybe at some poiint in the

past these were different companies.<P>9.) The Polaroid negative doesn't

"flop around" in the polaroid holder, it is held in place under some degree of

tension.<P>10.) Large format is known for incredible sharpness when the

lenses are used at their "prime" apertures, which are generally in the f/16 to f/

22 range; when the camera is carefully focused; when the phootgrapher is

careful about their work; when an image is enlarged to the same size as an

image made on a smaller negative.

[mark_tucker2]

Ellis,

 

Thank you. I'll add a couple more:

 

"3.) Where did you find an f/2.8 view camera lens?"

None of your business! I protect my sources, and they take care

of me. (Insert smile icon here).

 

There's an F2 125 on ebay now, and the guy claims it's a view

lens, but it looks like a stat camera lens. The f2 though, certainly

got my attention. My rule: nothing slower than 2.8, and then

ducttape the fstop ring down solid!

 

"4.) I've had terrific success with film flatness using the Fuji

Quickload system (holder and packet)."

Can you shoot non-Fuji readyload style film in Fuji QL holders

without incident? TMAX 400 etc?

 

I'd probably be well advised to buy two of the Fuji holders, in

case I dropped one in the middle of a job.

[steve_hamley]

Mark,

 

I have used both Kodak Readyloads and Fuji Quickloads in the Kodak holder without problems. No doubt it is prudent to use the manufacturer's recommended holder for a given film. Kodak also gives instructions for using the Polaroid 545i holder in boxes of Readyloads.

 

I believe the consensus is that Polaroid holders are less desirable from a flatness standpoint with non-polaroid films although they will work with all 3 manufacturer's packet films, the Fuji holder only works with Fuji products, and the Kodak works with both Fuji and Kodak packet film.

 

Thanks!

 

Steve

[squareframe]

Mark,

 

as a fellow member of the f1 club, you might be interested in my spherical film holder. fits right in with our duct-taped loupes, zorks, and oblique movements. here the world is obsessing over film-flatness and I have spent my days trying to avoid it.

 

film flatness doesn't appear to be an issue, other than at the molecular level, as long as the film plane coincides with the ground-glass plane.

[armin_seeholzer]

Hi Mark

 

Yes the older holders are not always holding the film very flat also the newer ones for wide open shoots.

In my opinion the best holder for two sheets is from Toyo, and if filmflatness is best with the single sheet holder from Sinar special for shooting wide open and very critical applications!

I think Schneiders Vakuumholder is not anymore in production.

Good luck!

[pete_andrews]

<i>"as long as the film plane coincides with the ground-glass plane."</i> - But that's the very issue, isn't it Daniel?<p>There isn't even an ISO standard for LF film plane register, only a concensus that it should be 4.76mm, or perhaps 4.8, or maybe 4.9.... no wait..... perhaps 5mm would be better. Well, since Sinar and Toyo are now the only two remaining LF camera makers to also make filmholders, they ARE the deciders of the defacto standard. And not many people are going to shell out for Sinar's overpriced product.

[eugene_singer]

Mark, you are really fortunate. Since you only shoot with the lens wide open, you don't even need to use a lens. Get an assortment of pinhole plates, and use them instead. You'll get a similar result to using a lens wide open, and still be able to have infinite depth of field, which cannot be obtained with a wide open lens. Toyo double cut film holders are rated very high for accuracy, but are more expensive than Lisco-Fidelity holders (which are both made by the same manufacturer- a company in Calif. owned by Calumet). T-Max Readyloads are not available in the 400 speed version, yet. It's advisable to use Kodak Readyloads in the Kodak holder and Fuji Quickloads in the Fuji holder. The Polaroid 545i holder will work reasonably well with both, but you need to close the lens down to, at least f16, if you are concerned about sharpness. Film holder accuracy is not the Achilles Heel of LF. Not understanding the entire process, it's strengths and weaknesses, is the Achilles Heel.

[robert_kennedy]

Eugene makes a good point. Like any tool there are certain ways to use LF. Tolerance-wise unless you are doing something funky, any difference in the holders is irrelevant.

 

Now, if you ARE shooting wide open (definately not the LF standard), and are using a fast lens, your best bet is to probably calibrate your holders with your lenses and mark them appropriately. That is if you are noticing differences (which you could if the lens is fast enough).

[mark_tucker2]

To Robert,

 

Yes, I shoot wide open for no depth most of the time. But where I

*do* focus, I want to be able to trust that it's sharp. I will do some

thorough tests with this Polaroid 545 back and check it.

 

Like this test that I did yesterday:

 

http://www.marktucker.com

 

the focus was only on the tip of the eyelashes. Can't really see it

in the JPG, but it's scary-beautiful in the hi-rez scan. The

eyelashes are 3D.

 

Nothing worse than getting film back and seeing that it

backfocused or frontfocused when shot wideopen.

 

Thank you all for the information.

 

MT

[kcrisp]

Mark: I agree with Daniel. Certainly it is possible that a film holder could be out of wack and spoil a negative. This is not a "problem" ("possibility" is probably a better word) which is a weakness of LF in my opinion. I have lots of filmholders, best guess 30 of them 4X5, going back to the 1940's in construction, a few more than that number in 5X7, many of which are also at least 50 years old, and 12 8X10's which are around 10 years old. I have 4 grafmatics which I use often for a handheld camera. So that makes about 178 "sides" of film holder(s) for flatness issues, and many of the products used date back to before WWII. I have never, ever, had a focus problem caused by a film holder. (An occasional light leak on a really old wooden holder, yes.) Focus issues which were my fault? Yes, a few of those, mostly early on, thinking I didn't need a loupe, or getting careless about checking the focus at the top of a tall subject. Camera movement from wind? Yes, than can happen. The suggestion I saw on this forum about carrying a golf umbrella in the car has helped a great deal with this. A tripod foot which sinks a little during exposure? That happened once. But never a film holder causing the image to focus in front of or in back of what I intended the plane of focus to be. (I have seen ground glass placements which cause this problem, and I fixed it without great effort.) I don't shoot wider open than f:16, except for very rare occasions. I guess it could be, in theory, that my stopping down is masking a problem or issue that I don't know about and have never seen affect a negative. I can see no reason to spend time worrying about something theoretical which has never caused a real world problem. That such a possibility might cause you to avoid the LF would be tragic. I think it is a good practice to write down some details of your exposures, including filmholder used. If you ever have a problem that you think might be caused by this type of registration error, you will know holder it is in no time and a test with a wide open lens will confirm your hunch.

[gary_frost1]

The 'defacto' standard for film holder depth is 0.197 inches.

The GG, film plane is 0.190". This allows for a .007 film base.

My 4X5 HP5+ measures .0075", Provia F100 .009". This tiny difference

is not going to be significant in all but the most extreme conditions.

(How accurately can you focus on the GG with a 10X loupe?)

I wouldn't reject a holder if it was 0.201".

In my experience with a wide range of cameras, (Tachihara, Super Graphic, Old B&J Saturn 75 with both 5X7 and 4X5 backs, old and

new film holders, Fuji Quikload holder, Horseman 6x9 roll back),,, The issue of film registration and flatness just simply has not been a problem. I have used as wide as f/8 but 22 is more typical.

The focus plane and what is sharp and not sharp matches GG to film.

 

I do have a depth micrometer and machine flat to check. I would have

expected to reject or adjust somewhere with this odd assortment of

equipment. I rejected a few old wood holders only because they were

warped. I suspect most of the horror stories occured after someone

messed with the GG back regarding spacers, glass thickness or fresnel

placement.

 

Yes I read posts about all this and did a bunch of testing early on.

It's one of the LF things I no longer worry about. I recently got an

old plate camera and had to reposition the GG for plate camera to

film, so these numbers and measures are fresh in my mind.

 

I think the whole problem is overstated/over-rated. Yes, working with

f/2.8 will put the film plane accuracy to an extreme test. Good luck

and let us know how it goes.

[robert_a._zeichner1]

Mark, The ANSI specification for 4x5 film holders is a depth of .197" +/- .007". While it is pretty reasonable to expect that something made of plastic and aluminum and no doubt assembled by machine should be pretty consistant, this is not always the case. Still, they are amazingly good for how relatively cheap they are. What is more important is making certain that the ground glass is at precisely the plane where it belongs. If this can be attained, then the variations in film holders and thicknesses of film and curvature due to different humidity, etc., will ususally fall within the +/- .007". If the gg is shallow by a few thousandths, then film holders that are on the deep end of the specified tolerance will actually hold the film further back from the focus plane than would be acceptable for the required sharpness. If the gg is too deep, than shallow film holders will cause a similar problem in the other direction. Cameras like Linhofs and Sinars are very precisely checked at the factory for ground glass depth. I know the Linhofs have micro adjustable pads for changing the depth. Wooden cameras can be pretty accurate, but generally offer no means for adjustment of gg depth other than shims (which can only deepen the dimension). The biggest culprit for gg/film plane alignment is the sometimes arbitrary addition of Fresnel brightening screens between the gg and the lens or the equally problematic removal of same when they were in fact "designed" into the camera. If you are interested, I'll be happy to email a copy of an article I authored on this topic for ViewCamera magazine. Or perhaps you have the Nov/Dec '97 issue in which it appeared. Small or large aperture, whatever your preference, the only way you'll be certain to get on film what you see on the gg is proper gg placement. Only filmholders that are warped, worn out or damaged are going to cause big problems. Still, it is a good idea to inspect them and also to number them so you can observe "trends" over time that might uncover a problem.

[scott_fleming1]

You ARE wierd.

 

And wonderful too. I think St Ansel would have wanted some of your prints.

 

Might I ask. What did you shoot dog ... in lynchberg '02 with? Camera I mean.

 

Regards,

Scott ...

River Run Ranch ...

Texas

[squareframe]

> "as long as the film plane coincides with the ground-glass plane." - But that's the very issue, isn't it Daniel?

 

I interpreted Mark's question to be addressing film flatness and not registration issues. If I had a worry, it would be orthogonal alignment - corner to corner. even my Technikardan seems to flop around with little guarantee of accurate and repeatable positioning with placement/removal of the film holders. since I always use full-aperture and most likely a tilted back, corner sharpness is nary a worry.

[mark_tucker2]

Daniel,

 

My concern was more about these films "bowing" or "buckling"

somehow when they're in the holders. I wasn't much thinking

about the holders themselves being wrong. It almost makes you

want to choose a film that's thick and heavy, to possibly reduce

the bow.

 

But again, from all these responses, it doesn't seem like it's a

big deal. I'm newly back to 4x5, after years of 220, so all these

issues of LF are flooding back to me.

 

Was your comment about the spherical holder a joke? I

remember taking type 55 negatives and wadding them up and

then printing them when they unfolded, back in the wet darkroom

days. It made for some beautiful effects. Seriously.

 

I shot a picture for myself this afternoon with T55. The whole box

was ruined; the developer pod was defective in all of them but

one or two sheets, and left a giant void down the center of the

frame. Luckily I got one keeper frame. Made me reconsider the

QuickLoads, but it was weird today, looking at B&H choices in

both Fuji and Kodak ready/quick loads. Fuji showed NO b/w; and

Kodak only TMAX 100; no 400. And with Polaroids' reputation on

the rocks, makes me wonder about the future of BW LF.

 

All coffeed up and scanning,

 

MT

[triblett_lungre_thurd]

ellis,

 

2.8 planars... prolly 100mm. judging by marks' wonderful online stuff, he prolly doesn't have to worry about them covering @ infinity.

 

just a guess,

 

me

 

p.s. what's the actual factual dimens of a 545 type 55 anyhow? do they make type 55 for the 405?

[mark_tucker2]

"p.s. what's the actual factual dimens of a 545 type 55 anyhow?

do they make type 55 for the 405?"

...

 

No, the 405 is only for 665; I just bought one on ebay last night.

They GREAT for shooting 665 in a 4x5.

 

Type 55 is slightly larger than normal sheet film. Enough to be a

hassle to scan. But the tonal range more than makes up for it.

And the immediacy.

 

Ellis, the lens is a Komura 152mm f2.8 lens, and I got it years

ago from Glenn Evans in Chicago:

 

http://www.glennview.com

 

And before you go calling him, I'm first in line for anything he gets

that's faster than f4. He must show me everything he sells first,

or else...

 

There's that f2 125 on ebay right now, but who know what stat

camera it came out of. and It's up to nine hundred dollars, and

it's only in a barrel! Please...

 

MT

[david_goldfarb]

"Made me reconsider the QuickLoads, but it was weird today, looking at B&H choices in both Fuji and Kodak ready/quick loads. Fuji showed NO b/w; and Kodak only TMAX 100; no 400. And with Polaroids' reputation on the rocks, makes me wonder about the future of BW LF."

 

I think the marketing theory here is that anyone curmudgeonly enough to be shooting B&W in this day and age is stubborn enough to load his own damn holders and most likely has a darkroom to do it in.

[mark_tucker2]

<I>"I think the marketing theory here is that anyone

curmudgeonly enough to be shooting B&W in this day and age is

stubborn enough to load his own damn holders and most likely

has a darkroom to do it in."</i><P>

 

David,

 

Are we all dinosaurs already? I'm not ready to be put out to

pasture yet. It's like we're just going along, living our lives like

normal, with our own standards and our own love of

photography, and then, Whoosh!, here comes digital, and pulls

the rug out from under us all, and we get up one day, and

Everything is suddenly different.<P>

 

It really *did* seem like it happened overnight. (I went to two

large camera stores yesterday to buy a spanner wrench, and

both of them looked at me like I had three eyes, when I asked for

that tool). At that point, it *did* hit me; "Holy shit, everything *IS*

different; nobody even knows what a spanner wrench is, let

alone do they stock it any more." I sort of slinked out of the store,

feeling old and hunchbacked, while all the Christmas shoppers

stood three deep in line for the latest greatest digital snapper,

wiping the drool from their mouths.<P>

 

I looked in the rear view mirror on the way out of the parking lot,

and I swear to you, my beard really *was* a bit more grey...<P>

 

-MT<BR>

(sitting here scratching myself)

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<p><u>Film holder depth:</u></p>

<p>According to the ANSI standard it should be 5 mm for 4X5 +/-0.178 mm and 6.6 mm +/-0.406 mm. Relative to Sinar's allowable deviations for their precision film holders, ANSI's allowable deviations are the size of the Bay Bridge and compliance with ANSI hardly a sign of precision. </p>

<p>The 5 mm depth for the film holder <b><u>defacto</u></b> establishes a depth for the ground glass, which should be 5.00 mm -film thickness. Film thickness varies for positive and negative films, by relatively large dimensions (0.001"), thus if you want to have accurate registration and you use both film types, your camera should be equipped with two ground glass frames one for each. </p>

<p><b><u>The Fresnel</u></b> should be on the side of the GG facing the viewer. This allows a quick check on the calibration of the GG without having to remove it.</p>

<p>By the way, if you intend using depth micrometers for measuring FHs with <b>spring loaded septums</b>, save your time, it is practically impossible since the septum does not offer enough resistance to the probe to indicate contact and oppose the pressure of the probe, even if you use the digital micrometers which have much greater sensitivity because those require more turns for unit of linear travel of the probe. It may be possible wit electronic instrumentation to refine the depth micrometer measuring sensitivity but better yet, the use of non-contact devices such as lasers should yield by far the best results, -even with spring-loaded septums.</p>

<p>Calibrating and adjusting the GG with the degree of accuracy which Sinar guarantees for their film holders is not difficult, but measuring FH depth is not as easy as it seems as you quickly discover if you apply statistics to check your measurements. </p>

<p><u><b>Film Holders</b></u>: In one batch of Fidelity film holders tested recently, 5 of 6 yielded the most consistent and accurate depth against ANSI, well below the wide variations allowable under ANSI. Compared to those, TOYO holders scored second, with variations about 1/2 ANSI. Lisco holders in my measurements were most within the ANSI spec but many were near the limits of the spec's allowable deviations. </p>

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[jerry2]

Mark, you wrote....Are we talking that say, 2mm of play would have a very noticeable effect on focus? Or would it be more?

 

Using a desireable circle of confusion of .033 mm, the film must be within .0666 mm either in front of, or behind the the plane of sharp focus at the film plane. This is impossible to acheive with standard film holders. Insert a piece of film and see for yourself... 4x5 film is not flat, it buckles in its own special ways. This is one of the reasons LF lenses are optimized at f11 - f32. Anything less would be counter productive. Of course, one method to reduce this part of the problem is using a vacum-back film holder to acheive perfect film flatness.

 

However, if the lens your shooting with is many stops removed from its design MTF range, your limiting factor most likely will be your lenses, not the film flatness. Both issues working against you can be disasterous. Of course I am not making claims about the lens you are using, as I am not familar with it.

 

As many posters mentioned above, all these issues are muted if your gg and film alignment is not highly accurate. Mamiya USA will check this with a laser and adjust it accordingly.

 

I am sure you are familar with the DOF of shooting at f2. Using the same cc as above, focussing a 150mm lens at 15 ft, produces a DOF of 5 inches. (2.5" in front of and 2.5" behind the plane of sharp focus)

 

These are some very tough requirements for shooting 4x5...but I guess if your trying to exploit the full sharpness capability of LF, it would take a very unique lens, a vacum back, a laser verified gg / film alignment and a subject which is either very far away, or extremely flat. Otherwise, IMHO, shooting a good MF camera would produce superior results, even after the 2x enlargement required to compare to 4x5. MF cameras have lenses designed to be shot very wide open, excellent film flatness (specially in cameras like the Mamiay 7), vs. sheet film and excellent gg/film alignment (on most newer MF cameras)

[robert_a._zeichner1]

"I am sure you are familar with the DOF of shooting at f2. Using the same cc as above, focussing a 150mm lens at 15 ft, produces a DOF

of 5 inches. (2.5" in front of and 2.5" behind the plane of sharp focus)"

 

If by DOF you are referring to Depth of Field, may I point out that this zone is twice as deep behind the object plane as it is in front of that plane. Only with certain very special lens designs does this change.

 

The focus plane, by the way, is where subjects that lie on the object plane are supposed to come into sharp focus at the film surface. There is a zone of acceptable sharpness called Depth of Focus which occurs here. This zone, unlike the Depth of Field zone is of equal distance in front of and behind the focus plane. How deep that zone is, is determined by the circle of confusion dimension that is settled upon based on things like how much the negative will be enlarged. If only making contact prints, a larger circle of confusion and hence deeper zone (depth) of focus would be tolerable. Makes sense when you look at the ANSI specs for an 8x10 film holder which are .260" +/- .016".

 

Regardless of how much or little depth of field there is at a given aperture and with a given focal length, the arrived at circle of confusion and the associated depth of focus are really independent in that only subjects lying on the object plane (the plane on which the lens is focused) are ever exactly in focus at the focus plane. This is of course in a perfect world where film holders, ground glasses, human vision and optics are exact.

 

Depth of field can never compensate for groundglass misalignment! It can only serve to obscure it. Some objects may appear to be perfectly focused, even with the gg way off, but they most assuredly will not be the objects on which the photographer focused his or her lens! Unless ground glass/film plane coincidence is reliably close, you'll never be able to fully gain the advantages of depth of field when trying to bring everything into acceptably sharp focus. If you are shooting at f2, this just means you'll notice the error on film more readily as you will not have much depth of field to mask the problem!

[photo_color]

I have tried several 4x5 and 8x10 cameras. With 4x5 I've used various sheet film holders and the Fuji Quickload holder. If you are doing contact printing or very low enlargements, like up to 11x14 from 4x5, then none of this matter too much. Otherwise, I have found that the most important factor (at least for me) was the alignment of the front and rear camera standards. It's not that easy to get a wood field camera to be in precise alignment - you need to be carefull. I had better luck with metal cameras - like the Arca Swiss monorail, or Toyo AII. When you insert the film holder you need to make sure that the rear standard comes back to exactly where it was when you focused, and the camera doesn't rotate on the tripod head. And, of course you have to focus carefully with enough magnification so that you really know what's in exact focus and what's not quite. And focus check all areas of the image. As far as holders go, as you've seen from other postings here, they do vary, even within brands. I thought Toyo holders may be the best, but recently it seems they changed the way they manufacture them and seem to be not as high quality. Taking into account cost, I'd probably get the plain vanilla Fidelity holders (probably as good as Toyo and cheaper; and one person on this forum found the Fidelity to be better on average than the Toyo).

[jerry2]

Robert, thanks for the correction of focus plane at the film plane.... I did not catch my error on my proofread.... also, you wrote...

 

If by DOF you are referring to Depth of Field, may I point out that this zone is twice as deep behind the object plane as it is in front of that plane. Only with certain very special lens designs does this change

 

Here is the standard DOF calcs for a 15 ft focus distance using the variables above, 150 focal length, f2, .0333 mm cc, 15ft focus distance....

 

177.6 inches near DOF to maintain desired cc

180.0 Inches, point of exact focus.

182.5 inches, far DOF to maintain desired cc

 

This represents 2.5" in front of point of exact focus and 2.4" behind the point of exact focus. This fits the half in front, half behind desciption, vs. "this zone is twice as deep behind the object plane as it is in front of that plane"

 

Were you refering to the Hyperfocal distance where this occurs? I am curious as to your findings.