erie_patsellis

probably a little late, but if you depress the two silver bars and slide the ground glass towards the end that you would load the film holder into, it will slide off, no Allen bolts required

that also explains the sensor problems in developing newer lenses for LF. the other deals with crop factor, another overlooked fact in comparing digital lenses to analogue. focal length equivalents have more to do with image coverage and the size of the sensor regardless of media.

 

Did you see there is a 4x5 sensor coming? imagine the size of those files and the machinery you'll need to open them?

 

for now the scanning back makes sense but that's rather slow for most applications. when I first started thinking of scanning backs, I thought theyd do it more like focal plane shutters with the narrow sensor running by at 1/1000s. I once tried holding my scanner to the back of my 8x10 (digital dawn) but I never really did enough experimenting.

Paul,

after trying several backs on LF, that's the same conclusion I came to. The sensel size on the Dicomed Field Pro I have is in the sweet spot for the lenses I have, and it works wonders on the RB as well, though only a 6kx6k image @ 7x7 cm capture

erie

<p>I'm all for repairing as much as you can yourself, however, if you reference the attached jpg of the service manual, you'll note that reassembly needs to be within .03mm of the reference. Not something most people have the tools to measure, much less have the required jigs to do so.</p>

<p>A misadjusted body will still work, though typically most will blame focusing errors on a bad lens, or misaligned screen. There are many, many easily done repairs, including lens shutters (even in a hassy lens) and lens disassembly/element cleaning if you use care and are attentive to details. Aligning a Hasselblad body, however, isn't one of them. I've done it, when I had access to the proper jigs and tools. Even having the proper jigs and tools it's tricky to get within tolerances.<img src="http://farm8.staticflickr.com/7251/7646860270_b024d680ec_b.jpg" alt="" width="680" height="582" /></p>

<p>Martin, what others may have failed to communicate is that:<br>

The Hasselblad cameras require several specialized tools, as well as a very specific jig (that can't readily be improvised) in order to set the film to flange distance after reassembly.<br>

Failure to use this jig (and have the knowledge and experience to do it properly) results in a camera that will never focus correctly. It is not a setting that can be marked and the body returned to, nor can it be "winged".<br>

The other major issue is that the cocking assembly requires a jig to set the proper actuation at various angles. Some can do it by eye, but without the jig it may work on one lens and not the other, etc.</p>

<p>I'm fairly mechanically inclined, and have all the repair manuals and tools as well, but I won't even attempt a hassy body after reading through the manual several times. I'd be happy to send you the pdf files, should you need them.</p>

<p>Or...... you could search and probably find the official Hasselblad repair manual pdf's.</p>

<p>Either way, the nylon stopper needs replacing, and the back could probably use a good CLA. Unless you've done a few, it's a job best left to people that know what they're doing.</p>

<p>Jim, if your D100 wants to come out of retirement, let me know, I'm looking for a few D100's for a project I'm working on.</p>

<p>erie</p>

<p>And Luis, Larry is as deserving as they come.</p>

<p>They are usually stocked. Check back with us when you get the prices, if the prices are anything like here in the US, one can get awfully creative for what those levels cost.</p>

<p>Michael, your example is good, except for one little detail. Aperture is defined as the focal length divided by the entrance pupil, not raw aperture diameter. The difference is that using the raw diameter ignores the magnification by the front element. It could very well be that the aperture is correct as-is, other than the obvious 6.3 maximum aperture. The best way to determine the entrance pupil diamter is by holding the lens at arms length and measuring the apparent aperture size with a caliper. This will get you in the ballpark, depending on how accurately you measure the diamter. Typically, a plasmat magnifies the apparent aperture size, and a reverse Dagor (Angulon, Grandagon) reduce the apparent size.</p>

<p>Spacing on a plasmat design lens, such as the Symmar and Sironar family, isn't very critical. I have tested mine with as much as 2.5mm additional between the groups (in an attempt to increase spherical abberations) and they performed reasonably well. Angulon, Distagon and Grandagons can be very fussy about spacing, so much so that I check every lens of that general design (reverse Dagor) when I buy one.</p>

<p>I'll post them in case you haven't:<br>

this lens<br>

<img src="http://i144.photobucket.com/albums/r181/epatsellis/DSCF7412.jpg" alt="" /></p>

<p>took this picture (on 8x10)<br>

<img src="http://i144.photobucket.com/albums/r181/epatsellis/stream.jpg" alt="" /><br>

Other than missing the corner being clipped, it's quite a stunningly sharp image until the last 3/4" or so of image circle, but that has nothing to do with the chip in it. It is a result of shooting at f11 instead of f16 or smaller, as it was rapidly getting dark and even at f11, the exposure was close to 30 seconds. I'd go so far as to mail you the negative for you to evaluate should you wish.</p>

<p>Clean the componon up well, and you'll have no issues.</p>

<p>Paul, your first image show a tremendous amount of either dirt or lime scale (possibly the lens got wet as some point??). Have you removed the group and cleaned it? I suspect that once clean, you'd likely not have any issues.</p>

<p>I don't see any cement failures, but you should be aware that Schneider used UV curing adhesives, not balsam, and heating it won't have any positive effect, but likely some negative. Cement separation in these adhesives takes on a snowflake pattern, I can post pictures of what it looks like as I have a couple of separations in my 360 Componon (and they have no effect on taking).</p>

<p>I'm sure I've posted and you have seen the pictures of the 210 Componon I had in a shutter that had a good sized (around 1/4"x3/8") chunk out of it and images were just fine.</p>

<p>Paul,<br>

In my opinion (FWIW), much ado about nothing. I use lenses of all types with/without multicoating, lenses made with and without edge blackening, Schneideritis or not, etc. I can bet if you shot two images, one with the lens and one with an identical lens without you would be hard pressed to see, much less measure any substantive differences. There are plenty of things to be concerned about, but that's not one of them.</p>

<p>And yes, I've done the very same test I'm suggesting, there is such a trivial difference that exposure errors, or if this is a digital hybrid the effects of post processing, will swamp the effect by orders of magnitude. There are other things to be obsessed with, but this isn't one of them.</p>

<p>3x3 glass wrattens are two pieces of filter glass, with a gelatin filter sandwiched between, most of the the ones I have are around 3 to 4mm thick.<br>

Jukka, unless you can get them for free, I'd not bother myself.</p>

<p>When I mention the slight difference, I am comparing scans made with a Polaroid Sprintscan 4000+ to the same image "scanned" with a Kodak SLR/N (shot at base ISO in RAW, no NR and conversion in Photodesk). As to the previous comments about the Kodak and NR induced artifacts, they are capable of stunning images, with the right person. Give me any DSLR and I bet I can make bad images from it in a matter of minutes. For those that are willing to use it in it's intended role (as a studio camera, with controlled lighting), it's just as capable as any other.<br>

From time to time, I will use a Leaf Micro Lumina F-mount scanning camera, the scans with it are as good (for my needs) as any scanned 35mm image I have used, as long as there aren't Dmax issues to contend with. It's not instant capture nor a DSLR and I won't muddy the waters with that comparison.<br>

The majority of my personal film work is C41 based, so Dmax isn't an issue. I process and print all my own images, with occasional scanning for online viewing or to share an image. Neither scanning method compares to optical printing done properly however. What I don't understand is this overwhelming desire to convince others that "they're wrong, you're right and just get over it." I have better things to do than compare minutiae between scan A and scan B. In my opinion, if quality were that important, you'd be using much larger negatives and cut the B.S. out totally. You have to try really bad to get a bad scan from a 4x5 negative or tranny. This reminds me too much of the "Leicanistas" who seem to thing sharpness is the overall indicator to image quality and will spend thousands just to get a 5% increase in perceived sharpness. Is it really that important that you get every last bit of potential detail out of a negative?</p>

<p>One of the projects I am involved in is (slowly!) digitising an archive of approximately 5,000 images for the local historical society, all done out of my own pocket, I do a box here and there as I have time. Is it really that important to wring every last bit out of an 8x10 glass plate? Doubtful in this application (like the one in the article referenced, btw) simply having an accounting and a general idea of what the image is of is more important. Anything determined to be important has a duplicate negative made of it and a contact print made. Should they want murals made, I can just as easily rescan an image as needed, no need for such demanding resolution for what amounts to a catalog of images.</p>

<p>I suppose if you need to justify in your own mind that the pile of money you spent was an "investment", by all means continue on, but I have far better things to do than continue in such pedantic drivel.</p>