Please measure your 11x14 Deardorff 'T' distance

[Tin Can]

As some may know I am setting up a Deardorff SC11 studio 11x14. I have just checked my 11x14 Deardorff OE and very old 11x14 back. 'T" on mine is 0.240"

I would like to know what other Deardorff's measure, both Field and Studio 11x14's as I may need to make major mods to get within ANSI 'T' of 0.332"

Some suggest custom holders, others suggest new GG frame and I suggest shimming.

Thanks for any info on 'T' measurements!

[Harold_4074]

Hmmm. I thought that I had read, somewhere, that the ANSI dimension was nominally 0.315 in (i.e., 8mm) with tolerance of +/- 0.005.

In any case, I'll try to remember to check mine this evening and let you know what I find out.

[Tin Can]

Thanks Harold,

There are some different sources.

http://www.filmholders.com/filmho1.html

http://home.earthlink.net/~eahoo/page8/filmhold.html

http://ssfilmholders.com/?page=dimensions

http://photo.net/large-format-photography-forum/00437g

The more I research, the more I become confused.

I have made up my mind as to what I am doing, but I am going to stick my head back into the sand to avoid creating any controversy. Hence, I will make no conclusions here or by PM.

I am still very interested in measured T on any camera now!

Hmmm. I thought that I had read, somewhere, that the ANSI dimension was nominally 0.315 in (i.e., 8mm) with tolerance of +/- 0.005.

In any case, I'll try to remember to check mine this evening and let you know what I find out.

[Harold_4074]

Okay, I measured my (restored) Deardorff SC11 back, and got a reasonably repeatable (all four corners) measurement of about 0.270 inches. On the other hand, I measured one of the NOS Fidelity Medical holders that I have, and got 0.315 inches, dead-on according to the 1998 ANSI spec.

I'm willing to believe that the Deardorff is short because of a combination of wear and refinishing; as I would expect, the top corners seem to be worn a bit more than the bottoms. The kind of pictures that I make wouldn't be likely to suffer from an error of 0.040, but I may just have to set up a test one of these days and see if it is detectable--just focus as usual, clamp a block behind the rear standard, and make the exposure with an 0.040 shim to shift the back forward by that much. It if really matters, it won't be difficult to permanently shim out the groundglass holder to meet spec.

[Tin Can]

Thanks Harold, it seems we are the only 2 using a S11 on this forum.

Kinda sad, more are not set-up.

I am working on a solution to my issue, or rather I am seeking help with my issue.

Okay, I measured my (restored) Deardorff SC11 back, and got a reasonably repeatable (all four corners) measurement of about 0.270 inches. On the other hand, I measured one of the NOS Fidelity Medical holders that I have, and got 0.315 inches, dead-on according to the 1998 ANSI spec.

I'm willing to believe that the Deardorff is short because of a combination of wear and refinishing; as I would expect, the top corners seem to be worn a bit more than the bottoms. The kind of pictures that I make wouldn't be likely to suffer from an error of 0.040, but I may just have to set up a test one of these days and see if it is detectable--just focus as usual, clamp a block behind the rear standard, and make the exposure with an 0.040 shim to shift the back forward by that much. It if really matters, it won't be difficult to permanently shim out the groundglass holder to meet spec.

[Harold_4074]

I guess that the seriousness of these dimensional discrepancies really depends on the use that you put the camera to. For product photography, your 0.240" setback and my 0.315" holder might be problematic; for a portrait, both eye catchlights are probably not going to the in the exact object plane at the same time anyway, and those (both?) of us who use these beasts with 11x14 backs don't, as a rule, enlarge the negatives.

I didn't pull the back apart to look for wear on the front face of the groundglass frame, but I think that it registers on "pads" at the corners, which would naturally wear fastest from holder insertion and removal. And, of course, be the easiest to repair

For what it is worth, the ANSI spec for the height of the slot the film goes into seems to be 0.012, about twice the thickness of 1950s film stock; this should give some idea of the seriousness of an error of a few thousandths of an inch.

[Tin Can]

Yes, I am aware of the 'slop' in focus allowed with portraits and who shoots product with these? Still life perhaps? But I am pretty sure, even blind Randy, finds 1/8" of focal plane difference pretty bad for my crude efforts. I am going to correct the problem and get holders to match the correction.

Now back to raising holder cash!

[RichardRitter]

I keep a running record of the "T" dim on most of the ULF camera I work on. I have recorded 5 different "T" 's on 11 x 14 cameras.

[mdarnton]

If I were going to do it, I'd buy the holders first, then adjust the ground glass to the holders.

[Tin Can]

Do you care to share the different T distances?

I know this gets sticky real quickly and perhaps silence is best.

I keep a running record of the "T" dim on most of the ULF camera I work on. I have recorded 5 different "T" 's on 11 x 14 cameras.