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olwick
4-Aug-2010, 04:38
Hi,

Is there any one brand/type of 4x5 film holder that holds the film more perfectly flat than others?

I was reading Barry Thornton's Edge of Darkness, which prompted this question. It makes sense that there would have to be a small amount of "slop" in the film plane of holders due to having to be able to slide the film in and out, which he says can affect consistent sharpness across the plane.

Thanks,

Mark

Daniel Stone
4-Aug-2010, 04:57
I haven't had a problem so far with 4x5 or 8x10 holders, no matter the brand. But then again, I DON'T shoot wide-open most of the time.

for 4x5's I have plastic holders, and 8x10 holders are the kodak/agfa wooden ones. Probably 50yrs old +, but still work like new.

-Dan

Bill_1856
4-Aug-2010, 05:08
There are vacuum holders out there, used mainly for scientific work before digital took over, but basically I think you'd be swatting at mosquitoes.

memorris
4-Aug-2010, 06:04
Some investigation by a local photographer a couple of years ago had Toyo as the most consistent in position and flatness.

Brian Stein
4-Aug-2010, 06:15
Yes there will be some bow in the film, the bow being larger the larger the film sheet. There is no way apart from a vacuum back or similar or moving to glass plates (I recall someone using wedges to jam the sheet of an ULF film into a home made back) to overcome this. Against this is the general requirement for less tight tolerances the bigger the film because of lower enlargement factors, and the tendency to use smaller apertures.
Practically, having a bunch of holders from different makers and different eras I cant say that there is any detectable difference in the "slop" in the film, nor in the sharpness of the end result between them in the sizes I use (45 57).

Steve Hamley
4-Aug-2010, 06:43
I've found there's very little if any bow in 7 mil film in 4x5 holders. Of the 4x5 holders, Riteways I've measured have less space between the film rails and the platen, so there's less space for the film to move back and forth. I posted the measurements in a thread a while back.

On 8x10, I like Toyos because they have extra "fingers" in the end of the holder that the film slides under.

Cheers, Steve

Steve Gledhill
4-Aug-2010, 06:46
As far as I can tell my film is always held flat in my Lisco 5x4 holders - EXCEPT - there is one set of conditions when the film may not be flat - see this post (http://www.largeformatphotography.info/forum/showpost.php?p=546794&postcount=20) from a while back about photography in cold weather. My post was really about film moving laterally in the holder but I guess it could also 'pop' from flat to not flat with an abrupt temperature change.

Brian Ellis
4-Aug-2010, 08:01
Somebody published results of an exhaustive test of about 10 different film holders in View Camera magazine or maybe it was Photo Techniques some years ago. None held the film perfectly flat. IIRC the winner actually was an older wood holder and I think a Grafmatic did pretty well too. But none of them were very close to perfect.

This is one of those things that always comes to mind when I hear or read of people getting excited because the front standard and rear standard on their cameras are out of parallel by .2mm or that their bubble level is off by .1mm. These things we use aren't precisions instruments and getting worked up over some insignificant deviation from perfection is a waste of time and energy IMHO.

SamReeves
4-Aug-2010, 08:28
Yea, I don't think there is too much to worry about flatness in your average plastic holder. I've used the Lisco's for 10 years, and haven't had any issues. It's all about the loading!

Jack Dahlgren
4-Aug-2010, 08:33
If I look at all the holders I have that have light leaks, they are all fidelity/lisco. I don't like the plastic holders for that reason. But for film flatness, you probably won't see much difference between holders (other than normal variation) unless you use a vacuum back or glass plates. There are some Linhof holders which clamp down on the film, but I hear that they are troublesome to use and expensive. I have not tried them.

Do you currently have a problem with film flatness that you are trying to solve? Or is this "just in case"?

numnutz
4-Aug-2010, 08:38
you can always try a vacuum back like this one:

http://www.deadbread.com/crumbs/vac.html

nn :)

olwick
4-Aug-2010, 09:43
Do you currently have a problem with film flatness that you are trying to solve? Or is this "just in case"?

Nope, I just read that in the book I mentioned - Mr. Thornton was very "in depth" about sharpness. He used it as his signature style, really. I was just trying to see what the real world experience was.

Thanks for all the info and tips!

Mark

ic-racer
4-Aug-2010, 10:32
The problem I have encounterd is movement of the film during exposure, which is independent of aperture setting and DOF etc.

Of the few cases I have encoundered, and from reading posts of others, my current thought are that it is related to the following:

Length of exposure
Forward tilt of the rear standard


The negatives shows a definite double image with a separation of a few fractions of a millimeter. The effect was usually at the top of the film (bottom of the scene). This is distinctively different from wobble in the rear standard which produces a blur.

I suspect this film movement is caused by small changes in temperature, humidity and the effects of gravity on the film rather than any factor relating specifically to the film holder.

Drew Wiley
4-Aug-2010, 10:58
It is a scientific fact that conventional filmholders do not hold film perfectly flat.
Whether this presents a practical problem or not just depends upon your standards.
Some film (especially acetate base) is more flexible and sloppy than other film stock.
Pointing a camera downward potentially accentuates this problem. Another factor is
the degree of intended enlargement. For example, when I shoot 8x10 color film for enlargement to 30x40 I always use specially constructed adhesive filmholders which
do keep the film flat. Failure to do otherwise would be conspicuous in the final print at
this degree of magnification. On the other hand, I rarely do this with black and white
8x10 film because the films I choose are fairly stiff, and I enlarge them only up to
20x24. Since 4x5 is a much smaller film size, it seems to bow considerably less, and
so far I have had no incentive to use specialized holders. In the lab for critical work,
like making precision dupes or internegs, I always use a precise vacuum filmholder.
At one time Sinar made a precision pressure-plate filmholder for 4x5, but it cost over
$500, accepted only one exposure at a time, and never really worked as well as a
vacuum holder. In the old days, especially for astrophotography, the answer was
glass plates.

Jim Noel
4-Aug-2010, 11:33
Somebody published results of an exhaustive test of about 10 different film holders in View Camera magazine or maybe it was Photo Techniques some years ago. None held the film perfectly flat. IIRC the winner actually was an older wood holder and I think a Grafmatic did pretty well too. But none of them were very close to perfect.

This is one of those things that always comes to mind when I hear or read of people getting excited because the front standard and rear standard on their cameras are out of parallel by .2mm or that their bubble level is off by .1mm. These things we use aren't precisions instruments and getting worked up over some insignificant deviation from perfection is a waste of time and energy IMHO.

I remember that article. The old wooden Graflex holders with metal edges at the slide end were the best and Grafmatics were so close it could be called a tie. My judging of the results shown in the carts is that the newer the holders, the sloppier. Personally I don't use any plastic holders except in rare cases.

Sal Santamaura
4-Aug-2010, 11:40
It pays to visit the home page:

http://www.largeformatphotography.info/articles/englander-holders.1.gif

http://www.largeformatphotography.info/articles/englander-holders.2.gif

http://www.largeformatphotography.info/articles/englander-holders.3.gif

http://www.largeformatphotography.info/articles/englander-holders.4.gif

Jack Dahlgren
4-Aug-2010, 12:21
It pays to visit the home page:

http://www.largeformatphotography.info/articles/englander-holders.1.gif

http://www.largeformatphotography.info/articles/englander-holders.2.gif

http://www.largeformatphotography.info/articles/englander-holders.3.gif

http://www.largeformatphotography.info/articles/englander-holders.4.gif

From that all I can tell is that he tested one grafmatic and one riteway.

I think that sample variation across a number of used film holders from the same manufacturer is likely to be larger than the differences measured between the two samples that he used.

Unfortunately I don't care enough to check a larger number of film holders so I'll never know for sure.

Rick Moore
4-Aug-2010, 15:19
Didn't Sinar used to sell a holder that used some type of double-sided adhesive on the septum to hold the film flat?

In a post on another web site, Bob Salomon mentions that Linhof made single-sheet holders that held the film flatter than regular holders, although they only used their pressure plate for glass plates, not film.


--
Rick

BradS
4-Aug-2010, 15:42
From that all I can tell is that he tested one grafmatic and one riteway.

I think that sample variation across a number of used film holders from the same manufacturer is likely to be larger than the differences measured between the two samples that he used.

Unfortunately I don't care enough to check a larger number of film holders so I'll never know for sure.

My sentiments exactly....sample size of one is meaningless. We have no idea how repeatable his measurements are. We have no idea what the variation within brand is nor do we know what the variation from brand to brand is...the published numbers are completely meaningless.

jesse1996
5-Aug-2016, 19:58
http://www.cloudynights.com/documents/large.pdf

Jim Jones
5-Aug-2016, 20:38
Even if the film is perfectly flat, its distance from the face of the film holder can vary 0.022 inches or about 0.56mm and still remain within ANSI specs. With fast lenses, this can make a noticeable difference in sharpness. Careful measuring and selecting film holders can reduce this.