Any experience with the Sinar 8 X 10 adhesive film holders, vis a vis claims of sharper image, flatter film, etc.? I'm especially interested in situations where one is shooting down (product shot, architecture, whatever). In these situations, film will indeed bow forward, often sufficiently to throw it quite noticeably out of focus, even in modern, newly-bought Toyo holders.

Appreciate your feedback, Nathan

-- Nathan Congdon (ncongdon@jhmi.edu), November 17, 2000

Answers

Interestingly, in the days of glass plates, this was thought through a bit more. You have single-plate holders with butterfly pressure backs (split or unfied) just like on the contact print frames we are all familiar with. And at a recent camera show, I saw double-sided plate holders with a lever mechanism that would put pressure on the glass plate before drawing the dark slide. Seems like more concepts would have hit the marketplace at the heyday of sheet film photography.

-- David Stein (DFStein@aol.com), November 17, 2000.

Natahan, I also was pursuing this same avenue... Those Sinar holders seem great, but they are also like $600 each! I bought some double sided tape and placed it in my Toyo holders, then slid the film in the holders....if you are careful and pateint the film will jiggle in, not easily though.... then once in, I press the film, using darkroom gloves of course, against the tape...it holds well, but then getting the film out is a bit challenging... but its cheap, can be done with any holder and serves its purpose. I too am amazed that no one has comeout with some type of glass plate device as described above? I guess 8x10 has become a very very tiny market!

I also read the Hoffman view camera in NY has a 8x10 vacum back holder, I am not sure of the specifics on it.

-- Bill Glickman (bglick@pclv.com), November 18, 2000.

Even at $290 a piece (you know where) I still don't think that they are worth the money. I've done many product shots where the 8X10 camera was in a vertical position and have never noticed a resulting un-sharpness.

-- William Levitt (light-zone@operamail.com), November 18, 2000.

I would think they would be most useful for multiple exposures, where you would need to remove the filmholder to set up different parts of the shot and recompose, replacing the holder very precisely without the film jiggling inside the holder.

That said, is the adhesive in the adhesive back a product that isn't used for any other purpose? I've heard of some people spraying darkroom easels with repositionable adhesive as a cheap alternative to a vacuum back. It doesn't seem like it would be too hard to modify a regular holder (shave off the film groove so the film can be dropped in) or maybe a Graflex pressure-type holder for this purpose.

-- David Goldfarb (dgoldfarb@barnard.edu), November 18, 2000.

I understand that Sinar does sell the adhesive to be reapplied to the holder after what is on their gets dusty or damaged. Maybe you can buy some of it and try it on a holder & see how that works?

-- Dan Smith (shooter@brigham.net), November 18, 2000.

I have used double sided tape on some occasions, when I was concerned that film would buldge during a ten minute exposure. Loading the holder was easy. On the other hand, unloading it without damaging the film was tricky. I had to apply some force, and this resulted in the film getting slighly bent. David, what method did you use to unload ?

-- Q.-Tuan Luong (qtl@ai.sri.com), November 18, 2000.

I haven't tried it yet. I'm just contemplating, and the unloading problem is the reason I'm thinking it might be worth modifying a filmholder for the purpose--the thought being that if I were to remove the film groove so that the sheet would just into place rather than sliding, I could just peel it off.

-- David Goldfarb (dgoldfarb@barnard.edu), November 18, 2000.

That last line should be "would just press into place."

-- David Goldfarb (dgoldfarb@barnard.edu), November 18, 2000.

How about making a piece of plexiglass with the sides grooved to match fit in the side rails as film does. Then tape the film to the plexiglass with double sided tape! I think this would simplify the process vs. taping the film to the holder. I agree with the above poster, if you put the tape on too tight it is hard to get the film out. After a few tries, I learned to put 4 - 5 small 1" pieces around...just enough to stop the buckle, but not enough to cause problems when removing the film...

-- Bill Glickman (bglick@pclv.com), November 18, 2000.

Nathan,

If you are shooting a product shot straight down, you are probably in the 1:1 range. Next time you are set up in this manner, try racking the back standard in and out and notice how far it has to move to affect even a slight change in focus.

Someone can explain the physics of depth of focus vs. depth of field better than I but suffice to say that you would probably not notice the effect of film sag in this situation.

Infinity focus, on the other hand, is a problem, especially in the field where temp. changes are the norm. The best (read cheapest) way I've found to deal with this is a small piece of double stick tape in the center of the holder. And like a previous post suggests You need to rub it with your finger a bit to make sure that it is not too agressive then put a mark on the slide directly above so that all you need to do is push gently on the slide to tack it just before shooting. If you store the film in a box, before processing, be sure to place the sheets face to face. This prevents any residual adhesive from pulling off a chunk of emulsion.

If you are working in the studio, or in a controlled environment, you really don't have to worry about any of this. Modern film is coated on the concave side of the curl and as a result, tends to seat itself.

Better ways to spend money. bw

-- Bruce Wehman (brucewehman@home.com), November 19, 2000.

Thanks to everyone for the creative cost-saving suggestions! Sorry I didn't reply to each of you personally due to the large volume of responses.

Nathan

-- Nathan Congdon (ncongdon@jhmi.edu), November 19, 2000.

After checking with Sinar/Bron I found product number 566.38.360, a square sheet of adhesive, for $30.60 per sheet and product 566.38.361, for $3.60 per sheet(two of these needed, one of the first). Clean off the old adhesive with rubber cement thinner and then put the above on the film area & you are ready to go. Not an inexpensive solution. The tech guys at Sinar/Bron did mention one could 'possibly' find a lower cost alternative at hobby shops, though they didn't know about how tacky it would be or how easily film would come off once tapped into place. (especially after being on contact for awhile)

-- Dan Smith (shooter@brigham.net), December 27, 2000.