What happened to vacuum backs?

[bglick]

What happened to Vacuum backs? Schneider used to make a Hi-End back, but now discontinued. Hoffman used to make vacuum backs, can't find them. Any in production today? Any experience using them? I was considering them for 4x5 repro work? TYIA

[Eduardo Aigner]

Thought not a vacuum, Sinar makes the "Sinar Precision Sheet Film Holder".

"For the most exacting demands and for photographs with meticulously defined planes of sharpness, Sinar designed its own metal film holder with a full-size pressure plate and a patented film tensioning system that ensures the best possible film flatness.

Tolerance of the film plane is just 0.03 mm no matter what emulsion you use.

Eliminates any movements of the film during the exposure.

Particularly valuable for photographs with multiple exposures or selective sharpness.

Designed for single sheets of film, which greatly simplifies film loading."

http://www.sinar.ch

[robc]

Linhof still make one.

http://www.linhof.de/english/index.html

look at the aero 4x5 EL and then take a look at the sports section where the back is being used on a master technika.

[bglick]

Eduardo, that is interesting... leave it to Sinar... problem is, I will need a lot them....

Hermit, it seems this is very possible to build.... but a pain indeed...

Rob, interesting, but the Linhof he is using it on is a roll film back? Thats odd? Does anyone know of vacuum back for roll film?

[Richard Ide]

Hi Bill

If you could let me know the following either on the forum or privately email me, I may be able to come up with some viable answers for your situation.

Quantity,
Operating environment - ie all in one location and size of location, indoors/outdoors,
Frequency of use,
Life required,
Film changing facilities,
Do you need a dark slide,
etc.

Richard

[Bill_1856]

Q: "What happened to vacuum backs?"
A: They All Sucked. (Sorry. I couldn't resist.)

[Bob Salomon]

" Thats odd? Does anyone know of vacuum back for roll film?"

No it isn't. Linhof MADE a vacuum roll back for 126mm film on modified NATO spools for the 45 Aero Technika. These backs, in recent years, have been sold to organizations like the Chicago Albuman Works, the National Archives and others for use on the Master Technika on a copy stand for making dupe negs and copy negs.

Most of these companies and organizations have swithed over to digital for these uses and have offered their backss for sale.

These backs are both vacuum and motorized and require 24V aircraft power to operate. Linhof no longer sells the back or the battery packs and chargers. If you can find a Linhof Aerial Roll Back it must be modified to use it on a Technika. And it only fits a 45 Technika.

[ramin]

Bill:

Remember that depth of focus increases at close ups so you don’t really need a precision back for this purpose. Take a look at this post see what Julio Fernandez has written at the end: http://largeformatphotography.info/lfforum/topic/494329.html

Cheers

[bglick]

Bob, can these vacuum roll film backs be modified for 70mm?

Ramin, good point about close focus, it sure helps the Depth of Focus issue... Nice link to Julios post.... flat film holders is surely a good starting point, I use all Toyo Holders, but a flat plan in the film holder is no assurance the film will be flat, as it can take on a life of its own in the hold. Of course all this is measured in .001" increments, which we can not appreciate with vision. But with 8x10 I have tested several sheets of film, and they clearly do not stay flat to the film back.

An interesting solution, but not very practical, for 810 film flatness would be a "right angle" camera design, so gravity can work in favor of film flatness, instead of against it. A reflex viewer, with right angle would ease the ground glass composition. Only for use with normal to long lenses.

[Bob Salomon]

Bill,

No. The Linhof Aero Technika accepted two long roll backs, one was the vacuum 45 back that used 126mm film. The other was the 70mm back that used sprockets to maintain film flatness. The 70mm back kept the film as flat in the 70mm back as the 45 vacuum back did in its back. The 70mm version can also be mounted to a Technika, requires the same 24v power supply and requires the same modification to use it on a Technika.