W.Y.S.I.W.Y.G. Focusing Screen to Film?

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I am just doing some Polarid tests on a Linhof Master Tecnica, and it seems strange to me that what I see on the focussing screen (a Beattie Interscreen) is not what I get on the Polaroid print.

So my idea is that I am using a 9 x 12 cm camera, and I would like to be able to frame a 9 x 12 cm image, but not so, it is about 7mm off left to right about 4mm off top to bottom (horizontal image) and rotated about 3 degrees clockwise. This means that my useable image area is about 7 x 9 cm (kind of medium format).

OK someone experienced in these matters please tell me that this is my first time and I'm missing some kind of technical now how, right?, or that the camera needs a mechanic or something? I mean my 35mm rangefinders are spot on, and the SLRs too, I really like to use full frame and be confident about it...

Thanks everyone

-- adrian tyler (tyler@nova.es), October 20, 2001


Which Polaroid film are you using? Pack film won't give you a full 4x5 image.

-- Dave Brown (wolfgang@peakpeak.com), October 20, 2001.

Sorry, I should have explained more. The filmback is a Polaroid 545i.

I was assuming that the screen image as seen on the "Beattie" which measures 9.5 x 12 cm, would ( more or less ) correspond to the image on the film area on the 545i which also measures 9.5 x 12 cm.

When I saw the results, I took the lens - symar 150 - off of the camera anfd looked in, with and without the filmback on, horizontaly, loading from the left hand side. I see that 545i has about 2.5 mm "bleed" top and bottom and 1 mm on the right hand (looking from the GG side).

The print makes an image of 9 x 11.6 cm, si I work that out at 4mm image cutoff, but what I can't work out is that, the image on the print is so off centre and rotated!

The camera is squared off to a 1 x 2 m rectangular pictureframe, about 3 m away.

Thanks I hope that makes sense....

-- adrian tyler (tyler@nova.es), October 20, 2001.

You're not missing anything. Polaroid film's surface area is significantly smaller than 9x12. Note also that when you're using "real" film in cut film holders, the rails which hold the film eat also a bit of surface on the edges (nowhere as much as Polaroid). I don't remember if this is the case with the Quickloads or readyloads, but anyway the name of the emulsion is printed near the edge too. So it's not really feasible to use LF "full-frame". You might want to put masks on your ground glass if this concerns you.

-- Q.-Tuan Luong (qtl@ai.sri.com), October 20, 2001.

I must be stupid or something, I just don't understand, because if I mask according to the results I see on the screen, then I would need a 7 x 9 cm mask (rotated 3 degrees, 7 mm to the right 4 mm up on a horizontal image) on a 9 x 12 cm to make sure I can see what I am going to get. That is to say with this camera and lens combination.

What I don't get is that, the lens is projesting a 9.5 x 12 cm image on the GG, but this particular film picks up a 9 x 11.5 cm image, which really has nothing much to do with what I have just framed, I mean by anyone's tollerances it is way off.

This can't be "normal" procedure, 1. you waste tons of emulsion 2. you gotta really guess framing your pics...

now I'm going to start apologising for not getting it...

-- adrian tyler (tyler@nova.es), October 20, 2001.

Adrian what they are trying to tell you is that the area of film exposed in a polaroid back is smaller than a regular film holder because of the construction of the polaroid back. In other words your image has not shrunk, you only have exposed part of the image because the available are in the holder is smaller. Yes, when you are framing you are not really guessing but you must frame according to the film you plan to use, if you are going to use polaroif p/n 55 and want the negative then you should frame so that the image is contained in the smaller area. If OTOH you are going to use a "regular" film the you should frame using the entire area and use the polaroid to check exposure.

-- Jorge Gasteazoro (jorgegm@worldnet.att.net), October 20, 2001.

This is all clearly explained in the directions/information sheet that comes with the Polaroid film. When all else fails, read the directions!

-- Wilhelm (bmitch@home.com), October 20, 2001.

The respondants seem to be missing his main point: somehow he is getting a Polaroid image which is not centered as his GG image is. That is not standard for Polaroid or any other kind of back in my experience. Is the 545i properly centered on your Linhof? This kind of displacement and particularly clockwise rotation that you report is not to be expected in my experience. Either the film is not seating properly in the holder, or the holder not seated properly in the back. Anyone w/ more experience in Polaroid care to comment?


-- Nathan Congdon (ncongdon@jhmi.edu), October 21, 2001.

Thanks to everyone for the explications, I think before I ask any more I will shoot some "real" film under the same circumstances.

Nathen's comment, however, is really the essence of what I feel, in that I understand that with the Polarid I will experience some image cutoff, my problem is that is is so off centre and rotated.

Being off centre may be explained by the film size, the rotation I thing may be due to the screen being a little rotated... I don't know I l'll report back on the results using normal film in another back.

Thanks for your patience. adrian

-- adrian tyler (tyler@nova.es), October 21, 2001.

Nathan, as far as I canss the fimback is properly fitted, looking in throth the fron with no lens on and the back fitted it all loos fine, I have even looked with film inserted and open and don't see that it and be fitted, or exposed any other way.

-- adrian tyler (tyler@nova.es), October 21, 2001.

ah, ok cut of and rotated.....you should have explained that more clearly. Do you have a reversible or rotating back? I beleive the master technika has a rotating back, and I think you have your back rotated just a little..which would be the cause of your film showing this type of image. Check back that your film back is either totally vertical or horizontal and that it does not move when you insert the film holder. Good luck.

-- Jorge Gasteazoro (jorgegm@worldnet.att.net), October 21, 2001.

When I first started using my 545i holder, I had a similar problem. It turned out that I wasn't putting the holder all the way into my camera. There's a little ridge that prevents the holder from sliding out (normal film holders have it too) and I was stopping when it hit the top of the camera instead of pushing the holder the 5 mm extra until it was fully in the camera.

If that's not the problem, remember that the polaroid instructions state that the recorded image is not centered on the ground glass and is quite a bit smaller than the full 9x12 area. They suggest that you mark your ground glass if you want exact framing.

-- Nathaniel Paust (paustne@whitties.org), October 21, 2001.

I've made some tests on "real" film and will take them to the lab tommorow, the 545i is inserted correctly, that is to say if i put it n amymore it comes out through the bottom of the camera and is no longer flat aginst the camera.

Judging by all the responses the "real" film should be ok, not so decentred and my problem seems to be is conceptualising GG to film. With my rangefinders, with experience, I know how to compensate. I felt that the GG would be more like SLR, that is to say EXACTLY spot-on.

Seems like I need to do more work...

thanks, Ill post on the film test


-- adrian tyler (tyler@nova.es), October 21, 2001.

To try and makethe ppoint many other people have tried to say here:

The image on a Polaroid 4x5 image, example: Type 55 or Type 59 film, used in a Polaroid type 545 or 545i holder (probably the older type 500 holder as well. is not truely symmettrical, since you lose about 7mm on one edge ofthe imaging area the center of the image just seems shifted over that much. There is no problem with your camera, your back of your film stock.

-- Ellis Vener Photography (ellis@ellisvener.com), October 21, 2001.

I got the test back from puting a sheet of Readyload in the 545i and as mentioned by all above it was SPOT ON, no cut off, no rotation, as seen on the GG.

Now to see how to fix the light leak on the 545i+Readyload, Ho-Hum...

Thanks to all

-- adrian tyler (tyler@nova.es), October 23, 2001.

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