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

[violin]

I am just doing some Polarid tests on a Linhof Master Tecnica, and it seems stra nge 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 4m m off top to bottom (horizontal image) and rotated about 3 degrees clockwise. Th is 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 tim e and I'm missing some kind of technical now how, right?, or that the camera nee ds a mechanic or something? I mean my 35mm rangefinders are spot on, and the SLR s too, I really like to use full frame and be confident about it...

Thanks everyone

[David Brown]

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

[violin]

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....

[QT Luong]

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.

[violin]

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...

[Jorge Gasteazoro]

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.

[M.]

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

[Natha Congdon]

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

[violin]

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

[violin]

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.