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

[adrian_tyler]

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.

 

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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).

 

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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...

 

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Thanks everyone

[david_brown1]

Which Polaroid film are you using? Pack film won't give you a full

4x5 image.

[adrian_tyler]

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

 

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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.

 

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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).

 

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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!

 

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

3 m away.

 

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Thanks I hope that makes sense....

[qtluong]

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.

[adrian_tyler]

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.

 

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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.

 

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This can't be "normal" procedure, 1. you waste tons of emulsion 2. you

gotta really guess framing your pics...

 

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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.

[wilhelm]

This is all clearly explained in the directions/information sheet

that comes with the Polaroid film. When all else fails, read the

directions!

[nathan_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?

 

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Nathan

[adrian_tyler]

Thanks to everyone for the explications, I think before I ask any more

I will shoot some "real" film under the same circumstances.

 

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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.

 

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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.

 

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Thanks for your patience.

adrian

[adrian_tyler]

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.

[jorge_gasteazoro]

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.

[nathanielpaust]

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.

 

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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.

[adrian_tyler]

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.

 

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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.

 

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Seems like I need to do more work...

 

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thanks, Ill post on the film test

 

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adrian

[ellis_vener_photography]

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

here:<P>

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.

[adrian_tyler]

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.

 

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

 

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Thanks to all