Rolleicord parallax correction adjustment question

What About Bob

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My Rolleicord does not have the compensation frame for parallax correction in the finder. Is there an attachment for the Rolleicord that would adjust for parallax?

The finder has little screws on the sides. It doesn't just come off.
 

Kino

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What's your minimum focus distance?

Remember, anything closer than the printed minimum focus distance on the dial requires close-up attachments, which have parallax compensation built in.

You could just put some frosted film (sandpaper and some scrap 120) in the gate, open it on "B", place the camera at minimum focus distance and frame-up your target. Compare it to the viewfinder and put markers on in the VF to denote the upper frame line.

At least you would have the framing for minimum focus distance and could infer from that line your parallax to more distant subjects...
 
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What About Bob

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Kino said:
What's your minimum focus distance?
Click to expand...

Minimum distance is 3 feet/0.9 meters.


That sounds great! Thanks Kino
 
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What About Bob

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I wasn't able to use the camera on my tripod for this so I tried resting it on my bureau. Not exactly a convenient method. I framed up my shot in the finder then put some scrap film in the gate and I got lost at that point. Am I supposed to see a projected version of the image from the taking lens? Maybe I need something more reflective or am I doing this wrong? This test would have been ideal on a tripod but I cannot open up the back while the camera is mounted.
 

Kino

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You should be able to remove the back (a clip on the back left side where the back hinges) and set it on a rigged platform. The base is flat, but be careful you don't knock it off the platform! Lash it down with painter's tape or something that wont' hurt the finish (gotta be creative!).

Set the shutter on "B" with a locked cable release and point it at a bright subject. You may have to make a temporary dark cloth to see the image, which will be upside down and backwards!

It will take some fooling around, but with patience you should be able to do it.
 

reddesert

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If you have the camera on a tripod already, just raise/lower the tripod head by the distance between the viewing and taking lenses, which is likely about 2" or 50mm. That will show how your view changes due to parallax. A Mamiya Paramender is an accessory for doing the same thing repeatably.

I think one of the things Kino is getting at is that, if your subject is a couple of meters or more away, the effect of parallax is pretty small.
 

MattKing

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If your viewing lens is, e.g. 2 inches higher than your taking lens, the frame you see is two inches higher than the frame the film sees.
So find something like a book that is as thick as that distance, and between viewing and taking the picture, put the book under the camera to raise it up the necessary amount.
Once your camera to subject distance is more than 10 times the focal length of the lens, the effects of parallax become relatively inconsequential for almost every subject.
 

MattKing

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The Mamiya paramenders are designed to deal with the specific distance between the centre of the optical paths of the taking and viewing lenses found on Mamiya TLRs. If you are thinking of using one with a Rolleicord, you should check whether the Rolleicord has the same (or very nearly same) distance between the optical centres of its lenses.
 
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What About Bob

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Out of curiosity I measured the lens distance and got 1 and 11/16ths inches. I will frame and then shift the camera up by 1 and 11/16 and check out what the difference looks like.

The lens is a 75mm - so 75 * 10 = 750mm/25.4 = 29.5 inches or 2 feet and 5.5 inches. That is 6.5 inches away from the minimum focusing end
 
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What About Bob

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If the default lens distances for those cameras are about 2 inches then mine would be about 5/16ths lesser.
 

BrianShaw

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Hi Bob. The parallax difference is less than 1/4 inch. I’m visualizing the mask in my Vb and would measure it for you if it weren’t packed away. It’s very easy and effective to compose a bit generously and crop rather than compose to the very edge of the frame.
 

guangong

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By now you should realize that nobody wants a simple solution!
 

Dan Daniel

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Here's a 'Cord parallax mechanism. The bars are about 4mm, a bit over 1/8" wide. In use they move about this distance, a bit less.

All in all I'd suggest that if you need tight framing on the final negative at close distances, use an SLR?
 

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BrianShaw

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… and make sure it’s a SLR with a 100% viewfinder!
 

ic-racer

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The paramender can be raised less than full height (for cameras with lenses closer than the Mamiya. )
Also, the distance that the two images (top and bottom) will be discordant is always the exact same as the distance between the lenses irrespective of the subject distance.
 

JPD

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I wonder why anyone would have wanted to remove the parallax compensation mechanism from a Rolleicord? I have never seen one without it.
 

Dan Daniel

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Minolta made a device called a Paradjuster to do something similar to the Mamiya device but set for the right lens distance for the Autocord, which is the same lens distance as the Rolleicord.

 

BrianShaw

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Correct me if I'm mistaken, Dan... but isn't that for when using close-up lenses rather than the normal focus range. I always that it was the Minolta equivelant of a Rolleiparkel, although Milolta also made prismatic correction lenses if I'm not mistaken.
 

Dan Daniel

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Brian, this would work at any focus distance. It, and the Mamiya mount, is the real parallax correction method, not the ersatz moving frame in the viewfinder or prism and such which still suffers from parallax no matter what you do. So you focus, with or without a diopter as needed on the viewing lens. Then you move the camera so that the taking lens is in the same point in space, move the diopter if being used, and take the photo.

Parallax is the offset that comes from looking at the same object from two different points in space. Anything short of moving the viewpoint to the same point in space will still have parallax. Frames, prisms, etc. are crude ways to give a rough idea of framing changes, not much more.
 

BrianShaw

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Yes, we have same understanding of parallex and agree. Without a doubt, the Minolta Parajuster could be used if the need for that kind of framing accuracy is great enough.

My point is based more in practice than the physics... that in the normal focus range of a Rollei (or a Minolta Autocord), the amount of parallex correction needed is quite small at the closest focus without an accessory close-up lens. You demostrated that in post #14. Also reference the Minolta Autocord user manual.

There is no getting away from parallax in a TLR, and no need to treat parallax or engineering solutions to parallax effects like the devil either.
 

Dan Daniel

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Yeah, I try not to get on my high horse about how wrong the word 'correction' is in 'parallax correction.' Along with TLRs, it is used for rangefinder cameras like Leicas and Fuji GS690s, etc. About as useful as arguing over the use of it's, not its, for the possesive. And don't get me started on using 'impact' for 'affect.'

I'm not a good one to talk to about this, anyway. I am very lax and relaxed in my use of viewfinders that are not SLRs or digital. Other than focus, they are crude guesstimates and I frame roughly and based as much on experience of a camera and lens as on what is actually shown in the viewfinder.
 

BrianShaw

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No problem, Dan; that as a good tutorial...
 
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