VIOOH / Imarect possibly out of alignment?

[MrRom92]

I mine is not subtle, it is very easy to see it move: from 3.5 feet to infinity.

Maybe that is an indicator that something really is wrong with it afterall… oy

Only slightly unrelated question but I’m curious, with a fixed accessory VF like a SBOOI or something, how do you compensate for parallax? Am I not mistaken that the dedicated 135mm VFs are also fixed and don’t have any sort of compensation mechanism? It seems like it’d be a lot more critical there. But somehow, all the old-timers made it work for them…

 

[charjohncarter]

Sorry, I don't know about SBOOI. But mine (VIOOH) is good as long as I use it on my IIIf (and I remember to use the parallax correction lever). So good, even with my 50mm Elmar lens I use it for correct framing. It is easy to 'down rap' (as one of my then hip employees told me many years ago on a none photographic subject) Leica (in the IIIf period), but it was not an organization that made products that were not just thrown out to the public to see if they would sell. They made good stuff back then (and possibly still do).

 

[Dralowid]

From memory Leitz SBOOI (the 50mm bright line viewfinder) has a dotted line that marks where the top of the frame would be at 3ft or 1m

 

[peterm1]

From memory Leitz SBOOI (the 50mm bright line viewfinder) has a dotted line that marks where the top of the frame would be at 3ft or 1m

A lot of simple accessory viewfinders use this system. It is left to the user to become accustomed to using this system and make the necessary decisions and adjustments.

 

[Malcolm M]

Only slightly unrelated question but I’m curious, with a fixed accessory VF like a SBOOI or something, how do you compensate for parallax? Am I not mistaken that the dedicated 135mm VFs are also fixed and don’t have any sort of compensation mechanism? It seems like it’d be a lot more critical there. But somehow, all the old-timers made it work for them…

The finders for longer focal lengths have a rim-set distance scale.

 

[sreed2006]

For accurate framing, what is needed is to have is the center of the picture seen through the finder to be the actual center of the picture the camera takes. The field of view (width and height) are a different matter, but those can also be determined with a similar technique as discussed here.

Put the camera on a tripod in a room with a flat level floor, where you can move the tripod from 3.5 feet away from a wall to about 20 feet away. On the wall, put a dot at the same height as the camera's lens. Put an arrow next to dot showing which direction is up. Set the VIOOH to 135mm, so the frame is smallest (the goal is to be able to place the dot at the center of the frame, and the 135mm setting makes that easier.) At 3.5', 5', 7', and 15', accurately focus the lens, and transfer the distance indicated on the lens to the VIOOH's distance setting. Take good notes, such as
Frame 1 landscape at 3.5',
Frame 2 landscape at 5',
Frame 3 landscape at 7',
Frame 4 landscape at 15',
Frame 5 landscape at 20',
Frame 6 portrait at 3.5',
Frame 7 portrait at 5',
Frame 8 portrait at 7',
Frame 9 portrait at 15',
Frame 10 portrait at 20'
Then, go outside and pick a point at infinity, focus the lens, set the VIOOH to infinity, and take a landscape and portrait shot with the chosen spot at the center of the frame.
Frame 11 landscape at infinity,
Frame 12 portrait at infinity.

Develop the roll of film, and check each frame to see if the expected center is the actual center of the negative (such as by drawing an X across the negative from opposing corners).

If the expected center is not at the negative's actual center, then you know you need to either compensate for the inaccuracy of the VIOOH, or (and I don't know if this is possible) have the VIOOH recalibrated.

I hope this helps. I have a VIDOM which does not match the framing shown in the viewfinder of my IIIg, so will probably do this myself in the near future.

 

[Malcolm M]

Another, possibly simpler, method if you have access to a flat horizon (sea, Norfolk...).
Set up a tripod and level the head (spirit level).
Mount the camera with finder set to infinity.
The horizon should run across the middle of the frame of the finder.

 

[Dralowid]

Should have mentioned this earlier. I had an old VIOOH that was filthy within. I pulled it apart and the prisms came apart also.

If they are not cemented back 100% the image can be offset etc. It took me a few goes to be satisfied with the result.

 

[farlymac]

I like the single focal length finders with the dial adjustment, but having to carry three or four finders is sometimes a hassle. And expensive, especially for the 50mm finder. However, their smaller size is more to my liking as it keeps the total weight down, and is easier to get the camera in and out of the bag with the finder attached.

I had to cement the prism in the first finder I bought (got it really cheap because of the issue), and got the alignment pretty much spot on. But I didn't use an actual optical cement, plus the old cement was not removed, so now it's not the clearest finder around.

I tried to access the framing on the second VIOOH from the rear when doing a cleaning, and found you have to go in from the front. Not having instructions at the time on how to do that I figured I can put up with the crookedness a little while longer until I figure out the proper procedure. Or replace it with some single focal length finders.

PF

 

[peterm1]

I like the single focal length finders with the dial adjustment, but having to carry three or four finders is sometimes a hassle. And expensive, especially for the 50mm finder. However, their smaller size is more to my liking as it keeps the total weight down, and is easier to get the camera in and out of the bag with the finder attached.

I had to cement the prism in the first finder I bought (got it really cheap because of the issue), and got the alignment pretty much spot on. But I didn't use an actual optical cement, plus the old cement was not removed, so now it's not the clearest finder around.

I tried to access the framing on the second VIOOH from the rear when doing a cleaning, and found you have to go in from the front. Not having instructions at the time on how to do that I figured I can put up with the crookedness a little while longer until I figure out the proper procedure. Or replace it with some single focal length finders.

PF

May I ask what you used to cement the prism? I have a lovely old turret finder and several years ago when I took it out of storage to use I found that the eye piece was blank. Most likely the internal prism had separated (though it seemed to be in perfect condition previously - no visual signs of separation). I had thought a few times about how to fix it as the exterior and the optics (other than this problem) are faultless. I once search to find optical balsam and while Canada Balsam is available on eBay I have been told it is not pure enough for optical purposes. I believe there are optical glues though........any info you can provide? Thanks in anticipation.

 

[farlymac]

May I ask what you used to cement the prism? I have a lovely old turret finder and several years ago when I took it out of storage to use I found that the eye piece was blank. Most likely the internal prism had separated (though it seemed to be in perfect condition previously - no visual signs of separation). I had thought a few times about how to fix it as the exterior and the optics (other than this problem) are faultless. I once search to find optical balsam and while Canada Balsam is available on eBay I have been told it is not pure enough for optical purposes. I believe there are optical glues though........any info you can provide? Thanks in anticipation.

There is an optical glue that you need to cure with strong UV light, and since I didn't have such a light I used Weldbond because it dries clear. If I had been able to clean off the old glue I might have gotten a clearer view, but it was more just an experiment as I basically got the finder for cost of postage.

PF