Shimming hood to match focus

[astrosecret]

Howdy. I recently picked up another Rollei. this time a Rolleicord V. Shutter and optics are great but pictures were slightly soft, seemed focus was being pulled in front of the subject. I pulled focus in 4k for a living so I'm hoping my eyes are telling me the truth.

When I used a tape measure to measure the distance from the film plane to the subject, the readout on the focus knob was indeed reading short, but the image appeared in focus through the hood.

It seemed the camera had an aftermarket screen which was not properly shimmed (felt plasticky, has a brighter bulbous center to find microfocus).

So I shimmed the hood. Took a couple hours to get it right, but now the image in the hood is in focus while the subject is at the proper distance according to the focus knob and my tape measurements.

I guess my question is, am I done? Anything I missed? I realize the best thing to do is take it to a pro who will charge me a couple hundred to open the focus knob and realign everything. Since that would cost more than the camera, I'm hoping this will get me 90% of the way there.

 

[charjohncarter]

My Rollei focus knob is off but my screen is original and I get right on images. It seems to me that you still have to run a roll through camera using your shimmed screen to see if it is 'on.' Or you can get a frosted glass and open your Rollei up so you can check focus by the lens (frosted glass) and then check your shimmed screen.

 

[astrosecret]

I guess I would need some ground glass to know for sure. another week waiting on eBay I guess :bang: unless anyone nearby in la can help out 🙄 pretty confident the old girl was focusing a bit forward, as every shot seemed to be focused inches ahead of the subject in my test roll. As I understand it the focus marks should be 100% accurate to the film plane.

(I would really like to know if this screen is original or find the original screen for the Rolleicord V.)

I found some good info here https://www.flickr.com/groups/87036574@N00/discuss/72157628944725557/
I guess I will be trying to procure some 6x6 ground glass

 

[charjohncarter]

I used a piece of plastic and used 220 sand paper to frost. Not the perfect solution, but it worked. I have used some frosted tape scotch tape across the opening but be sure it is at the film plane.

 

[retinax]

Making actual ground glass also isn't hard. You need a shard of glass, pliers to break it to size and sand paper to frost it (make it wet and do it in the sink, you don't want glass particles flying around). I wouldn't rely on the scale on the focus knob to be very accurate, they're often a bit off. But as you've already done it, might as well shoot a test roll if you're frustration tolerant.

 

[Hari]

Another path is to get a Rolleisheet film back kit as
it has a ground glass, but might take longer
to find.

 

[astrosecret]

Thanks for the ideas. Making my own would work. Is standard operating procedure to pull to infinity on the knob and check marks on upper and lower lenses? Id imagine 3-6ft would be more important and infinity on my lens in over 60ft; i expect it may be difficult to see details 90 ft away focused on a small frosted shard of glass?

 

[retinax]

You'll need a loupe. I don't know what's proper procedure but I'd first check if infinity on the taking lens matches the scale/hard stop and then see if both lenses are in sync at a close distance, easier to see as you say. 90 ft away is not far enough for infinity.

 

[retinax]

By the way, on most TLRs the proper way to match focus on both lenses is adjusting their distance from film plane/screen by screwing them in or out of the lens board, don't know of the Rolleicord is different in that regard. At least if infinity on the taking lens is off you have to do that, to correct a mismatch, shimming the screen might work fine though.

 

[BernardL]

I guess I would need some ground glass to know for sure.

You don't need a ground glass. See:

http://rick_oleson.tripod.com/index-123.html
http://feuerbacher.net/photo/repair/InfinityFocus/InfinityFocus.html


Good luck

 

[charjohncarter]

Thanks for the ideas. Making my own would work. Is standard operating procedure to pull to infinity on the knob and check marks on upper and lower lenses? Id imagine 3-6ft would be more important and infinity on my lens in over 60ft; i expect it may be difficult to see details 90 ft away focused on a small frosted shard of glass?

Forget the knob, be sure your ground glass, scotch tape or whatever you use to focus on also has perfect focus with the viewing screen. You don't need to start at infinity do as you say 3-6 feet.