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Scott
Tinkerer
Username: Scott
Post Number: 67
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 23, 2010 - 11:21 am: | 
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I'm a bit stumped. I have a Ricohflex, one of the gear-coupled-lens TLRs. When I got it, the focus threads were completely seized, so I took it completely apart to clean and put new grease in the focus threads.
Now, I am having trouble getting the taking and viewing lenses to focus at the same distance. I think I got the shutter and both lenses in the same way they came out, with the two flat circular shims in the original place.
I prefer to aim at a focus target that is relatively close, rather than aiming at infinity. I focued the taking lens at 5 feet, then tried to do the same with the viewing lens, but the front element casing comes out of the threads before I can reach the proper focus.
There is a collar that allows for a few mm of adjustment of the distance between the body and the taking lens front element. I tried giving it more or less distance, but still the same problem.
Any tips??
--scott |
Ethostech
Tinkerer
Username: Ethostech
Post Number: 147
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 24, 2010 - 07:57 pm: |
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As you will have discovered, the viewing lens is left-hand threaded so that both lenses have the same axial movement when meshed together. Forget the 5 ft focussing. That's the wrong way to go.
Intstall only the taking lens. Place a ground-glass screen in the film-plane (non-ground surface facing outwards). With shutter on "B" and iris at full aperture, keep the shutter open whilst viewing an INFINITY image through the film-plane and focus the taking lens until all is needle sharp. Mark and index the taking lens position with a felt marker pen. You have finshed with the ground glass screen now.
Unscrew the taking lens until it "Just" exits its thread.
Mesh the viewing lens and then allow both lenses to start in their threads. If when the taking lens reaches its indexed infinity marked index the viewfinder image does not reveal a correponding infinity focus, unscrew both back to the start and shift the meshing a notch or two - then try again.
After a few such adjustments you will find the infinity sync'.
Hope this helps. |
Denny
Tinkerer
Username: Denny
Post Number: 14
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 24, 2010 - 10:47 pm: |
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Which Ricohflex model is it? On mine, there are 3 little set screws, that when loosened, will let the geared collar be removed from the lens. I put the one on the focus lens and left the one off of the taking lens. On a bright moon, I focused the focusing lens on the moon, then the taking lens was focused on a piece of cellophane tape (using a magnifying glass. I have also used waxed paper, but the ground-glass would be the best as Ethostech desribed.
I then put the gear on the taking lens (making sure the taking lens didn't rotate) and tightened the set screws. I then checked it at 7' using a lamp with a textured shade.
Did you remove only the front element? If you removed the focusing screen you did get it back with the glossy side up?
I did have to realign the distance scale collar at the focusing lens as the infinity mark was off. The collar was a little loose, so after realigning, I tightened it a bit. This is the collar that is mounted to the camera.
Good luck. |
Scott
Tinkerer
Username: Scott
Post Number: 69
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 12:25 am: |
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Thanks, guys! I appreciate the input.
I think if I wanted to take photos of the moon, or landscapes, skylines, etc. then I would definitely want to make sure that the images at the ground glass and film plane were identical at infinity.
I think I would rather make sure that the taking and viewing lenses are focusing equally at relatively close distances. In my own experience, at least, there is always going to be a considerable focus error; if I set a lens at infinity, then I see a focus error at close distances. If I set a lens at a relatively close distance, then the error will be at 'infinity'. I want to use this camera for protraits, so I would rather the error be at the 'infinity' end of the scale, rather than at the 'close' end.
It might be picky, but I want to be sure that what I am seeing on the ground glass is the same image that is at the film plane-- at the distances at which I expect to be using the camera most...even if I have to 'hack' it somehow. |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 92
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 12:59 am: |
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You should adjust the focus at infinity, even if you never take a single picture at that distance.
The problem you have isn't "focus errors"; it's the viewing and taking lenses being out of sync. The method given above will get you in sync, so that when you focus on your portrait subject in the viewer, the taking lens will also be in focus. |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 166
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 01:12 am: |
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Not sure if it helps:
http://www.flickr.com/photos/spacelion/2585176584/
http://www.flickr.com/photos/spacelion/2585179208/
The idea is to focus the lenses independently and then join them again - exactly as Denny had said it. The procedure should be the same if you align them at infinity or at 5ft. |
Scott
Tinkerer
Username: Scott
Post Number: 70
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 01:39 am: |
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Of course, I have the geared parts off of the lenses. I was planning to make sure the two lenses were focused to the same distance, and then put the gears on.
I can see plainly that I am not able to get the viewing and taking lenses to focus at the same distance. With a TLR, the whole idea is that you want the taking and the viewing lenses to be focusing at the same distance, right? If you want to make portraits, then you would naturally care more about the taking and viewing lenses being equally-focused at close distances than at 'infinity'.
Hey Rick O., you've helped me many times before. Have you got any good advice for me besides setting my lenses at 'infinity'? |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 168
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 03:43 am: |
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So the problem is that the taking lens can't focus down to 5ft when uncoupled from the viewing lens? Or am I still missing something? |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 76
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 06:14 am: |
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"In my own experience, at least, there is always going to be a considerable focus error; if I set a lens at infinity, then I see a focus error at close distances."
That's not the way it works. If you experience this, then there is another fault somewhere. |
Scott
Tinkerer
Username: Scott
Post Number: 71
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 07:55 am: |
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Yes, the viewing and taking lenses are completely uncoupled when the alumiminum gearded rings are off.
I have the taking lens focused at 5 feet at the film plane. My problem is that I cannot get the viewing lens to also focus at 5 feet because the front element simply comes out of the threads about 15 degrees before I am able to get a sharp focus at 5 feet. |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 77
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 08:10 am: |
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Have you had the lens elements apart? This can happen if you have one of the elements reversed. |
Scott
Tinkerer
Username: Scott
Post Number: 72
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 08:50 am: |
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No, I didn't have the middle elements out of their casings. I have done that a time or two, however! |
Msiegel
Tinkerer
Username: Msiegel
Post Number: 169
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 09:19 am: |
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Okay, I got it now - looks like I'm slow. Is there a chance that the problem might be behind the viewing lens - in the mirror/focusing screen part of the camera? |
David_nebenzahl
Tinkerer
Username: David_nebenzahl
Post Number: 93
Registered: 12-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 11:52 am: |
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Scott: I agree that Rick Oleson would be an excellent person to give advice on this problem.
I still say that adjusting the focus at infinity is the way to go. The real problem to be solved here is synchronizing the two lenses.
Think about it: if you do get both the taking and viewing lenses focused at infinity, they must be in focus at closer distances, because both the lens focal lengths and the distance moved by the focus helix are either identical, or proportional (set by the camera's designer). So there's no need to establish focus at a close distance.
I'm sure someone here with more knowledge than I have can explain this better and more authoritatively. |
Denny
Tinkerer
Username: Denny
Post Number: 15
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 02:02 pm: |
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I'll try again. On the focusing lens, is the focus distance mark top dead center of the camera? Mine had rotated a little bit. If it rotates too far, it may be why the viewing lens is "escaping" at 5'. I didn't disassemble mine far enough to know if the distance scale collar screws in, or is shimmed or if just a loose fit. There was a nut collar on the mirror side that I tightened.
I will check, but I don't think I took many photos of that when mine was disassembled. |
Scott
Tinkerer
Username: Scott
Post Number: 73
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 02:29 pm: |
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On mine, the reference mark for the focus scale (which is on the chrome collar attached to the front plate) is at TDC, and seems quite fixed there.
But when I am focusing the taking lens, I am looking only at the image on the ground glass. The actual focus scale is engraved on the geared aluminum collar which I have not yet put back on the camera. |
Denny
Tinkerer
Username: Denny
Post Number: 16
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 25, 2010 - 06:52 pm: |
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Right - I remember now. It is that gear that has an infinity stop that contacts the d.o.f. scale and mark. Mine focuses down to about 3', so something is definitely out of whack. If the mirror and focusing screen are seated all the way, I have no clue. Please let us know if you find the gremlin.
Good Luck. |
Denny
Tinkerer
Username: Denny
Post Number: 18
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 05, 2010 - 06:40 pm: |
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Scott - I see in another thread where you haven't yet killed the little gremlin. I took my viewfinder off to look again. I can only think of three things. The focusing screen is down (not tight against the upper support), the mirror was replaced with a thicker one, or one of the elements in the viewing lens got reversed. I know someone had worked on mine before I got it. And some of their shortcuts left something to be desired.
I understand you have two of these critters. Is the close focusing problem on both or isolated to only one?
Good luck. |
Scott
Tinkerer
Username: Scott
Post Number: 80
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 06, 2010 - 08:30 am: |
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Yes, I have two, but I only have one good viewing lens. On one of the viewing lenses, I was unable to separate the front element casing from the middle element casing.
Mirror and ground glass are where they should be.
I even switched the taking and viewing lenses (leaving both rear elements in place). Then I got a nice focus on the ground glass as close as 3 feet, but could not focus at the film plane any closer than about 6 feet.
So, you can get a clearly focused image on your focusing screen at 3 feet?? |
Denny
Tinkerer
Username: Denny
Post Number: 19
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 06, 2010 - 09:24 am: |
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Yes - I just set up a yard stick with the camera at one end and a subject at the other. Using the magnifier, the subject snapped into focus. It appears you have narrowed all of the variables down to the moving elements of the viewing lens. Is it possible a previous owner switched viewing lenses from one camera to another? BTW - Mine is a Model VII.
If you can't separate the elements, it would make one think they weren't ever reversed. I am totally out of ideas. |
Leonistik
Tinkerer
Username: Leonistik
Post Number: 14
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 08, 2010 - 02:19 pm: |
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This seems more than I can handle, I haven't even taken out the lens yet, It is stuck and unable to turn and those 3 screws on the top underneath the lens is just not easy to remove I do not know what to use. I am irritated and determined at the same time and then I read about the lens. IT makes me frightened to want to go near this camera |
Scott
Tinkerer
Username: Scott
Post Number: 88
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 08, 2010 - 09:08 pm: |
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I think I just had bad luck and got a camera that never was able to focus properly. One of these days I get another to use for parts, and then I'll have another go at it.
The design is actually quite simple, and not hard to take apart and get back together. |
Titrisol
Tinkerer
Username: Titrisol
Post Number: 5
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 26, 2010 - 04:18 am: |
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All you need to do is to tkae the geared wheels of the lenses and adjust infinity focus for both the focus and the picture lenses.
Use the method in here:
https://kyp.hauslendale.com/classics/collimator.html
Once both are in focus put the gears together so that they will be in sync. |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 15
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 26, 2010 - 04:32 am: |
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Tritisol: Read before you post.
Scott: check the focal length of your viewing lens:
- if you can, remove the viewing lens completely from the camera,
- take another camera that can focus to infinity (no need to be precise infinity for now)
- put the good camera a foot or two from a white wall, shine a torchlight into its viewfinder / onto its ground glass.
- put your viewing lens between the good camera lens (set to infinity) and move it till you get it to project a sharp image of good camera's focusing screen on the wall. Measure distance wall-lens. If it's noticeably different from the stated focal length, you just nailed it.
Note, that you can't determine exact focal length this way, but if a lens is missing an element, or is mis-assembled, often the resulting focal length will be way off.
Marek |
