Infinity focus issue on 6x9 Folding Camera (Adox Sport) - why does this happen?

[Ellyrion]

I recently bought an Adox Sport 6x9/6x6 Folding medium format camera. It is a pretty typical design for a post-war folder, with a flip up viewfinder and shutter-release on the body,and has a Prontor-S Shutter behind its Steinheil-Cassar f4.5 lens. It's in wonderful condition and the speeds seem pretty accurate for its age, 1 second seems around 1.5 which isn't bad at all.

I had hoped this would be a simple, effective way to get into 6x9 medium format but it seems I've got unlucky - the camera focuses past infinity with the lens set to the infinity mark and results in blurred landscapes, if you actually want infinity focus the lens needs to be set between the 20-30 ft marks (i've verified this by testing with ground glass). Otherwise the camera works perfectly at close range, test shots at the closest focus distance of 3.3ft were fine - but it seems the further out you focus the more misaligned the focus becomes until you have totally blurry images.

I bought it from Ebay for around £75 from a lovely seller so I've sent him a message and am sure I can return it if I want, I guess my question is, given its condition and accurate speeds, is it worth trying to calibrate the lens myself? There are some other similarly specced cameras out there that I could buy instead (like an Ensign Selfix 820) but I'm just anxious I'll likely have another camera with issues on my hands - I have no idea what causes these lenses to go out of alignment like this after all. I'd love to get a more modern 6x9 camera but I just don't have the budget for that, and this camera seems pretty close to ideal if I can get it to work.

Would love some input on how to go forward, and here are some photos of the focus issue: The ground glass photos show the blurred image you get when on the infinity focus mark versus focusing to infinity by eye at the 20-30ft marks, and then the flower photo shows the focus at 3.3ft versus the landscape at infinity focus.

ADOX Sport II Camera at Historic Camera

Thanks!

Additionally -There is a VERY stiff aperture selector ring that I suspect will need regreasing - any ideas on a good lubricant for this?

 

[ic-racer]

Any old camera is going to be riddled with issues. If the infinity spot being off is all that is wrong with that one, I'd keep it. Usually the scale around the lens will need to be freed, rotated to the correct position, and re-affixed to set infinity. Some trial and error to get it right on.

 

[Dan Daniel]

First, I cannot get to your images on Imjur. Not sure what is going on. Maybe ad blockers are stopping me.

Second, as ic-racer says, there is usually a way to loosen the focus scale around the lens. Often three very small set screws in the side. Depending on the setup and what you are willing to risk, you can remove the scale, set infinity, and replace the scale. Or with scale tightened, set to infinity, then loosen scale and set it to infinity.

If it does have set screws, be gentle on them. Find a screwdriver that fits the slot snugly. Very easy to break off one side of the slot.

The aperture setting is hard to say without seeing specifics. I would not add lubrication. You might try drops of lighter fluid on the outer part of the aperture dial. Most likely the shutter is simply old, dirty, with gummy grease and oil that has migrated. So cleaning is the answer, not pouring lubrication on top of dirt. I suggest at most very light application of lighter fluid to see if it has any effect, and then simply use the camera for a bit to shake it out and see if other issues fall into place.

(The 1.5 second speed for 1 second is a solid sign that the shutter needs a cleaning; that is far out of spec. But again, shake out the camera, focus, etc. check for leaks, and see what happens. using a shutter with inaccurate speeds is no biggie other than meaning that the dirt and grease will be putting stress on the internals but you aren't shooting 5 rolls a day so relax for now.)

 

[gone]

Something is off if the shots are soft at infinity and sharp close up. Look for: a lens rebuild where the optics may have been aligned in error, someone had the camera apart and started the lens helical threads in the wrong place, etc. Put the camera on a tripod or something w/ a GG on the film rails and the shutter on B, and see what the lens is up to at different distances w/ a loupe.

The lens will probably have to come off the lens board to fully ck things, so ck to see if a spacer may be missing too.

 

[Ellyrion]

Thank you all for the advice!

I loosened the screws as suggested and used the ground glass from my broken Yashica mat to find infinity focus - which I then managed to drop and smash unfortunately, pretty stupid really. Once I had got infinity focus with the ground glass and a loupe I then used the 'camera as a collimator' method shown in this video:

This method agreed with the focus that I had found with the glass and all seemed sharp. I've tested the lens at around 10ft and it seems to be sharp in agreement with the markings on the lens itself - although I feel like the only way I'm really going to be able to know for sure is putting another roll through it. Infinity focus seems to be sorted at least, and that is really the most important bit for me!

 

[beemermark]

Unless I'm wrong the Adox Sport doesn't have any type of rangefinder or other focusing method. You guess the distance and set it on the lens. If setting the lens at 30' give you everything in focus why worry about where the infinity mark? Never understand why people worry so much about a camera lens infinity marks not aligning with infinity. However it's highly unlikely that there is an issue with the lens. Are the struts firmly locking in place, not bent, bed fully down, etc.

 

[ic-racer]

Infinity is the most critical point to set focus correctly. Off by fractions of a millimeter will cause the whole thing to go blurry.

 

[Ellyrion]

Unless I'm wrong the Adox Sport doesn't have any type of rangefinder or other focusing method. You guess the distance and set it on the lens. If setting the lens at 30' give you everything in focus why worry about where the infinity mark? Never understand why people worry so much about a camera lens infinity marks not aligning with infinity. However it's highly unlikely that there is an issue with the lens. Are the struts firmly locking in place, not bent, bed fully down, etc.

Well the issue for me was that, as the infinity stop was off, all of the other ranges were off too - and I didn't really fancy going through every possible distance marking to see what its true focus was.

The good news is through both the ground glass and collimator method it looks like I have ininfity focus set! These are pretty crap scans from a local lab (just needed them quickly) but its all looking sharp . The last photo I took of some cranes at infinity focus was to check that all of the details (cables etc) were sharp and its looking good! Other distances look good too - the plant was exactly 7ft from the lens and the lens set to 7ft (and shot at f4.5 to check focus) and it looks fine to me! Will shoot this camera at F5.6+ most of the time anyhow, got it for landscapes really!

Sorry Imgur doesn't seem to want to work - this might: https://drive.google.com/drive/folders/1rQ7n7hQEez2s-528iTdWI7T-SjgDV0mS?usp=sharing

 

[beemermark]

Glad you got it figured out (I was no help - ) I thought from your original post that it focused correctly except when set at infinity.

 

[Ellyrion]

Glad you got it figured out (I was no help - ) I thought from your original post that it focused correctly except when set at infinity.

No worries at all! Unfortunately I still haven't figured out the stiff aperture selector dial - its so stiff and requires so much force moving between f8 and f4.5 that I'm afraid I might bend the supporting struts. The guy who sold it said he tested the lens on a Canon camera, so I reckon in putting it back on something has been over-tightened, I'll have to leave it for now as I have a trip this weekend where I'll likely be shooting landscapes so wont need to go below F8 - and I really dont fancy readjusting the focus again as I'll need to do that if I take the camera apart.

 

[Dan Daniel]

If the shutter block was removed and reinstalled, probably a good chance that a spacer is missing or bent or out of position. This will mess up the aperture dial. Some day, probably after your trip, you can try loosening the shutter block from the inside back of the lens board. Get it slightly loose, give it all a jiggle. While loose, see if the aperture dial is moving easier. On most shutters, the aperture lever is part of a large disk on the very back of the shutter- you might see the edge of this disk at the back of the shutter when installed. Serious binding is often from external pressure on this back disk, not from internal issues.

I'd use the camera for a bit. When you are up for it, you can remove the shutter block, reset the spacers and unjam the aperture dial. But then you are in for resetting infinity on the lens, and you've done enough of that for now! Once you spend some time with 6x9 negatives you'll possibly do this on a winter evening.

 

[Ellyrion]

If the shutter block was removed and reinstalled, probably a good chance that a spacer is missing or bent or out of position. This will mess up the aperture dial. Some day, probably after your trip, you can try loosening the shutter block from the inside back of the lens board. Get it slightly loose, give it all a jiggle. While loose, see if the aperture dial is moving easier. On most shutters, the aperture lever is part of a large disk on the very back of the shutter- you might see the edge of this disk at the back of the shutter when installed. Serious binding is often from external pressure on this back disk, not from internal issues.

I'd use the camera for a bit. When you are up for it, you can remove the shutter block, reset the spacers and unjam the aperture dial. But then you are in for resetting infinity on the lens, and you've done enough of that for now! Once you spend some time with 6x9 negatives you'll possibly do this on a winter evening.

Thank you for your reply! Yeah I think its the most likely explanation - hoping that nothing is bent out of place and it's just a pressure issue but yeah I'm going to leave it for a bit before I open it up!.

I was just wondering if you have any thoughts on ground glass for checking focus - I can get another piece of ground glass that would fit the camera for around £18 but I have just seen my local camera shop has a marked Split image Rolleiflex focusing screen for just £10 which seems like it could be even better for checking focus is accurate - I'm guessing I would be good to use this provided it fits the film rails alright?

The only issue with these screens it seems is that you cant always use a loupe to check focus with them as they're too thick (or at least I had that issue when trying to check focus with my Yashica Mat fresnel focus screen before I broke it ), but I guess I can always use a macro lens and a digital camera to zoom in on it instead - the split image seems like a very useful thing to have!

 

[John Koehrer]

Howz about glass from a thrift store picture frame & grind it yourself,
It's not difficult at all. Maybe with 1000 grit or finer wet or dry sandpaper

 

[Dan Daniel]

I was just wondering if you have any thoughts on ground glass for checking focus - I can get another piece of ground glass that would fit the camera for around £18 but I have just seen my local camera shop has a marked Split image Rolleiflex focusing screen for just £10 which seems like it could be even better for checking focus is accurate - I'm guessing I would be good to use this provided it fits the film rails alright?

The only issue with these screens it seems is that you cant always use a loupe to check focus with them as they're too thick (or at least I had that issue when trying to check focus with my Yashica Mat fresnel focus screen before I broke it ), but I guess I can always use a macro lens and a digital camera to zoom in on it instead - the split image seems like a very useful thing to have!

The YashicaMat screen is two pieces. A Fresnel plastic lower piece and a ground glass upper piece. The actual image you use to focus is on the gorund glass surface. If you had the plastic in there, you would be very off as the thickness of the plastic sets the image plane off of the proper surface.

The Rollei screen will have the focus plane and the bottom side of the screen on the same surface. But you will need to trim it down most likely- later Rollei screens are larger than the width of a 6x6 or 6x9 image.

I've tried differnt focus aids for setting infinity. I seem to keep coming back to plain ground glass. John Koehrer's suggestion to make your own is as good as any source.

 

[Ellyrion]

The YashicaMat screen is two pieces. A Fresnel plastic lower piece and a ground glass upper piece. The actual image you use to focus is on the gorund glass surface. If you had the plastic in there, you would be very off as the thickness of the plastic sets the image plane off of the proper surface.

The Rollei screen will have the focus plane and the bottom side of the screen on the same surface. But you will need to trim it down most likely- later Rollei screens are larger than the width of a 6x6 or 6x9 image.

I've tried differnt focus aids for setting infinity. I seem to keep coming back to plain ground glass. John Koehrer's suggestion to make your own is as good as any source.

When using the Yashica screen I used just the ground glass on the focal plain and left the fresnel lens to the side - as you said its too thick for a loupe and can throw off focus if used in the wrong order.

Managed to pick up a very cheap piece of regular ground glass instead from the same camera store for just £4 instead, its a little darker than the yashica glass but should be fine if I check focus in bright light!

 

[Ellyrion]

Howz about glass from a thrift store picture frame & grind it yourself,
It's not difficult at all. Maybe with 1000 grit or finer wet or dry sandpaper

Managed to pick up a very cheap piece of regular ground glass instead from the same camera store for just £4 instead, its a little darker than the yashica glass but should be fine if I check focus in bright light!

 

[Patrick Robert James]

Sounds like you might have not put the ground glass on the film rails. That would cause it to be too close to the lens and make it seem like it was focussing past infinity. Make sure your ground glass rests on the film rails.

 

[Ellyrion]

If the shutter block was removed and reinstalled, probably a good chance that a spacer is missing or bent or out of position. This will mess up the aperture dial. Some day, probably after your trip, you can try loosening the shutter block from the inside back of the lens board. Get it slightly loose, give it all a jiggle. While loose, see if the aperture dial is moving easier. On most shutters, the aperture lever is part of a large disk on the very back of the shutter- you might see the edge of this disk at the back of the shutter when installed. Serious binding is often from external pressure on this back disk, not from internal issues.

I'd use the camera for a bit. When you are up for it, you can remove the shutter block, reset the spacers and unjam the aperture dial. But then you are in for resetting infinity on the lens, and you've done enough of that for now! Once you spend some time with 6x9 negatives you'll possibly do this on a winter evening.

I've removed the shutter + lens assembly from the camera frame and you're bang on about pressure from the mountain plate making the aperture ring stiff - it works absolutely fine when detached! I've noticed that the aperture ring has some sort of gunk coating it on the side that would attach the the mounting plate (facing the camera) - I'm assuimg this was some sort of lubricant at one point but I'm thinking its part of the reason the ring is so stiff when mounted.

You reckon I should gently clean this old grease off with some lighter fluid or 99% Isopropyl alchohol? If so, should I be replacing it with something else? Thanks

 

[Dan Daniel]

(Sorry, away from computers for a bit). I would clean it off with a degreaser like alcohol or naphtha and leave it clean. THe gunk you saw was probably someone in the past thinking that dripping oil in there was a good idea, which it isn't. Every setup I have seen leaves this aperture ring clean of lubrication. It should move freely due to assembly, not due to lubrication.

You'll notice that the ring sits slightly below the inner ring which is the shutter body itself. If there are shims or washers between the shutter and the lens board, put the smaller diameter ones next to the shutter so that they sit on the inner ring and not overlap into the aperture ring area. Unless they are stiff metal. Also check the lens board for any ridges or lips that could bind.

 

[Ellyrion]

(Sorry, away from computers for a bit). I would clean it off with a degreaser like alcohol or naphtha and leave it clean. THe gunk you saw was probably someone in the past thinking that dripping oil in there was a good idea, which it isn't. Every setup I have seen leaves this aperture ring clean of lubrication. It should move freely due to assembly, not due to lubrication.

You'll notice that the ring sits slightly below the inner ring which is the shutter body itself. If there are shims or washers between the shutter and the lens board, put the smaller diameter ones next to the shutter so that they sit on the inner ring and not overlap into the aperture ring area. Unless they are stiff metal. Also check the lens board for any ridges or lips that could bind.

No worries at all! Thank you for your reply

I think you're right about the washer situation - I think I've found the issue. The reason the aperture selector is binding is the outer part of the selector (that sticks out so you can move it) is currently scraping along the edge of the lens board, which has raised edges. You can just make out the scratch mark that the selector dial makes along this raised edge in the photo attached.

I'm assuming that at some point there was a washer that went between the shutter and lens board as you said - on the lens board are two cutouts on the inner circle that I'm thinking must have locked the washer in place originally, as at the moment they dont lock into any part of the shutter when its mounted and seem to serve no purpose at all.

At the moment it seems I have three options:

1) Sand down the part of the edge of the lens board that is binding to the selector.

2) Find or make a washer so that the selector clears the edge of the lens board - Not quite sure how to go about this though

3) Return the Camera as I am pretty sure the seller must have lost the washer when he removed the lens to use on his DSLR, or it was missing in the first place. Either way, I'm fairly sure the camera is missing a crucial part as I cant see how this works without a washer involved - the cutouts seem to point towards one too.

Would love to hear your thoughts on how I should proceed!

Many thanks

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[Steve906]

No worries at all! Thank you for your reply

I think you're right about the washer situation - I think I've found the issue. The reason the aperture selector is binding is the outer part of the selector (that sticks out so you can move it) is currently scraping along the edge of the lens board, which has raised edges. You can just make out the scratch mark that the selector dial makes along this raised edge in the photo attached.

I'm assuming that at some point there was a washer that went between the shutter and lens board as you said - on the lens board are two cutouts on the inner circle that I'm thinking must have locked the washer in place originally, as at the moment they dont lock into any part of the shutter when its mounted and seem to serve no purpose at all.

At the moment it seems I have three options:

1) Sand down the part of the edge of the lens board that is binding to the selector.

2) Find or make a washer so that the selector clears the edge of the lens board - Not quite sure how to go about this though

3) Return the Camera as I am pretty sure the seller must have lost the washer when he removed the lens to use on his DSLR, or it was missing in the first place. Either way, I'm fairly sure the camera is missing a crucial part as I cant see how this works without a washer involved - the cutouts seem to point towards one too.

Would love to hear your thoughts on how I should proceed!

Many thanks

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Remember of course adding a washer will change your focus again, maybe why it was out in the first place if it was missing. Adding a thin washer or two would probably have been the best way to reset the focus issue assuming the lens itself had not been altered.

 

[Ellyrion]

Remember of course adding a washer will change your focus again, maybe why it was out in the first place if it was missing. Adding a thin washer or two would probably have been the best way to reset the focus issue assuming the lens itself had not been altered.

Oh definitely - I plan on recalibrating everything again once I've sorted this.

As for the washer that may be the case, although there was no way for me see the washer was missing initially so adjusting the front cell by a couple twists was the best route - the cell only rotates a small amount given the amount of thread so there is plenty of room for adjustment.

Focus isn't really the issue at the moment, it's very easy to adjust with the camera-collimator method (which is unbelievably precise as you're able to zoom right in with a digital camera, much better than ground glass imo if you have the option) and my last two rolls were sharp at all distances - just need to sort this selector switch out as otherwise it's a two-hand job to change apertures at lower values

 

[Steve906]

Oh definitely - I plan on recalibrating everything again once I've sorted this.

As for the washer that may be the case, although there was no way for me see the washer was missing initially so adjusting the front cell by a couple twists was the best route - the cell only rotates a small amount given the amount of thread so there is plenty of room for adjustment.

Focus isn't really the issue at the moment, it's very easy to adjust with the camera-collimator method (which is unbelievably precise as you're able to zoom right in with a digital camera, much better than ground glass imo if you have the option) and my last two rolls were sharp at all distances - just need to sort this selector switch out as otherwise it's a two-hand job to change apertures at lower values

That's what I would do - add a washer or shim of some sort cut from thin (.002") or so plastic, paper, foil or such to free the iris, then re-set the front cell using either of you methods as before. If it's a bit difficult cutting out a full circle just use three small pieces, sticking them to one side (just on that inner ring) with a tiny touch of grease while re-assembling.

 

[Ellyrion]

That's what I would do - add a washer or shim of some sort cut from thin (.002") or so plastic, paper, foil or such to free the iris, then re-set the front cell using either of you methods as before. If it's a bit difficult cutting out a full circle just use three small pieces, sticking them to one side (just on that inner ring) with a tiny touch of grease while re-assembling.

I Just tried this with some 1mm Styrene sheeting that I had just as a proof-of-concept and it works a charm! The seller had replied to me and said he is going to look for a spare washer that may fit, but otherwise I'll grab some steel shim sheeting (0.1 or 0.5mm) and play around and see what works. Will update in a few days with hopefully a working camera!

 

[Dan Daniel]

The packaging plastic used for batteries and such things- the clear parts- can make a nice shim material. Steve906's idea of making three sections, not a full circle, is good. You'll need to make the sections stick- glue or tape- for assembly.Bottle caps of assorted sizes are worth trying as templates for cutting- vitamin bottles or such might be the right diameters. Oh, the retaining ring!

The notches in the lens board are... well, I am not certain why there are two. Haven't seen that before. But one is for a pin on the back of the shutter to go into and stop the shutter block from rotating. Most likely the pin was removed by the previous owner and lost/forgotten. I see a hole in the back of your shutter that might be for a pin, but it looks as if it is 180 degrees off from the orientation on the lens board.