Summaron 3.5cm/f3.5 front lens block loose/rotating

[nikstanbridge]

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Ok, I did a dumb thing… I idly checked if could undo the UVa filter without holding the lens barrel. The entire front section (optical block) that includes the aperture ring simply unscrewed. I obvs didn’t undo/remove it, but carefully, lightly hand tightened it again.

I managed to tighten it and get the aperture ring dot to line up with the focus ring dot but haven’t been able to get the aperture numbers to correctly ’sync’ with their dot. I’m not too worried about this though as I have the same issue with my Summitar without any practical issues. 

Focussing is as smooth as ever… but, will my images still be in focus? I’m on a trip and can’t get the lens fixed/CLAd until my return (several months). Should I park it until I get back or is it safe to use? How do I know if I’ve tightened it enough/too much?

[fabianoliver]

Hi, i've dismantled mine a month ago, they're good build lenses.

I've a Summitar as you with the same problem times to times, it becomes loose, and if i tight it too mutch i cannot change diaphragm.

If i was in your situation, i'll keep shooting without stress, tight it firm but not too mutch, if it continues to change diafragm good you are set.

Enjoy the trip, and the lens.

 

 

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[hmzimelka]

12 hours ago, nikstanbridge said:

Ok, I did a dumb thing… I idly checked if could undo the UVa filter without holding the lens barrel. The entire front section (optical block) that includes the aperture ring simply unscrewed. I obvs didn’t undo/remove it, but carefully, lightly hand tightened it again.

I managed to tighten it and get the aperture ring dot to line up with the focus ring dot but haven’t been able to get the aperture numbers to correctly ’sync’ with their dot. I’m not too worried about this though as I have the same issue with my Summitar without any practical issues. 

Focussing is as smooth as ever… but, will my images still be in focus? I’m on a trip and can’t get the lens fixed/CLAd until my return (several months). Should I park it until I get back or is it safe to use? How do I know if I’ve tightened it enough/too much?

The optical block should not have unscrewed. That's all held in place through other means. 

The silver ring in front of the aperture ring can be unthreaded to reveal three more screws behind it holding the aperture ring in place. 

The front silver ring you unscrewed is held in place with a grub screw when its correctly positioned to match up with the clicked aperture numbers.

See the images below. The lens' front black ring between the nameplate and the front element can be unthreaded . I use a rubber cone tool which can be seen in the top image. Even an eraser could work to remove this ring.

This should reveal the grub screw. Make sure it's unscrewed a little, position the ring properly in place to align with the apertures and then righten the grub screw. Just finger tight. These screws shouldn't be very tight.

 

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Edited September 23, 2023 by hmzimelka

[nikstanbridge]

8 hours ago, fabianoliver said:

Hi, i've dismantled mine a month ago, they're good build lenses.

I've a Summitar as you with the same problem times to times, it becomes loose, and if i tight it too mutch i cannot change diaphragm.

If i was in your situation, i'll keep shooting without stress, tight it firm but not too mutch, if it continues to change diafragm good you are set.

Enjoy the trip, and the lens.

 

 

Thanks for the reassurance - that’s my plan… carry on and get it properly sorted when I get back. 

[nikstanbridge]

2 hours ago, hmzimelka said:

The optical block should not have unscrewed. That's all held in place through other means. 

The silver ring in front of the aperture ring can be unthreaded to reveal three more screws behind it holding the aperture ring in place. 

The front silver ring you unscrewed is held in place with a grub screw when its correctly positioned to match up with the clicked aperture numbers.

See the images below. The lens' front black ring between the nameplate and the front element can be unthreaded . I use a rubber cone tool which can be seen in the top image. Even an eraser could work to remove this ring.

This should reveal the grub screw. Make sure it's unscrewed a little, position the ring properly in place to align with the apertures and then righten the grub screw. Just finger tight. These screws shouldn't be very tight.

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Thanks for the detailed info. I’ll maybe have a go at this when I get back from the trip when I have access to tools. 

[nikstanbridge]

4 hours ago, hmzimelka said:

The optical block should not have unscrewed. That's all held in place through other means. 

The silver ring in front of the aperture ring can be unthreaded to reveal three more screws behind it holding the aperture ring in place. 

The front silver ring you unscrewed is held in place with a grub screw when its correctly positioned to match up with the clicked aperture numbers.

See the images below. The lens' front black ring between the nameplate and the front element can be unthreaded . I use a rubber cone tool which can be seen in the top image. Even an eraser could work to remove this ring.

This should reveal the grub screw. Make sure it's unscrewed a little, position the ring properly in place to align with the apertures and then righten the grub screw. Just finger tight. These screws shouldn't be very tight.

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

The big question though is whether it’s safe to use in its current, seemingly right/stable state?

[hmzimelka]

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1 hour ago, nikstanbridge said:

The big question though is whether it’s safe to use in its current, seemingly right/stable state?

Yes, if the large front ring is snug (finger tight), and the black conical ring holding in the name plate is too, then it's fine to use. It would suck if you loose the black conical ring and nameplate because they may be loose. 

Just out of interest, when you tighten the large ring, does the black dot on the ring overshoot or undershoot the set aperture lines?

 

Edited September 23, 2023 by hmzimelka

[nikstanbridge]

1 hour ago, hmzimelka said:

Yes, if the large front ring is snug (finger tight), and the black conical ring holding in the name plate is too, then it's fine to use. It would suck if you loose the black conical ring and nameplate because they may be loose. 

Just out of interest, when you tighten the large ring, does the black dot on the ring overshoot or undershoot the set aperture lines?

 

Yes, everything is finger tight and the silver ring/conical ring is also tight (or rather, it’s not loose). 

Not sure which way is under/overshooting but when I tighten the large ring to get the aperture ring dot to line up with the focus ring dot, the aperture numbers are skewed to the LH aside of the lens looking at it from the front. So f3.5 is at ~10 o’clock not 12. Hope that makes sense.

[hmzimelka]

1 hour ago, nikstanbridge said:

Yes, everything is finger tight and the silver ring/conical ring is also tight (or rather, it’s not loose). 

Not sure which way is under/overshooting but when I tighten the large ring to get the aperture ring dot to line up with the focus ring dot, the aperture numbers are skewed to the LH aside of the lens looking at it from the front. So f3.5 is at ~10 o’clock not 12. Hope that makes sense.

By undershoot I meant that the ring would need more tightening to accurately represent the notched aperture setting. That when your aperture ring is in the wide open notch, the dot would be lined up somewhere between f/4 and f/3.5. 

Easiest would be to set your aperture to f/5.6 or f/8, and then tighten the ring to match. If the tightening feels a little scratchy, then leave it, since that may indicate the grub screw is contacting the inner threads. Ideally when you have the tools and the time, see what happened to the grub screw and whether its loose or missing. 

I inherited my Sumamron 3.5cm f/3.5, and it's been "serviced" before, and poorly at that. I found missing screws, one screw had a stripped thread, and other witness marks inside. I managed to clean and grease the helicoids, but the lens isn't perfect. Hopefully yours is in much better condition inside and that the grub screw probably just got a little loose. 

BH Photo sells the rubber cone lens tool that will help with the removal of the black conical ring. 

https://www.bhphotovideo.com/c/product/1223685-REG/japan_hobby_tool_jht9520_vacuum_pad_for_camera.html