I bought one of these disassembled for 15€ since the previous owner couldn't figure out how to put it back together. Thanks to you I saved over 50€ on buying this lens, couldn't have done it without you

Fantastic video! Very helpful, thank you very much!

Note: my Chinon had 3 screws holding the front ring on it's sides. Loosing them is mandatory if you've got the same construction. Unscrewing the front barrel is easy if done so

Thanks this is a great video! However I’m struggling to remove the retaining ring that holds the front element and second element in place (I’ve cleaned everything else), do you have any tips on opening it?

@FocalReduced

Жыл бұрын

Retaining ring are usually held in place with adhesive. Use a small amount of isopropyl alcohol to soften the adhesive.

Is it possible to remove the Front element? or is it cemented? Im cleaning a Yashica Auto-Yashinon-DS 50mm f1.4 which has the same construction Layout

@FocalReduced

Жыл бұрын

Yes it is possible to remove the front element.

Maybe you can help, i have Vivitar 50mm (Pentax-K mount) with helicoid construction which looks similar, and in my case screws which hold focus ring were little unscrewed and i accidentally separate internal part of helicoid from other part of lens (by focusing too short of course, and of course no marks to put it back correctly). I put back all parts, but i don't know if i do it correctly, can it be so, that part made from yellow metal will be rotated incorrectly (as i understand it has multi-start thread inside and also some thread outside? So should that yellow part move forward-backward on thread when rotating? or it should be screwed till end (looks like that thread has much smaller step and maybe should not have impact, or it should be used?

@FocalReduced

Жыл бұрын

The brass portion of the helicoid should not be screwed all the way. There needs to be some space for adjustments. If the lens can focus to infinity and the distance scale is accurate, than you have a good working lens.

@Ivan33120

Жыл бұрын

@@FocalReduced Thanks for answer, I've tried to adjust focus ring to infinity on Pentax camera (i leave a small space after infinity, for case if i adjust with some error), but when i put lens on camera with MFT via converter, i've got much more space till end of focus ring (maybe it's a converter problem, or maybe i need to adjust focus ring better)... But ok, if I understand correctly from your answer if lens focusing ok on all distances then mostly everything ok.

@Ivan33120

Жыл бұрын

@@FocalReduced Oh, and don't you know, is there any way to prevent skrews which are holding focus ring from self-unscrewing during work?

@FocalReduced

Жыл бұрын

Most adapters/converters are manufactured slightly short to make sure that infinity focus is achieved. This means that most lenses will focus past infinity. It sounds like your lens is functioning properly. As for the screws, manufacturers used to add a drop of adhesive on top of the screw so that it will not back out. Just make sure its a rather weak adhesive, in case you need to disassembly the lens again.

@Ivan33120

Жыл бұрын

@@FocalReduced Thanks for answer

I’m new to your channel. Your video is so good that I’m convinced I should not attempt to fix my copy of the Yashinon DS 50mm f1.7. Focus is stiff toward the infinity mark and requires a lot of effort. Possibly a previous owner tried to do the repair themselves. How do I find a reputable repair shop? Is that something you do? Thanks.

@FocalReduced

4 ай бұрын

Thank you for your feedback. Many repair shops have called it quits in regards to lens repair. This is mainly due to labor prices. It will almost be always more affordable to buy a good condition copy of a lens that is quite common, than to have the lens repaired. More rare lenses are a different story however.

@baggerrider8073

4 ай бұрын

@@FocalReduced Thank you so much for your reply. The focus is only stubborn near infinity. I pretty much use all my M42 lenses for fairly close subjects and would probably never use this particular lens at infinity. It’s the only vintage M42 lens I’ve purchased that wasn’t from a reputable seller and shipped to me CLA’d. I bought it for its Tomioka connection and yellow aging. It’s really an excellent lens in all other ways. So I’ll probably just use it as is. It bothers me that it’s not “perfect”, but neither am I. lol.

@baggerrider8073

4 ай бұрын

@@FocalReduced I just checked the lens at infinity. It actually goes past infinity by 1/4” or so. What is involved in correcting infinity? I would appreciate your advice.

@FocalReduced

4 ай бұрын

In most cases, this is normal. They calibrate the focus to go past the infinity mark because temperature can effect the metal. Also, if you are using the lens with an adapter, on a modern digital camera, the manufacturer of the adapter will deliberately make the adapter shorter, so that infinity focus is guaranteed.

@baggerrider8073

4 ай бұрын

@@FocalReduced Yes I’m using the lens with a K&F M42-Fuji X adapter. It was interesting because I unscrewed the front ring and it sounded like there was grit inside. Once I unscrewed the ring, without pushing the element out, I was able to blow out the sand. No surprise because I bought the lens from a gentleman who lived on the California coast! Much smoother focus now.