Vintage Lens Repair - Prinzflex (Chinon) 135mm f2.8 - Aperture Mechanism Strip Down - Retrotech
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- เผยแพร่เมื่อ 24 มิ.ย. 2020
- Having shown this Prinzflex 135mm f2.8 (actually a Chinon lens re-badged as a Prinzflex) lens in a previous video where we repaired a fault with the focusing mechanism and tested the lenses performance, I had a request from a viewer who had the same lens that they'd taken apart for repair but they couldn't remember how the aperture mechanism went back together, so they asked if I could do another video showing the back of the lens and the aperture operating mechanism. In this video you'll see the back end of the lens taken apart and put back together and then a few test shots at the end.
If you want to see the original repair and lens test video, you can see it here:
• Retrotech - Prinzflex ...
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High quality video. Thank you!
Cheers big3127, thanks for watching and commenting
Wonderful video, well done!
Cheers Stefano, it's fun making these videos and also learning stuff along the way.
Thank you so much for this. I bought an Auto Chinon version of this for a cheap price at a flea market but the aperture does not change when I depress the pin so something is not right inside the lens. Your video will at least help me to check what is going on inside.
Hi David, if the aperture doesn't move at all, it's possible that the aperture blades have got oil on them, which can make them stick. I haven't had to remove the aperture blades on one of these lenses - it tends to be a bit of a fiddly job, but not impossible, if you're careful. I had an issue on the 200mm Chinon lens where one of the springs attached to the static aperture control disk had come off - in that case the blades did move but they didn't operate correctly (I didn't film that fix).
Sometimes you can get away with cleaning oil off aperture blades while they're still in situ - you'd want to remove all the glass elements first and then using a cotton bud soaked in IPA or similar, VERY gently apply your IPA to the blades - once thy're moving, you can keep operating them by hand to re-distribute the oil and then clean again. You don't want to use force, because if you bend the blades, they won't work. The same goes if you have to remove the blades for cleaning, you don't want to bend them.
Cheers Tim, I notice you stopped before you got to taking lenses out. I presume because that doesn't help. I might have to give that a go on some cheap lenses.
I generally only take them apart if they need fixing - there's always a tiny risk that something will go wrong, and this lens is one that I actually use so I only wanted to go so far with it - hopefully that'll be enough to help the guy get his back together.
I've filmed (but not edited) another video where the elements needed cleaning so I'll get that one finished at some point - it's a slightly more modern Japanese lens with a few more elements inside and you need to be pretty careful getting them out because they can easily be re-inserted the wrong way round and it's not always that obvious when you re assemble the lens that something is wrong. It depends on exactly what that particular element corrects within the lens - with some of them you'll create a very "special effects" lens by reversing an element.
I generally buy cheap old lenses and fix them if required so I can use them - I don't film every fix because it takes far longer to do the work and it's really difficult working round the tripod and lighting!!!
Hi Tim, thanks for an excellent video on this section of the lens. Unfortunately, I recently purchased a Auto Chinon 135mm f2.8 lens which was sold as working in good condition and when I got it I saw the front element of the lens has tiny strands of fungus all around the edges. I wonder if you've ever opened the side with the built in hood and any advice on cleaning the optical elements to get rid of the fungus. Thanks. Dan.
Hi Dan, I did an earlier video on this lens where I took the front bezel off to tighten the screws that attach the focusing ring (which was slipping) you can see that video here: th-cam.com/video/uPnUMwpIXbU/w-d-xo.html - I didn't actually remove the front element but it looks like there's a metal lockring around the front element that needs to be unscrewed. Sometimes these are secured in place with a bit of lacquer or similar on the threads, making it almost impossible to unscrew, but usually a few drops of Acetone will usually soften that. You might need something like rubber kitchen gloves to grip the ring to undo it, or even a filter ring wrench of the correct size (these can be called many names - I usually make my own, as and when I need them, but if you search for "neewer filter ring wrench" you'll see the kind of thing I'm talking about). Thinking about it, I also made another video showing the cleaning of a 200mm Prinzflex lens which is pretty similar, you can see that one here th-cam.com/video/93Q3CyJzMuY/w-d-xo.html
As for cleaning the optics, you'll see in the 200mm video that I cleaned the optics, but not everyone is in approval of my techniques, particularly using tap water, which can contain small particles that will scratch the lens surface - it slightly depends on the lens you're working on, if it's a run of the mill lens that's already seen a bit of life and has a few scratches already plus lots of fungus, you're going to improve it even using the method I used, but for a better lens, more care might be required. I'm not planning to shoot any more lens cleaning videos because however you do it, there will be a hundred people who think you should do it differently, and some of them will be right. I'll throw you across to Vintage Optiks, who did a fungus cleaning video using Hydrogen Peroxide (which is the preferred choice among the greater photography community), but check out the comments to see lots of suggestions how he could have done it differently th-cam.com/video/czoisKjBCXY/w-d-xo.html
Hope that sort of helps, and have fun with your lens - they're a really nice, underrated lens and they get some great results too.
My Chinon copy has that plate covering the cams held in by very small screws along the chassis barrel, so I can't actually remove it. The aperture will close down if I push the semicircular tab to the right, and will open with the aperture ring, but will not close down again. I guess a spring somewhere is shot, since the semicircular thing isn't being pulled into that lever?
Hi Dane, it's so long since I looked at this lens I can't remember exactly how it worked in there. I do have a similar Chinon 200mm lens that had a problem with the aperture - that turned out to be a spring that had fallen off (no idea how the spring could fall off in normal use but it was off all the same), yours definitely sounds like there's a spring either broken/missing, or simply fallen off. If I get a chance I'll take a look and get back to you.
Additionally, if the aperture blades are covered in oil, or the mechanism is sticky, that will also cause the blades not to move as they should - the whole lot should move really freely, if there's too much friction the spring will not be able to close the blades.
@@GrumpyTim No worries. It's not worth paying someone to fix it for me (these lenses are surprisingly cheap) so I might just try to source a better condition copy. At least it works wide open for portraits.
Tim, you have spammers spamming your comments. I would suggest reporting them as spam and putting "InstaPwn" in your comment filter.
Cheers Benedict - those comments hadn't shown up in my "new comments" notifications. I'm forever reporting spam comments to TH-cam and they do nothing about them - just like the ones that people leave within minutes of uploading a video that have one word and a link - how come TH-cam's spam filters don't deal with them? Anyway, I've reported those and will add to my comment filter.
@@GrumpyTim They don't show up in new comments because they are replies, a deliberate tactic. Also, you appear to have got a lot of views on that video fairly quickly. Well done.
@@BensWorkshop Thanks for the heads up Benedict - I've added insta pwn to my blocked words list and I've also selected comments with links to be held for review - progress!!!
@@GrumpyTim Well done. Good work. Though that is one word not two....
@@BensWorkshop don't worry, I did it as one word - didn't know if it would block it in my own comment so I split it into two words.
Prinzreflex best lens in the world. I can't buy. It is not in my budget 😪😪😪
You can sometimes find the Prinzflex lenses really cheaply on ebay - in the UK anyway - Prinzflex was a brand name used by the Dixons group of shops but this particular lens was a Chinon lens re-badged so you could also search for one of those in case it was cheaper. Also, I've often found that lenses on their own cost more (on ebay) than buying one attached to an old film camera, so that can be an option. When some normality returns to the world, and we can go to boot markets/flea markets or whatever, there should be many more bargains to be found.