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01-15-2020, 06:30 PM - 2 Likes   #16
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Hello,

Pentax M 50 f1.4

Before:




During:


After:








Samples with it:






Thanks,

01-15-2020, 07:52 PM   #17
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Loving these before and afters!
01-16-2020, 03:15 PM - 1 Like   #18
Des
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QuoteOriginally posted by carabez Quote
I have a Pentax M 50mm f2 (dust and fungus) that I want to transform into a Soft lens by sanding some elements.
@Dartmoor Dave; tried this with an 18-55. He didn't think it made a big difference until he took off all the coatings using silver polishing cloth: See:The K10D Club! - Page 35 - PentaxForums.com (and the follow-up discussion on that page), The K10D Club! - Page 46 - PentaxForums.com and The K10D Club! - Page 47 - PentaxForums.com
01-16-2020, 05:50 PM - 3 Likes   #19
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Hello,

This one has an interesting story: Back in 2011 I was at the photo lab talking to the owner. We were looking for some old lighting equipment and somehow we ended up in a small storage room behind the storage room, behind the studio, behind the store. Something like an attic within the attic. You get the idea. In there, I found a pile of dust that resembled a lens. It was this dented old Vivitar screwmount 135mm f2.8. He said I could take it if I wanted since it was pretty much useless and it may have been there for many years.
Back home I dusted it off and noticed some fungus inside. However, the dent was quite severe. It must have been quite a hit.

Before:


During:


After:




Sample images with it:






You can read the story here:
Restoring an old m42 lens - PentaxForums.com

Thanks,

01-17-2020, 02:13 AM - 8 Likes   #20
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QuoteOriginally posted by Des Quote
@Dartmoor Dave; tried this with an 18-55. He didn't think it made a big difference until he took off all the coatings using silver polishing cloth: See:The K10D Club! - Page 35 - PentaxForums.com (and the follow-up discussion on that page), The K10D Club! - Page 46 - PentaxForums.com and The K10D Club! - Page 47 - PentaxForums.com

Yes, it turned out that you have to sand the heck out of a front element to see much of a difference at all. Here's the 18-55mm after sanding but before I polished off the coating:



And a couple of snaps after sanding and with the coating polished away as far as was possible:






But my favourite "lens back from the dead" is my 1947 Kodak Anastigmat 50mm/3.5 that I took off a broken Kodak 35RF rangefinder and converted to K mount, thanks the the coincidence that the flange lengths are close enough for it to work. Here it is on a K100D:



And a couple of snaps using it on the Samsung GX-10 version of the K10D (it's by far the sharpest 50mm I own):





01-17-2020, 05:46 PM   #21
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Love that Kodak lens in the K100D!
01-18-2020, 05:25 AM - 3 Likes   #22
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Hello,

Here is one of my earliest from over 10 years ago. Pentax A50 f2

Before:


During:


After:


Sample image SOOC:


Thanks,
01-19-2020, 06:45 PM   #23
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Loving these stories.

01-19-2020, 07:31 PM - 3 Likes   #24
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Hello,

Here is my latest one to date. About a month ago (Dec '19) I got one of those ebay gambles: An "as-is" K1000 with a Sigma 35-70 f2.8-4. The ebay pictures were pretty bad. The K1000 was cleaned and it is ready for testing. But the lens was very dirty and had some fungus inside. I honestly thought it was a throw away, not even worth keeping even as a body cap. So I did not bothered to take pictures of it as received. Took it apart and I was able to get to all groups. Cleaned it with hydrogen peroxide and it turned out better than I expected! I had noticed it was focusing way past infinity before so when I put it back together, slightly adjusted it to better match the distance scale. Finally, a deep cosmetic clean outside. Bottom line, it turned out way better than I expected.

After:








I usually test with my trusty K100DS but I had the K-01 handy. Slapped it and did a quick test:




Tested with the K100DS. These are 1:24 scale diecast parts donors from my other hobby: Scale modeling. With proper post process (sharpening, contrast) this lens can deliver.

@35mm focal lenght


@70mm focal lenght


A true left for dead, almost thrown away lens...

Thanks,
01-21-2020, 01:50 PM   #25
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I tried reviving my 58mm f/1.4 MC-Rokkor which looked hazed, but when I opened it up, the coating on one of the lens elements looked like at was no longer smooth, even though there was no sign of fungus. Cleaning with IPA did nothing, so I assume it can't be revived unless someone has a bright idea on how to proceed.
01-22-2020, 12:25 AM   #26
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Sholom if Inhave done three of these. The front element is often the problem. But I have one right now where the second and third elements from the front ( the ones that are at the rear of the front lens sub assembly ) also have bad haze.

Firts one I did cleaned up fine with a longish soak in IPA, from memory it had anout an hour in an IPA bath. Second one was a horrrible but a quick hit with a dilute acetone cleaned it off. Rokkor are reputed to have weak coayings that can be damaged by IPA but the ones I have worked on have never exhibited any bad response.

The ancient Tak I am working on may be similar to what you describe. Initially the front element was super hazy and had a texture to the eye like an orange peel. It felt smooth but under a strong light it had a speckly look tonthe super bad haze plus itbhad very bad fungus around its edges. The issue was on its back face.

The only thing that shifted whatever it was on the front of this lens was acetone which will carry a risk to the lens and coatings.
01-26-2020, 12:53 PM - 2 Likes   #27
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My own prophecy about Minolta coatings come true - yesterday I started work on two Minolta MC lenses. A 35mm HG 2.8 and a 58mm PF 1.4. The 35 was an oddball as its guts are similar but not identical to an SR Auto Rokkor but the barrel and some of the interior is more like an MCII but not quite. Its neither wholly MCI or MCII. Simple to fix as these things are a horror for oiling up the apertures. That bit was easy but the lens faces were badly contaminated and nothing seems to make them really good. They look fine to the naked eye but put a torch on it and it looks bad. I have put this aside for further investigation.

All day today, and most of yesterday too, I have been hard at it with the 58mm. Its been a complete nightmare- like the Pentax lens in my 'HELP' thread it looked like it had been in a ditch for the past few years. Everything was either gummed with oil or covered in filth. I have had to take it back almost to its molecules to get it back together. Anti-reflection. coating on the back surface of the front lens (which according to what I read is a magnesium base) had been partly eaten away and the IPA reacted badly with the rest of it. Had to be cleaned off with acetone to remove what was left. So.....acetone will quite deffo remove a Minolta coating (that kiddies is your lesson for today ) its only taken maybe 6 hours to get the front element clean and looking good. Every element has been dosed with peroxide and IPA and polished, all the interior elements were hazed with what I assume to have been dried oil plus some fungus happily eating things. Aperture soaked off in IPA, focus helicoids cleaned out with methalyated spirits and the all other parts left in hot soapy water with commercial washing powder with bleaching agents in - as this lens is never going to be great I have chosen to use it as a test vehicle for some processes hence the washing powder which should annihilate fungal spores - we'll see. Its then been washed out with clear water, lenses washed with distilled water, left to try, all surfaces polished to perfection and then reassembled, helicoids greased and aperture ring cleaned out.
I never get round to taking many pics as I tend to get absorbed in what I am doing (I suffer mild OCD and it can be a bugbear times - on the other hand it leads to perfection often).

Anyway just finished this -how Ismael find the time to do this as often as he does baffles me. This lens has pretty much had a whole solid two days of work put into it and I am now exhausted not even eaten all day.

Heres some pics of it in pieces and one of the finished product - when I started yesterday looking through it was like looking through frosted glass smeared with oil, focus was jammed and the aperture non-reactive plus the aperture ring was jamming at fully closed and fully open.
Attached Images
View Picture EXIF
DMC-TZ70  Photo 
View Picture EXIF
DMC-TZ70  Photo 

Last edited by Astro-Baby; 01-26-2020 at 01:04 PM.
01-26-2020, 02:13 PM   #28
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Hey that's a topic suited for my tinkerings !
Hello.

I just finished a CLA on a SMC Takumar 135mm f/3.5 yesterday (fungus everywhere, sluggish diaphragm). That was a bit hard, as I did not understand at first how the lens was assembled and working. I'm more a Carl Zeiss Jena and Meyer Optik maniac. I ended up disassembling it even more, then cleaning and re-lubing focussing helical, and the diaphragm ring, because I had hastily sprinkled the diaphragm with petroleum ether thinking it will do a quick and dirty fix. This dissolved and spread grease. Ended up more dirty than quick, so I had to go through all the steps finally.


Two day ago, I cleaned the fungus infestation of a Pentax-A 24mm f/2.8. There's some stains left on SMC coating where the fungus was, but the lens is clear now.

Three days ago I fixed an inoperative diaphragm on a Pentax-M 28mm f/2.8 .

I've done some more earlier.

I like fixing lenses back to usability. But did not take before/during/after photos.
Now I need documenting my work in order to participate here !

Last edited by Praktica*ist; 01-26-2020 at 02:35 PM.
01-26-2020, 03:01 PM   #29
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QuoteOriginally posted by Astro-Baby Quote
how Ismael find the time to do this as often as he does baffles me.
HA! That is my eternal complaint: I don't have time!
The truth is you are looking at a span of about 10-12 years in these posts of mine.

Thanks,
01-27-2020, 12:10 PM   #30
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Hi Ismael, at the risk of taking this thread off topic do you have any suggestions for my Minolta 35mm. The front lens has what looks like cleaning marks. They look like overlapping patterns of water marks with a speckled overlay, the speckles look like dust but arent, they are some kind of dried deposit or possibly pitting. i incline to dried deposits though, they are very, very fine. Nothing seems to make either the watermark looking stuff or the speckles go away. I have tried a wipe with acetone, a soak in peroxide at very high concentrations, soaking in IPA a 12 hour soak in just water witn mild detergent and nothing makes any difference. I dont want to risk a soak in acetone in case it rips the coating off which I am sure it will. I am planning a long overnight soak in a stronger commercial detergent with a very mild bleaching agent but frankly I cant see it working. As you are the lens whisperer I wondered what you might use.
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