MFlenses - A new life in a digital age
MFLenses 2026

Manual Focus Lenses Forum

Explore the world of vintage lenses through repair notes, real test shots, and detailed archive threads packed with images.

Explore the world of vintage lenses through repair notes, real test shots, and detailed archive threads packed with images.
DiskFreeVault safely moves Mac apps and data to external storage.
Spotlight

Featured partner placement for the forum front page.

Repairing a smc pentax M 50/1.7
Post new topic Reply to topic
View previous topic :: View next topic  


Post
Posted: Wed Apr 11, 2007 8:25 pm
Post subject: Repairing a smc pentax M 50/1.7
Reply
Post
Posted: Wed Apr 11, 2007 8:25 pm
Post subject: Repairing a smc pentax M 50/1.7
Reply
This lens is in bad shape!

It has a big dent in the filter ring, because of this the focussing goes very stif?

Behind back and front element are signs of fungus.

I managed to sand of the side so focus works normal, then I made some tools to open the lens.

Now the question, what is the best way to clean the lenses, Maybe some lens cleaning spray for glasses or ???

Guido


Post
Posted: Wed Apr 11, 2007 8:32 pm
Post subject:
Reply
Post
Posted: Wed Apr 11, 2007 8:32 pm
Post subject:
Reply
I cleaned successfully many lens with 50 % Ammonium_hydroxide + 50% hydrogen peroxide mixture. Little smelly Smile , but kill fungus perfectly and clean the lens surface as well. Finish the cleaning with pure alcohol and micro fiber clothes.

Good if you have an lens sucker



http://www.micro-tools.com/Merchant2/merchant.mvc?LTPLanguage=EN&Screen=PROD&Product_Code=LS&Category_Code=LNS&Store_Code=MTE

Last edited by Attila on Wed Apr 11, 2007 8:35 pm; edited 1 time in total


Post
Posted: Wed Apr 11, 2007 8:32 pm
Post subject: Re: Repairing a smc pentax M 50/1.7
Reply
Post
Posted: Wed Apr 11, 2007 8:32 pm
Post subject: Re: Repairing a smc pentax M 50/1.7
Reply
Jigt wrote:

Now the question, what is the best way to clean the lenses, Maybe some lens cleaning spray for glasses or ???
Guido


No no no!!
No spray for goodness sake. I never cleaned lenses from fungus but based on what I read, a bath in a solution of vinegar in water is an effective way to kill the thing.

Afterwards, I would use the Eclipse product for cleaning the lenses. It is the only product I tried so far, that does not leave halos on lenses in at least 80-90% of cases.


Post
Posted: Fri Apr 20, 2007 11:36 am
Post subject: Help
Reply
Post
Posted: Fri Apr 20, 2007 11:36 am
Post subject: Help
Reply
Hello,

Could anyone help me with a manual/tutorial regarding the dismantle of a SMC Pentax M 1.7/50 lens. It has some fungus on it (front elements and back ones too sad ). Hope it doesn't have any elements fixed with glue.
I might buy one (Pentax 1.7/50 lens), but it has that problem with the fungus, so first I shall have to reach the lens.

Thank you very much.


Post
Posted: Fri Apr 20, 2007 12:26 pm
Post subject: Re: Help
Reply
Post
Posted: Fri Apr 20, 2007 12:26 pm
Post subject: Re: Help
Reply
montecarlo wrote:
Hello,

Could anyone help me with a manual/tutorial regarding the dismantle of a SMC Pentax M 1.7/50 lens. It has some fungus on it (front elements and back ones too sad ). Hope it doesn't have any elements fixed with glue.
I might buy one (Pentax 1.7/50 lens), but it has that problem with the fungus, so first I shall have to reach the lens.

Thank you very much.


Put up a picture with the lens maybe we come up with some ideas.
Sorin


Post
Posted: Fri Apr 20, 2007 12:39 pm
Post subject:
Reply
Post
Posted: Fri Apr 20, 2007 12:39 pm
Post subject:
Reply
Hello and thank you,

I do not have yet the pictures with the lens. I sent a request to the seller to send me the pictures. As soon as I receive the e-mail I shall post them.
Thank you again.

All the best.


Post
Posted: Fri Apr 20, 2007 5:45 pm
Post subject: Re: Repairing a smc pentax M 50/1.7
Reply
Post
Posted: Fri Apr 20, 2007 5:45 pm
Post subject: Re: Repairing a smc pentax M 50/1.7
Reply
Orio wrote:
...Afterwards, I would use the Eclipse product for cleaning the lenses. It is the only product I tried so far, that does not leave halos on lenses in at least 80-90% of cases.



I agree. The Eclipse cleaning fluid is great!


Post
Posted: Fri Apr 20, 2007 7:46 pm
Post subject: Re: Repairing a smc pentax M 50/1.7
Reply
Post
Posted: Fri Apr 20, 2007 7:46 pm
Post subject: Re: Repairing a smc pentax M 50/1.7
Reply
Jigt wrote:
This lens is in bad shape!

It has a big dent in the filter ring, because of this the focussing goes very stif?

Behind back and front element are signs of fungus.

I managed to sand of the side so focus works normal, then I made some tools to open the lens.

Now the question, what is the best way to clean the lenses, Maybe some lens cleaning spray for glasses or ???

Guido


As a fun excercise in taking a lens apart and having a mess about it should be good. Otherwise I think the best tool to help you is that container you keep outside the house. We call them dustbins!


Post
Posted: Sat Apr 21, 2007 12:16 pm
Post subject:
Reply
Post
Posted: Sat Apr 21, 2007 12:16 pm
Post subject:
Reply
Hello,

I found these:
http://homepages.ihug.co.nz/~Srawhiti/pentax50mmf1.4.html
http://www.pentax-manuals.com/manuals/service/servicemanuals.htm

Hope I'll manage to clean it if I'll buy it.


Post
Posted: Sun Apr 22, 2007 5:56 pm
Post subject:
Reply
Post
Posted: Sun Apr 22, 2007 5:56 pm
Post subject:
Reply
Thanks all,

The first clean is done and the first pics are made.

Its a succes, the fungus behind the front element ist not cleaned yet.

becausse of the damage of the filter tread i can't open the lens.


Guido


Post
Posted: Sun Apr 22, 2007 7:38 pm
Post subject: quick result
Reply
Post
Posted: Sun Apr 22, 2007 7:38 pm
Post subject: quick result
Reply
Quicly made before dark!

both shots wide open




Guido


Post
Posted: Sun Apr 22, 2007 7:44 pm
Post subject:
Reply
Post
Posted: Sun Apr 22, 2007 7:44 pm
Post subject:
Reply
Yes, seems a good lens!


Post
Posted: Sun Apr 22, 2007 8:01 pm
Post subject:
Reply
Post
Posted: Sun Apr 22, 2007 8:01 pm
Post subject:
Reply
Those linden leaves are beautifully detailed.


Post
Posted: Sun Apr 22, 2007 9:28 pm
Post subject:
Reply
Post
Posted: Sun Apr 22, 2007 9:28 pm
Post subject:
Reply
Orio wrote:
Those linden leaves are beautifully detailed.


For a lens with fungus this is a remarkable picture. It makes you wonder if it's worth worrying about a little fungus Confused

In England this tree species (Tilia) is called a Lime. I never understood the logic for this, because the Lime fruit comes from a completely different species (Citrus).

Did you know that new, light green Linden leaves are good to eat as salad?


Post
Posted: Sun Apr 22, 2007 9:49 pm
Post subject:
Reply
Post
Posted: Sun Apr 22, 2007 9:49 pm
Post subject:
Reply
Nice, seems to work Smile

To stop the fungus from getting worse, you might want to try and kill it. You can do this by putting the lens straight up on a piece of aluminium foil with the caps removed on a sunny day.
Leave it there for a whole day and you should be good. The sun reflects on the foil and the UV kills the fungus inside the lens.

(some say you best wrap up the outside of the lens in foil too, to avoid it getting too hot and elements getting out of place)


Post
Posted: Sun Apr 22, 2007 9:52 pm
Post subject:
Reply
Post
Posted: Sun Apr 22, 2007 9:52 pm
Post subject:
Reply
TDN wrote:
Nice, seems to work Smile

To stop the fungus from getting worse, you might want to try and kill it. You can do this by putting the lens straight up on a piece of aluminium foil with the caps removed on a sunny day.
Leave it there for a whole day and you should be good. The sun reflects on the foil and the UV kills the fungus inside the lens.

(some say you best wrap up the outside of the lens in foil too, to avoid it getting too hot and elements getting out of place)


I tried this way to kill fungus, didn't helped.


Post
Posted: Tue May 08, 2007 8:40 pm
Post subject:
Reply
Post
Posted: Tue May 08, 2007 8:40 pm
Post subject:
Reply
i've tried it and it works great. guess it's our god hot Texas sun.
i just broke down a smc M50/2. it was a piece of cake.

filter ring can sometimes be aligned by taking a jigsaw and cutting into a piece of wood the correct diameter in it for the lens in question. place the bent part in the cut out and using a wooden dowel placed on the bend and lightly striking the dowel with a hammer. best done with two people.


Post
Posted: Tue May 08, 2007 8:51 pm
Post subject:
Reply
Post
Posted: Tue May 08, 2007 8:51 pm
Post subject:
Reply
Like all earth creatures fungus need oxygen, so deprive them of oxygen, deep bath the lenses in pure vinegar for at least one day, this is reported to work, otherwise Attila can give you his chemical recipe which will be even more aggressive.

On a slightly different subject, a popular remedy here ro remove fungus attacking pans and cups due to non perfect washing and/or storing in dark closets, is to use vinegar. Housewomen have used this for centuries so it must have some validity Wink


Post
Posted: Thu Oct 04, 2007 11:04 am
Post subject:
Reply
Post
Posted: Thu Oct 04, 2007 11:04 am
Post subject:
Reply
Hi,

Attila wrote:
I cleaned successfully many lens with 50 % Ammonium_hydroxide + 50% hydrogen peroxide mixture.


Would you please give us the respective concentration of ammonium hydroxide and hydrogen peroxide ?

Thanks !!


Post
Posted: Thu Oct 04, 2007 11:59 am
Post subject:
Reply
Post
Posted: Thu Oct 04, 2007 11:59 am
Post subject:
Reply
Highest available in special shops don't know exactly higher than household ammonia.


Post
Posted: Thu Oct 04, 2007 12:25 pm
Post subject:
Reply
Post
Posted: Thu Oct 04, 2007 12:25 pm
Post subject:
Reply
For sure Wink

I will ask to my pharmacist.
Post new topic Reply to topic
Page 1 of 1