Internal Dust & Cleaning - Pentax-M 50mm/1.4

ManhattanProject · 08-15-2010, 01:51 PM

OK, so I did some searching, and I know this has been touched on a bit, but I guess I can't really find answers to exactly what I'm looking for, so here it goes.

I have a Pentax-M 50/1.4 I recently picked up really cheap. The glass is fine, but there is a decent amount of internal dust. The pictures it takes seem OK, but I have a couple questions.

- How much is the dust going to affect image quality?
- What are the chances that someone who has never disassembled a lens before can successfully disassemble, clean, and reassemble this thing so it works like new? It's not worth it to me to lose the lens altogether, for sure.
- Is there any definitive method for taking the lens apart for this? I've seen different guides related to A/M lens disassembling (none of which seem very concise), and they vary on whether to go through the front or the back to start.
- Any other useful advice that I may not have asked for directly also welcome.

Thanks in advance

hangu · 08-15-2010, 02:36 PM

It would take quite a bit of dust before you'd notice any degradation in image quality. You would have to take side by side images with a clean lens to notice any difference.

I would not bother with cleaning it if you don't notice any degradation in IQ. If you insist on doing so, though, it would require a spanner wrench, a 1.00mm precision slotted screwdriver and some sort of a circular rubber tool to remove the face plate if the dust is behind the front element.

danielausparis · 08-16-2010, 06:08 AM

A good idea is to first get acquainted on a crap garbage lens you can get for 5$ on the bay.

RioRico · 08-16-2010, 12:17 PM

Originally posted by danielausparis

A good idea is to first get acquainted on a crap garbage lens you can get for 5$ on the bay.

I resemble that remark.

One of my latest acquisitions is a brand-new US$5 lens in PK (M) mount. The front says 1:2.0 50mm AUTO LENS JAPAN 52(theta). The plastic body has an aperture ring and a focus ring with DOF scale. And that is ALL that is on the lens. No maker, no serial number, no nothing. Clean as a whistle, seems to render nicely. It's just totally anonymous. No, my fave junk lens is a Hanimex-Tokina 135/2.8 that is fogged beyond belief. At least it only cost US$3. All my five-buck lenses are better.

08-15-2010, 01:51 PM	#1
ManhattanProject Senior Member Join Date: Apr 2010 Location: Midwest Photos: Gallery Posts: 221	Internal Dust & Cleaning - Pentax-M 50mm/1.4 OK, so I did some searching, and I know this has been touched on a bit, but I guess I can't really find answers to exactly what I'm looking for, so here it goes. I have a Pentax-M 50/1.4 I recently picked up really cheap. The glass is fine, but there is a decent amount of internal dust. The pictures it takes seem OK, but I have a couple questions. - How much is the dust going to affect image quality? - What are the chances that someone who has never disassembled a lens before can successfully disassemble, clean, and reassemble this thing so it works like new? It's not worth it to me to lose the lens altogether, for sure. - Is there any definitive method for taking the lens apart for this? I've seen different guides related to A/M lens disassembling (none of which seem very concise), and they vary on whether to go through the front or the back to start. - Any other useful advice that I may not have asked for directly also welcome. Thanks in advance

08-15-2010, 02:36 PM	#2
hangu Veteran Member Join Date: Feb 2010 Location: NYC Photos: Gallery Posts: 1,071	It would take quite a bit of dust before you'd notice any degradation in image quality. You would have to take side by side images with a clean lens to notice any difference. I would not bother with cleaning it if you don't notice any degradation in IQ. If you insist on doing so, though, it would require a spanner wrench, a 1.00mm precision slotted screwdriver and some sort of a circular rubber tool to remove the face plate if the dust is behind the front element. Last edited by hangu; 08-15-2010 at 06:50 PM. Reason: god awful grammar errors

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08-16-2010, 06:08 AM	#3
danielausparis Forum Member Join Date: Dec 2009 Photos: Gallery Posts: 94	A good idea is to first get acquainted on a crap garbage lens you can get for 5$ on the bay.

08-16-2010, 12:17 PM	#4
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Originally posted by danielausparis A good idea is to first get acquainted on a crap garbage lens you can get for 5$ on the bay. I resemble that remark. One of my latest acquisitions is a brand-new US$5 lens in PK (M) mount. The front says 1:2.0 50mm AUTO LENS JAPAN 52(theta). The plastic body has an aperture ring and a focus ring with DOF scale. And that is ALL that is on the lens. No maker, no serial number, no nothing. Clean as a whistle, seems to render nicely. It's just totally anonymous. No, my fave junk lens is a Hanimex-Tokina 135/2.8 that is fogged beyond belief. At least it only cost US$3. All my five-buck lenses are better.

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