[Wild Mark]

I have a few K1000s with prism desilvering. Under directions I have successfully used Spotmatic F prisms to replace desilvered K1000 prisms. But I have exhausted my supplies there.

I sense the Spotmatic SP2 is the same as the F and K1000 with respect to prisms. Can anyone confirm this? Also, can anyone comment on the ES and ESII as possible prism donors for the K1000.

Thanks in advance

[boriscleto]

Why? Are these parts only Spotmatics? I can't even imagine cannibalizing a Spotmatic for a K1000...

[stevebrot]

Why? Are these parts only Spotmatics? I can't even imagine cannibalizing a Spotmatic for a K1000...

The only reason I might think of is if one is seeking to take advantage of the inflated prices often commanded by K1000s by harvesting prisms from junk.

$10 "parts only" Spotmatic + $20 clean, but desilvered K1000 ==> $200 K1000

The big question is whether the prisms are really identical. The Spotmatic part number is #12004. I don't have a parts list for the K1000.


Steve

[AstroDave]

Are they really silvered, or aluminized? Maybe you could re-"silver" your existing mirrors: if aluminum would work (worth a try?), try to find a local amateur telescope maker (or telescope club) - they should have some experience in depositing thin reflective films on glass or at least know where to get it done.

[Wild Mark]

The only reason I might think of is if one is seeking to take advantage of the inflated prices often commanded by K1000s by harvesting prisms from junk.

$10 "parts only" Spotmatic + $20 clean, but desilvered K1000 ==> $200 K1000

The big question is whether the prisms are really identical. The Spotmatic part number is #12004. I don't have a parts list for the K1000.


Steve

In short, yes.

Should i be ashamed? No - Spotmatics are laying around everywhere unused yet K1000's are in demand. I see no problem with resuscitating old with old to serve a revived interest

[stevebrot]

In short, yes.

Should i be ashamed? No - Spotmatics are laying around everywhere unused yet K1000's are in demand. I see no problem with resuscitating old with old to serve a revived interest

Truly, what you are doing is no different than what is done by used camera shops the world over. Where things get complicated is when the general supply of used parts and repairable used cameras becomes more dear for what should be more desirable models. Scavenging a fairly rare Spotmatic F* or even a more common KM in working or salvageable condition to fix a common-as-crows, made-in-China** K1000 tends to ruffle feathers on a fan site, so be prepared for some push-back. OTOH, using a compatible "parts only" body as a generic donor makes perfect sense to me if the parts are truly the same. Even better is if the body is fully parted out. When/if you are able to confirm common part numbers for the prisms, please share the information. It will be useful in general.


Steve

(...have noticed a severe decline in usable film cameras here locally in the last year or so...have also noticed that prices for working Spotmatics in good condition is rising...)

* I say fairly rare because I have never seen one in the wild or in a shop despite a decade or so of scouting around for that kind of thing.

** The prism desilvering issue seems to be limited to later production K1000, specifically those produced in China.

[Wild Mark]

Truly, what you are doing is no different than what is done by used camera shops the world over. Where things get complicated is when the general supply of used parts and repairable used cameras becomes more dear for what should be more desirable models. Scavenging a fairly rare Spotmatic F* or even a more common KM in working or salvageable condition to fix a common-as-crows, made-in-China** K1000 tends to ruffle feathers on a fan site, so be prepared for some push-back. OTOH, using a compatible "parts only" body as a generic donor makes perfect sense to me if the parts are truly the same. Even better is if the body is fully parted out. When/if you are able to confirm common part numbers for the prisms, please share the information. It will be useful in general.


Steve

(...have noticed a severe decline in usable film cameras here locally in the last year or so...have also noticed that prices for working Spotmatics in good condition is rising...)

* I say fairly rare because I have never seen one in the wild or in a shop despite a decade or so of scouting around for that kind of thing.

** The prism desilvering issue seems to be limited to later production K1000, specifically those produced in China.

If I manage to find out the part numbers I will definitely share. It would be very useful for everyone to know.

As for sacrilegious behaviours (in the eye of a 'fan') all I can say is guilty as charged. But the reality is there are fewer and fewer parts available for these old cameras (including K1000's) and one has to improvise. On that note, my observations are:

- Spotmatic F prisms are vulnerable to desilvering. Two of mine have this problem.
- KM prisms are vulnerable to desilvering too. It might be 20% of the cameras I have/ had that were inflicted.
- Non Chinese K1000 prisms have a lower rate of desilvering than the Chinese models. Appears to be a similar rate to the KM prisms.

Desilvering is an inevitable outcome for these parts. The glue and foam attached to the prisms deteriorate and fall off. IN so doing, it may take away the attached silvering thus degrading the prism. Nothing will stop this process with age of camera probably enhancing the prevalence. On this basis, there will be a major shortage of prisms in the foreseeable future as repairs such as those I propose eat away at the bank of spare parts available in old bodies.

The real solution to this problem is getting prisms made for these ailing cameras. On that score, my interim thought is to keep the damaged prisms and consider restoration - I am actually seriously considering this step as I type but cost will be an issue.

[stevebrot]

The real solution to this problem is getting prisms made for these ailing cameras. On that score, my interim thought is to keep the damaged prisms and consider restoration - I am actually seriously considering this step as I type but cost will be an issue.

There may be a market beyond just Pentax. The idea is intriguing.


Steve

[ctrout]

Here's a good start. These guys say that they can resilver anything made of glass.
resilvering | Bear Glass a full glass fabricator in USA.

I also found the silvering solutions online. I'll bet that if you were doing 2-3 prisms, getting it done would be best. If you were going to do 10+ prisms, you might think about trying to do them yourself. The silvering solution alone, not including the other necessary chemicals, is over $500 for one pint. Google Peacock Labs.

[ChrisPlatt]

I'd be really impressed to see a Spotmatic F converted to PK bayonet mount.
If it focused to infinity and retained open-aperture metering I'd buy two.

Chris

[ctrout]

I'd be really impressed to see a Spotmatic F converted to PK bayonet mount.
If it focused to infinity and retained open-aperture metering I'd buy two.

Chris

It's called the Pentax KM.

[Wild Mark]

Here's a good start. These guys say that they can resilver anything made of glass.
resilvering | Bear Glass a full glass fabricator in USA.

I also found the silvering solutions online. I'll bet that if you were doing 2-3 prisms, getting it done would be best. If you were going to do 10+ prisms, you might think about trying to do them yourself. The silvering solution alone, not including the other necessary chemicals, is over $500 for one pint. Google Peacock Labs.

A restoration project for a bulk order of prisms would be a cost efficient way forward. It would take some organising. I think I have about 10 prisms already with such needs (K1000, K2, Spotmatic F).

[ChrisPlatt]

It's called the Pentax KM.

Functionally yes, but not really. With the K series IMO the quality was already diminishing.

FWIW I do own two serviced Pentax KM bodies.

Chris

[Wild Mark]

and I bet Eric has thousands and perhaps we could crowd fund this project for Eric's mountain of desilvered prisms (if he still has them)

[LesDMess]

I currently have over a hundred vintage SLRs of various brands from late 50's to 80's - and have probably traded away another 50 or so, and I have not seen one obvious prism desilvering. I wonder what the root cause is?