[Michael Piziak]

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My love for macro photography started with the SMC Pentax-M 100mm F4 Macro. I picked up a copy of it for $20 because the owner said it had either lens separation, haze, or fungus. I posted some pics of it here in the forums, and members agreed it looked like lens separation - some thought haze. It had a classic looking "swirl" in the front lens elements when a flashlight was applied through it. But shucks, for $20, I bought it. The lens actually performed flawlessly, to me - took very sharp pictures & I made some excellent macro photos with it (well I thought so being my own judge, smiles).


A year or so after, I decided to treat myself and get a good copy of the lens. I disclosed the flaws of my copy and sold it on eBay - someone here in the forums bought it to practice cleaning it up. I actually doubled my money on it - one of the only times I've actually made money on a lens (smile).


To make a long story short, I went through two more copies of the lens (I still have the 3rd copy). Living in a rural area in West Virginia, of course I had to buy one from the auction site. The pics of it looked very good. I didn't ask the seller to shine a light through it, I just bought it - around $100 to $140 as I recall. When it arrived, I did a quick look through and it looked very good. However, when I applied a light through it, it had that classic swirl look - either haze or lens separation. I was dismayed, but decided to give it one more go. Disclosed the "flaw" and sold it for a lost on the auction site.

The third copy, that I still have, this time I asked the seller to shine a light through it and report back to me. He couldn't find any flaws and even sent me more pics of the light being applied to it. The copy was actually from a first time owner - actually, it was his deceased fathers lens that his dad bought new. It looked great in all the photos - looked brand new on the outside too. Came with the original case and packaging and everything. Well, again, upon it's arrival, I did the light test, and to my dismay it had the haze (or separation) too. As some are you are also, I'm a little OCD on the condition of my lens, but even I know when to cut my losses and learn to live with things. I decided it was just a gamble with this particular lens - the term crap shoot comes to mind. Regardless though, every copy that has the haze/separation performs fairly flawlessly. One person, here in the forums, that has bought and sold a lot of lens, told me that every copy that has ever passed through his hands has had the flaw(s).

I'm not sure exactly what happened during the manufacturing of this particular lens, but the haze/separation issue is a pretty high manufacturing "defect" in my opinion. All the other M class lens, I've been told, don't have this issue. Not even it's little macro brother, the SMC Pentax-M 50mm F4 Macro. If I ever decided to buy a copy again, which I won't, I'd buy from a Japanese seller. I've had remarkable accurate success with their descriptions of the lens they sell. And upon a search of this M 100mm macro from Japanese sellers on the stie, there remains a remarkably high percentage of copies that are reported as having haze or light haze.

Well, this post wouldn't be complete, to me anyways, without some photos.


Here is an actual copy that is for sale on the site now (it's at SMC PENTAX 100mm 1:4 Macro Lens K Mount With Caps Pentax-M | eBay)


From that one for sale, here are 2 photos of the lens, without a light applied through it, which is what you get a lot of when you are in the market for the lens:





&





But this seller actually included this photo with more light to the lens, and this is what you then see





And now to my 3rd copy of my lens, which I plan to keep forever





&





But when I shine a flashlight through it - actually makes it look a lot worse than what it is in reality (I think), but it is what it is.
Some of this is residue, left behind, from the Zeiss lens wipes I use, that is left behind.





But when it produces images like this, what is to complain about (?):










Your thoughts/comments please on the mystery of this hazy SMC




Regards,




Michael

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Last edited by Michael Piziak; 03-07-2022 at 09:03 AM.

[Lord Lucan]

Mine has some dusty looking stuff inside which I had attributed to dust or slight fungus, but not the swirl. It seems to give some milkiness to my pictures. I have tried to dismantle it but I cannot shift one of the five crosshead screws in the mounting ring. I cannot see how to get into it from the front.

I'm confused when you say :

Not even it's little macro brother, the SMC Pentax-M 100mm F4 Macro

Is that a typo for the 50mm macro? I thought you were talking about the 100mm F4 from the start.

That one you linked for sale on Ebay is in much poorer condition than mine. Mine is mint apart from the optical haziness. $180 is seriously over-priced.

[pschlute]

The M series 100 Macro is known for this. I have always assumed it is balsam separation, and there are two pairs of cemented elements in the 100mm Macro

[UncleVanya]

Is that a typo for the 50mm macro? I thought you were talking about the 100mm F4 from the start.

I had the same question.

[Bob 256]

As a last step in cleaning, try breathing on the lens to get some condensation and wipe that off with a clean lens tissue. If the smear pattern changes, you're doing some good and you might be able to clean up the smear with further wiping (always using a clean lens tissue because the old one will pick up the material causing the smear and just spread it around). But, as you noted, the smearing won't cause significant image issues unless you're shooting directly into some light source where the smear may reduce image contrast slightly.

[Michael Piziak]

Mine has some dusty looking stuff inside which I had attributed to dust or slight fungus, but not the swirl. It seems to give some milkiness to my pictures. I have tried to dismantle it but I cannot shift one of the five crosshead screws in the mounting ring. I cannot see how to get into it from the front.

I'm confused when you say :

Is that a typo for the 50mm macro? I thought you were talking about the 100mm F4 from the start.

That one you linked for sale on Ebay is in much poorer condition than mine. Mine is mint apart from the optical haziness. $180 is seriously over-priced.

Yes, that's a typo - I meant 50mm. I'll try to edit and correct that in the post. Thanks.

---------- Post added 03-07-22 at 09:27 AM ----------

I had the same question.

Yep, I meant 50mm. I corrected it in the original post.

Thanks!

---------- Post added 03-07-22 at 09:33 AM ----------

Mine has some dusty looking stuff inside which I had attributed to dust or slight fungus, but not the swirl. It seems to give some milkiness to my pictures. I have tried to dismantle it but I cannot shift one of the five crosshead screws in the mounting ring. I cannot see how to get into it from the front.

That one you linked for sale on Ebay is in much poorer condition than mine. Mine is mint apart from the optical haziness. $180 is seriously over-priced.

Yep, for one that obviously has the haze or separation, $180 is steep. but the ones in Japan that have no problem at all listed, can go $180 and up..... I guess we pay a premium for this lends in mint or near mint condition due to it having what seems to be a common manufacturing flaw at high percentage - just my 2 cents....

---------- Post added 03-07-22 at 09:35 AM ----------

The M series 100 Macro is known for this. I have always assumed it is balsam separation, and there are two pairs of cemented elements in the 100mm Macro

Yep. I've read that separation can occur when a lens gets too hot too. Like when left inside a vehicle on a sunny hot day.

My theory is that the glue, or batch of glue, used on the assembly line for this particular lens, was not up to spec....

---------- Post added 03-07-22 at 09:37 AM ----------

As a last step in cleaning, try breathing on the lens to get some condensation and wipe that off with a clean lens tissue. If the smear pattern changes, you're doing some good and you might be able to clean up the smear with further wiping (always using a clean lens tissue because the old one will pick up the material causing the smear and just spread it around). But, as you noted, the smearing won't cause significant image issues unless you're shooting directly into some light source where the smear may reduce image contrast slightly.

Thanks for the tips. I may use the Zeiss lens wipe, then follow it up with a dry micro fibre cloth....

[janosh]

My Pentax 28/2/8 A lens focuses so precisely by my K-70 that smudges from finger-touching appear clearly in files...I never did use "clear" filters when I shot film.... I eliminated the problem by removing the almost-clean 1A filter that was included with the used lens.

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Last edited by janosh; 03-07-2022 at 10:02 AM. Reason: oops

[pschlute]

My theory is that the glue, or batch of glue, used on the assembly line for this particular lens, was not up to spec....

Balsam separation is a relatively common issue with some lenses of this age, depending on the glued couplets.. Time takes its toll. I have seen it with other lenses. It is more of a general tech issue, than a "bad batch".

I am pretty sure the designers were not charged with the instruction to make a product that would last 45 years

[UncleVanya]

My Pentax 28/2/8 A lens focuses so precisely by my K-70 that smudges from finger-touching appear clearly in files...I never did use "clear" filters when I shot film.... I eliminated the problem by removing the almost-clean 1A filter that was included with the used lens.

I'd like to see this???? My experience has been that that I can put a 1/4x1/4 inch lens tissue fragment on the front element of most lenses and it will disappear into the noise and barely be noticeable even with side by side viewing. Rear element - that's another story.

[JoelA]

All,

I happen to have the M-Series 100mm f/4 Macro on the camera right now, so here's another data point (for what it is worth) :-)

Lens #6473284. Purchased used here on the forum. A heavily used copy. Definite dust and dirt in the lens (doesn't seem to impact picture quality).

Light "test":

1) Looking from the front of the lens "in" no haze to the naked eye holding the lens up to a bright blue sky
2) Looking from the back of the lens "out" no haze to the naked eye holding the lens up to a bright blue sky
3) Shining a very bright light (I-phone flashlight on full power) "in" no haze seen.
4) Shining a very bright light (I- phone flashlight on full power) "out" - thin haze is seen. Nothing circular. Not as "heavy" as the other photos shown.

I have no clue what to make of this!

The images from the lens are great and I'm (perhaps blissfully) unconcerned about light quality going "out" as the light for images is only coming "in".

Perplexed in Florida!

Joel

[Michael Piziak]

All,

I happen to have the M-Series 100mm f/4 Macro on the camera right now, so here's another data point (for what it is worth) :-)

Lens #6473284. Purchased used here on the forum. A heavily used copy. Definite dust and dirt in the lens (doesn't seem to impact picture quality).

Light "test":

1) Looking from the front of the lens "in" no haze to the naked eye holding the lens up to a bright blue sky
2) Looking from the back of the lens "out" no haze to the naked eye holding the lens up to a bright blue sky
3) Shining a very bright light (I-phone flashlight on full power) "in" no haze seen.
4) Shining a very bright light (I- phone flashlight on full power) "out" - thin haze is seen. Nothing circular. Not as "heavy" as the other photos shown.

I have no clue what to make of this!

The images from the lens are great and I'm (perhaps blissfully) unconcerned about light quality going "out" as the light for images is only coming "in".

Perplexed in Florida!

Joel

Well, of course every copy doesn't exhibit this. It's just that there seems to be a higher percentage than most all other M class lens.
It is a common enough thing that it can be said it is a common thing with this lens, I believe....

[gofour3]

I'm not sure exactly what happened during the manufacturing of this particular lens, but the haze/separation issue is a pretty high manufacturing "defect" in my opinion. All the other M class lens, I've been told, don't have this issue. Not even it's little macro brother, the SMC Pentax-M 50mm F4 Macro. If I ever decided to buy a copy again, which I won't, I'd buy from a Japanese seller. I've had remarkable accurate success with their descriptions of the lens they sell. And upon a search of this M 100mm macro from Japanese sellers on the stie, there remains a remarkably high percentage of copies that are reported as having haze or light haze.

Probably time to look at the K series 100/4 macro and just skip the M100/4 version?

Phil.

[GUB]

I'd like to see this???? My experience has been that that I can put a 1/4x1/4 inch lens tissue fragment on the front element of most lenses and it will disappear into the noise and barely be noticeable even with side by side viewing. Rear element - that's another story.

There is a key difference here - the tissue is close to opaque so stops light getting to the sensor. The fingerprint is translucent so most light passes through unfortunately in random directions - so hazing the image.

[UncleVanya]

There is a key difference here - the tissue is close to opaque so stops light getting to the sensor. The fingerprint is translucent so most light passes through unfortunately in random directions - so hazing the image.

Lens tissue when wetted is quite translucent. I don’t have any images right now. I’ll have to look. If you have any images I’d like to see them.

[GUB]

Lens tissue when wetted is quite translucent. I don’t have any images right now. I’ll have to look. If you have any images I’d like to see them.

I thought it was worth a quick experiment to see if I can simulate the difference. And yes this was set up to maximise effect.
Thought it was worth its own thread.
Finger print = Bad - PentaxForums.com