Pentax auto 110 lens thread

[L0n3Gr3yW0lf]

Please, no need to apologise!! I'm totally satisfied with the knowledge that no one can substantiate the plastic optical elements. This is having a great soothing effect on my psyche, as is.

About the hood issue; you're totally right! Unfortunately, the original Pentax hoods made out of rubber have mostly desintegrated by now, as rubber hoods do. I, myself, dare not use my original hoods, as they will probably break upon unfolding. They stay in my red box.

But, to have a hood is good!

As I only use my Pentax-110 lenses in anger on my M4/3 and Pentax Q cameras, it's a little bit easier for me, and supposedly for you too, as the lens equivalency doesn't mandate hoods in the original "wideness". Instead it's possible to find good looking replacement hoods that won't vignette.

For my 24 mm (48 mm eq on M4/3) I simply use one of these:
View attachment 823033
and for both the 18 mm (36 mm eq) and 50 mm (100 mm eq) it's possible to get nice metal hoods in both wide Ø30.5 mm, and tele Ø37.5 mm varietys in China.

And the Ø49 mm lenses are no problems finding hoods for. Also I don't have any of these lenses I've got hoods, though.

It's another story if/when you want to use them on APS-C sensor size cameras.

Best regards/Erik

Footnote:
Pentax Auto 110 lenses

Pentax-110 18 mm F2.8 Wide-angle lens, 6 elements in 6 groups, filter Ø30.5 mm
Pentax-110 24 mm F2.8 Standard lens of 6 elements in 5 groups, filter Ø25.5 mm
Pentax-110 50 mm F2.8 Telephoto lens of 5 elements in 5 groups, filter Ø37.5 mm
Pentax-110 70 mm F2.8 Telephoto lens of 6 elements in 5 groups, filter Ø49 mm
Pentax-110 20mm—40 mm F2.8 Zoom lens of 8 separate elements, filter Ø49 mm

I agree, such delicate manufacturing was probably not thought to last almost 50 years. Less not think about lasting another 50 years in my own hands.
I would like to go with metal hoods but not know the exact limitations of vignetting and angle of view with 2x crop factor I would not take upon myself to experiment with buying to many things off evilBay and wait for delivery from China (I might end up opening my own metal scrapyard in the end of such an experiment ).
Any volunteering of such information would greatly be appreciated, if not to form a base of what works on what to save up people’s time and money but at least get the best that we can from these little gems. (In the end it’s only us, the community, who would really care about this lenses as they will eventually pass into fading of memory and history.

 

[Erich_H]

I agree, such delicate manufacturing was probably not thought to last almost 50 years. Less not think about lasting another 50 years in my own hands.
I would like to go with metal hoods but not know the exact limitations of vignetting and angle of view with 2x crop factor I would not take upon myself to experiment with buying to many things off evilBay and wait for delivery from China (I might end up opening my own metal scrapyard in the end of such an experiment ).
Any volunteering of such information would greatly be appreciated, if not to form a base of what works on what to save up people’s time and money but at least get the best that we can from these little gems. (In the end it’s only us, the community, who would really care about this lenses as they will eventually pass into fading of memory and history.

Scrap yard owner. Sounds like a possible career track, doesn't it?

About the 24 mm hood; (C to CS adapter) it doesn't vignette, as long as you don't put one or two more as extension tubes between lens and camera. And then, the vignetting probably originates from the extension tubes, anyway.

You'll find examples of use of extension tubes earlier in this thread.

And with only one, as a hood, all my posts using the 24 mm in this thread is with this type hood. Which is easy to find. And cheap.

I'll see what I can do about links to the others.

 

[barry13]

Footnote 2:
Pentax Auto 110 lenses

Pentax-110 f:2.8/18 mm wide-angle lens
(6 elements in 6 groups) filter Ø30.5 mm
Pentax-110 f:2.8/24 mm standard lens
(6 elements in 5 groups) filter Ø25.5 mm
Pentax-110 f:2.8/50 mm telephoto lens
(5 elements in 5 groups) filter Ø37.5 mm
Pentax-110 f:2.8/70 mm telephoto lens
(6 elements in 5 groups) filter Ø49 mm
Pentax-110 f:2.8/20 - 40 mm zoom lens
(8 elements in 8 groups) filter Ø49 mm

Hi, thanks for this list... there was also a fixed-focus / hyperfocal 18mm lens. I haven't come across one in person, nor the zoom, and don't know the filter size.
https://en.wikipedia.org/wiki/Pentax_Auto_110#Lenses

Re glass v plastic: My mom dropped her 70mm lens from her Auto 110, and it broke. My father later got her an Auto 110 Super kit with another 70mm.
Also, the 70mm is heavy enough that I don't see how it could be plastic, as are the 50mm and 18mm.
Only the 24mm is so light (and tiny) that it's harder to judge.

BTW, the body on the 70mm seems to be mostly metal.

 

[Erich_H]

... including today, scouring the internet for the information you requested instead of flying off to Dreamland.
http://www.submin.com/110/collection/pentax110/
This is the most comprehensive information source I could find ...

110 - Variations in Pentax Subminiature Cameras

Quote:
The least common Auto 110 variant is the "Black Asahi Panhead".

There aren't many of these around.

The very first cameras produced had the name "ASAHI", located on the penta-prism front, filled in white epoxy/enamel just the same as the names "AUTO 110" and "PENTAX".

Sometime early on this was left unfilled (Black) for the remainder of production.

All Auto 110s have two small panhead machine screws on their backside - one on each side of the viewfinder.

During the 1st year or so these screws had a slotted head.

The change from pan head to Phillips screws (took place) somewhere in the range {1157431, ..., 1308039}.
Unquote

Thanks to you and this link, I now know that I have the Black Asahi Panhead variant of Pentax auto 110.

And it feels so good! Suddenly, it's like my life is so much more meaningful!

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My Black Asahi Panhead is serial number # 1181537.

I've never even thought about this before.

Even the manuals have pictures of the Black or White variants on the cover!

There it is. A new fact for the nerds, errh, that is, specialists!

Thanks/Erik

 

[L0n3Gr3yW0lf]

You are very welcome ... the more you know the more you can forget in later years

 

[RichDesmond]

...During the 1st year or so these screws had a slotted head.

The change from pan head to Phillips screws (took place) somewhere in the range...

There it is. A new fact for the nerds, errh, that is, specialists!

Thanks/Erik

Speaking of nerds, especially the utterly pedantic type, those “Phillips” screws aren’t Phillips, but a different type of cross-head known as JIS. (For “Japanese Industrial Standard”)
Phillips screwdrivers don’t fit very well and make stripping the head very easy. If you work on Japanese products, a set of JIS screwdrivers is worth its weight in gold.

And there you have, “the rest of the story”.

 

[Erich_H]

Speaking of nerds, especially the utterly pedantic type, those “Phillips” screws aren’t Phillips, but a different type of cross-head known as JIS. (For “Japanese Industrial Standard”)
Phillips screwdrivers don’t fit very well and make stripping the head very easy. If you work on Japanese products, a set of JIS screwdrivers is worth its weight in gold.

And there you have, “the rest of the story”.

There you are! Another reason to be happy about owning the Black Asahi Panhead!

My screwdrivers fit. At least they fit those two screws flanking the viewfinder. The rest of the screws are, of course, of the other, nerdy type!

But never mind that. My life nevertheless feels substantially more blessed now, than it did before I knew that I was the happy owner of the genuine, rare Black Asahi Panhead!

I feel for the poor people that only owns the White Asahi Panhead, or the even less collectible, common garden variety Black Asahi! But not everyone can be blessed.

Nor can everyone win the lottery!

QUOTE
Pentax stopped painting in the "ASAHI" on the Auto 110 before the end of the first year of production.

Shortly after that they also changed the pan head screws to Phillips heads. So these must be the rarest of the Auto 110 cameras.

This, however, does not seem to be reflected in the auction price as few sellers include serial numbers or this level of detail in the auction.
(Comment: This must change!)

10306xx has been reported as white ASAHI. 1059xxx and 1218xxx has been reported as being a Black Asahi Panhead and 1260xxx as a Phillips, giving the range:

(White Asahi Panhead, up till) >>>
after 10306xx and before 1059xxx

to

after 1218xxx. and before 1260xxx >>> (after, until end of production, Black Asahi)

There may have been an overlap in production, using whatever screws were available.
UNQUOTE

Quoted from:
http://www.submin.com/110/collection/pentax110/

EDIT1: About specialist knowledge, the guy with the website quoted above, leaves me eating his proverbial dust. And don't dare call it nerdiness! It's called specialist knowledge!

EDIT2: I've replaced the [xxx] in the numbers from the quote above with [000] for the calculation that follows!

My Black Asahi Panhead is serial number # 1181537, one of (1.260.000 − 1.030.600 = worst case) 229.400 pieces, or (1.260.000 − 1058999 = best case) 201.001 pieces.

EDIT3: @ex machina has reported his Black Asahi Panhead as serial number # 1064870! Allow me to congratulate my fellow lottery winner!

I'm prepared to listen to your offers.

Not that I want to sell, I just want you to eat your hearts out! This being said in the most benevolent spirit of utmost humility, of course.

Footnote: Someone really oughtta tell the guy with the website www.submin.com that his Phillips screws are in reality JIS screws. This error kind of puts a blemish on the whole, grander picture!

 

[Shadetree]

Some more Pentax 24 mm with my 20MP IMX269, XiaoYi YI M1 (Chinese M4/3 camera).

View attachment 802460

https://www.aliexpress.com/item/32815460937.html?

These b/w pics are shot with a 5 mm extension ring (the lens hood). Aperture disc inserted. Uncropped.

View attachment 802450

View attachment 802451

View attachment 802457

View attachment 802452

This is shot without extension tube, lens hood back in place, wide open, and uncropped. The aperture disc fell out when I unmounted the extension tube. Have to find some black plastic.

View attachment 802453

Lastly, a center crop of Lady Mismet de Tortoise, on guard duty. With aperture disc.

View attachment 802456

JPEG conversion in camera.
I used the app to get the pictures on to the phone, and the app doesn't transfer RAW.

All things considered, not too shabby, IMHO.

Thanks/Erik

How do you make your aperture discs?

 

[Erich_H]

How do you make your aperture discs?

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Using plastic for aperture discs. The plastic used is cut from video cassette cases or SIM cards. You get the idea.

The round holes are made with a ring binder hole puncher. Gives me approximately an f:4.5 to f:5.6 stop.

I'm using a quarter dollar (US) as a template to cut the plastic discs.

After some sanding down they fit perfectly, and is easily removable by unmounting lens and C-CS adapter and just pushing the disc out.

EDIT: main part of the text and the picture reposted from an earlier post in this thread.

 

[Mike Wingate]

Bad news. I have found the Pentax 110 kit. Camera. Motor drive. Flash gun. Filters. 18, 24, 70mm lenses and 2 X converter. Now dithering what to do about mounts. DIY C-mount or £20 Roksan from eBay.

 

[Mike Wingate]

Not filters, but close up lenses. I have read this 7 page missive. Thinking of using the 70mm lens instead of buying the O75mm. Does anyone use the 2 X converter?

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[Erich_H]

Not filters, but close up lenses. I have read this 7 page missive. Thinking of using the 70mm lens instead of buying the O75mm. Does anyone use the 2 X converter?View attachment 860478

No. But I'd buy it from you, if you'd sell it!

 

[Erich_H]

Bad news. I have found the Pentax 110 kit. Camera. Motor drive. Flash gun. Filters. 18, 24, 70mm lenses and 2 X converter. Now dithering what to do about mounts. DIY C-mount or £20 Roksan from eBay.

One thing to keep in mind: as the DIY adaptation is more of a fixed conversion to C-mount, by glueing the first, filed down, C to CS adapter to the lens, than a switchable adapter, it's more of a one-per-lens kind of thing.

For me it's no big deal, as I've got three sets of 18/24/50 mm lenses.

 

[barry13]

Hi, the Roxsen adapter looks the same as the Fotasy I have. It's very wobbly with the 'larger' lenses, especially the 70mm, and causes tilt effects.

The Kipon adapter is much better.

 

[Mike Wingate]

Some good advice. I just wonder how much use they will get?

 

[kmcsmart]

One thing to keep in mind: as the DIY adaptation is more of a fixed conversion to C-mount, by glueing the first, filed down, C to CS adapter to the lens, than a switchable adapter, it's more of a one-per-lens kind of thing.

For me it's no big deal, as I've got three sets of 18/24/50 mm lenses.

@Erich_H,
I love your C-CS adapter solution for the Pentax 110 lenses.

I have 3 lens that I just bought but haven't received yet. They are the 18,24, and 50mm. I would like to make an adapter. I already have a CCVT lens so it seems like a good option for me.

Here's my question. Why do you glue the first C-CS mount to the lens? Can I not leave that unglued so the lens can go back on the original camera? Do I need to sand down a specific ring for each of the lens to accommodate the focus to infinity?

I am assuming I need to buy:
1 - C mount to MFT adapter (attaches to the camera)
1 - C to CS adapter (that gets mounted to the MFT adapter)
3 - C to CS adapters (each to be sanded down for their specific lens for focus to infinity)
1 - C to CS adapter to be used as a lens hood on my 24mm lens (or inserted behind the lens to be used for magnification)

I guess a small drop of LOCTITE Purple might be a good way to put the sanded down adapter on the camera lens.
https://www.henkel-adhesives.com/ca/en/insights/all-insights/blog/about-purple-threadlocker.html

Karen

 

[Erich_H]

@Erich_H,
I love your C-CS adapter solution for the Pentax 110 lenses.

I have 3 lens that I just bought but haven't received yet. They are the 18,24, and 50mm. I would like to make an adapter. I already have a CCVT lens so it seems like a good option for me.

Here's my question. Why do you glue the first C-CS mount to the lens? Can I not leave that unglued so the lens can go back on the original camera? Do I need to sand down a specific ring for each of the lens to accommodate the focus to infinity?

I am assuming I need to buy:
1 - C mount to MFT adapter (attaches to the camera)
1 - C to CS adapter (that gets mounted to the MFT adapter)
3 - C to CS adapters (each to be sanded down for their specific lens for focus to infinity)
1 - C to CS adapter to be used as a lens hood on my 24mm lens (or inserted behind the lens to be used for magnification)

I guess a small drop of LOCTITE Purple might be a good way to put the sanded down adapter on the camera lens.
https://www.henkel-adhesives.com/ca/en/insights/all-insights/blog/about-purple-threadlocker.html

Karen

The glue is the easiest way to get the sanded down part to attach to the lens. The 110 bayonet is of a smaller diameter than the opening in the C/CS CCTV mount.

I put one sanded down C/CS on each lens. This is because I have three sets of 110 lenses. But I'm using "office glue" like Casco RX, or the like, so I can get the lens back to original state if I want. The Loctite looks to be like that.

And the Pentax-110 lenses have the same amount of filing/sanding down that needs to be done to the adapter. That's why I had to glue a cardboard distancer on my first lens. I took off a little too much. But number two and three are easier. File down the most, then adjust by sanding. I actually didn't sand. I just filed. Quicker.

So for a three lens set conversion you'll need three filed down pieces and three original ones plus three C to M4/3 adapters if you go the one-per-lens route.

I'm usually buying the C/CS adapters in a ten-pack. Cheaper. You can get black or silver coloured ones. Like the C to M4/3 adapters. Kind of crazy cheap...

I've got some Fujian C-mounts (25/35/50 mm) in both black and silver finish. On my E-PM1 the silver ones look best. They are so cheap, that buying more of them (from China), and getting the seller to put a ridiculously low Customs value on the package (like around one tenth of actual sales price) can offset the cost of an extra lens.

So it actually is cheaper to buy more to be sent in a single parcel, when you factor in Customs duties and fees.

Which is per parcel. Where I live, the oppressor regime charge an approximate US 10 (under US 25 value of goods) to US 20 fee per parcel on top of the actual Customs duties and VAT. Like US 10 in fee for US 1 in taxes...

And where I live, the regime is of the nosier sort. I can't imagine Canada being much worse. Or better. And with so many parcels coming in from China, and the average customs employees knowledge of what things cost in China, I'd think it's pretty risk free...

 

[kmcsmart]

The glue is the easiest way to get the sanded down part to attach to the lens. The 110 bayonet is of a smaller diameter than the opening in the C/CS CCTV mount.

I put one sanded down C/CS on each lens. This is because I have three sets of 110 lenses. But I'm using "office glue" like Casco RX, or the like, so I can get the lens back to original state if I want. The Loctite looks to be like that.

And the Pentax-110 lenses have the same amount of filing/sanding down that needs to be done to the adapter. That's why I had to glue a cardboard distancer on my first lens. I took off a little too much. But number two and three are easier. File down the most, then adjust by sanding. I actually didn't sand. I just filed. Quicker.

Thanks. I understand now. You are filing off some of the threads on the adapter to make the diameter of the adapter friction fit to the 110 bayonet. That makes sense. Well done.
Thanks again.
Karen

 

[Erich_H]

Thanks. I understand now. You are filing off some of the threads on the adapter to make the diameter of the adapter friction fit to the 110 bayonet. That makes sense. Well done.
Thanks again.
Karen

Now I don't get it.
The bayonet part of the 110 lens is smaller than the opening of the C/CS adapter.
No friction around. That is where the glue comes into play.

I'm filing down the internally threaded end of one of the C/CS adapters to get the same focal flange as a proper C-mount lens (17.526 mm) on the Pentax-110 lens in combination with the unmodified C/CS adapter. I'm not filing down the externally threaded end. (The end you'll screw into the C to M4/3 adapter)

Then you'll have infinity focus when mounted in a C to M4/3 adapter. Or indeed in any camera with C-mount adapters available. I'm using my lenses in a Pentax Q, for instance.

List of focal flange distance

In this list a way down the page you'll see, for instance, that my Q has a 9.2 mm ffd, while M4/3 cameras have 19.25 mm ffd. Also my favourite, the PK/M42 mount, which has 45.46 mm ffd.

In short, the shorter the ffd of the camera, the most stuff can be adapted.

On my Q, I can put almost everything.
On M4/3 you can't put a Q-lens, but you can adapt a PK or M42 lens to it.

This is speaking about infinity focus capable adapter types with no optical elements inside, eg, just an empty tube.

I'm sorry if this is unclear. I'm not sure I understand it myself. But for me it's getting very late (GMT+1). And I know it's working.

Try this post! (If you have not read it already)

Tell me if you need more information or photos!

Best of luck!

 

[Mike Wingate]

Hi, the Roxsen adapter looks the same as the Fotasy I have. It's very wobbly with the 'larger' lenses, especially the 70mm, and causes tilt effects.

The Kipon adapter is much better.

No wobble detected on the mount/body with the P70mm, filter and rubber lens hood mounted.