What to do with a 25mm, f/9.5 Triplet (from Instamatic 20)

jay moussy · Apr 18, 2020

I took apart a beat up Instamatic 20 (candy bar shape, 110), hoping to find a workable mini-shutter for a pinhole project (I did!)

In the process, I had access to the lens, and it extracted easily.
Looking up the Instamatic 20 specs, it turns out the lens is a 25mm, f/9.5 Triplet.

What low-fi wonder could I create with this lens?

BTW, the Instamatic innards were a bit more complex than anticipated. Interesting build. quite a few lever, springs.

BobD · Apr 18, 2020

Find another and make a stereo spy camera.

jay moussy · Apr 18, 2020

BobD said:
Find another and make a stereo spy camera.

I have a couple of ViewMaster viewers....

I could update the "National Parks" series, and the "French Riviera". Road trip!

Donald Qualls · Apr 18, 2020

That's actually not far from the specs of the original Viewmaster camera's lenses. It's probably not a coincidence that a 110 frame (based on several older 16 mm still camera frames) is only a little bigger than a Viewmaster frame. The Viewmaster camera used a little optical trickery to put two of those frames in opposite corners of a single 35 mm frame, despite the two lenses being approximately two inches apart (close to ocular separation) and level with the camera body.

That said, you could easily fit *two* Minolta 16 (or Kiev 30) film chambers, advance systems, and gates behind a pair of lenses 67 mm apart, and shoot 13x17 mm stereo on two films at once. Of course, if you're doing that, you'll have a pair of focusing triplets, f/3.5 at around 28 mm, and won't really need the Kodak lens you have -- though you could possibly use it for a reflex viewfinder...

Bill Burk · Apr 18, 2020

Donald Qualls said:
That's actually not far from the specs of the original Viewmaster camera's lenses. It's probably not a coincidence that a 110 frame (based on several older 16 mm still camera frames) is only a little bigger than a Viewmaster frame. The Viewmaster camera used a little optical trickery to put two of those frames in opposite corners of a single 35 mm frame, despite the two lenses being approximately two inches apart (close to ocular separation) and level with the camera body.

That said, you could easily fit *two* Minolta 16 (or Kiev 30) film chambers, advance systems, and gates behind a pair of lenses 67 mm apart, and shoot 13x17 mm stereo on two films at once. Of course, if you're doing that, you'll have a pair of focusing triplets, f/3.5 at around 28 mm, and won't really need the Kodak lens you have -- though you could possibly use it for a reflex viewfinder...

Didn’t they just put the pairs on completely different frames about 2 inches apart?

Bill Burk · Apr 18, 2020

The Instamatic 20 is my favorite all-mechanical two-speed shutter... The only one of the original series that doesn’t need a battery.

Donald Qualls · Apr 18, 2020

Bill Burk said:
Didn’t they just put the pairs on completely different frames about 2 inches apart?

Most 35 mm stereo cameras did this -- your first frame went on frame 1 and 3 (which, if full frame, have centers around 75 mm apart, so close to 3 inches, slightly hyperstereo), second on 2 and 4, then the winding mechanism would advance three to shoot on 5 and 7, etc. I now see Viewmaster cameras were even odder than I'd recalled. They used a full frame (8 sprockets) advance, but exposed a bit less than a quarter frame (looks like about 10x10 mm, maybe a mm larger each way) on the bottom half of the film, leaving two unrelated images between the pair, and a blank space associated with each image, for handling the cut frame for mounting -- and then shifted the lenses and frame masks and did the same on the top half of the film while winding the film back into the cassette. This apparently produced 69 stereo pairs on a 36 exposure roll of slide film -- which would make several stereo image wheels (10 pairs per wheel, or something like that?). Good economical use of expensive film and processing -- you'd just request uncut film back instead of slide mounting, and Sawyers sold a cutter and mounting tools and materials.

Patrick Robert James · Apr 18, 2020

It would be kind of hard to make a camera around the lens unless you did something with a digital camera. If you do darkroom work try putting it on your enlarger. You'd have to get it pretty close to the film but I'd bet it would give you an interesting circular image with a 35mm neg. It might even cover if you do really small prints.

You could try inverting it and using it as a super duper macro lens. That would be pretty simple to do.

Might make a decent loupe too.

Just curious. You didn't say if the shutter idea worked out....

jay moussy · Apr 19, 2020

In retrospect, I am sorry I tore the camera apart, even though this was left for dead at my town's reuse-and-recycle shack, and I have no way to use this format - EDIT: I forgot the Minolta 430E, (can work without battery except for flash, I think).

Patrick Robert James said:
....hard to make a camera around the lens unless you did something with a digital camera. If you do darkroom work try putting it on your enlarger.
You could try inverting it and using it as a super duper macro lens. That would be pretty simple to do.
Might make a decent loupe too.
Just curious. You didn't say if the shutter idea worked out....

Yes, just handling the lens, all the above seem to have some potential.

The shutter is a 6 mm round metal piece, spring-loaded, as there was a actuator bar pointing at it.
It is attached to a angled sheet metal piece that I can cut down. It can become a pinhole shutter to a lens-less Kodak Tourist that I got from a forum member (thank you Rick!)
The Tourist could be a f260 pinhole, and using 100-400 ISO film range, points to 15 to 70 second exposures. It is unclear if I will retain the shutter spring and glue on a cable release post to push open, or just glue on a small manual lever.

blockend · Apr 29, 2020

Viewmaster sold two cameras IIRC, a base model and one with superior optics. What mesmerized me as a child was the hyperreal quality of the colour. I don't know if the company marketed a film for those cameras, presumably the commercial discs used an interneg like movie production. I still have my viewer and discs in a Viewmaster box, and even had a projector for one Christmas.

Not sure what you'll do with a tiny 3-element lens, triplets have their own unique style.

Donald Qualls · Apr 29, 2020

Seemingly, the expectation was that consumers would use Ektachrome or Kodachrome (the latter in the early days, as Ektachrome was a much later development) in the genuine Sawyer's cameras. I agree, the mass produced reels were almost certainly printed with a process much like making a motion picture positive from a camera negative -- after all, they sold literally millions of those reels (I don't think I knew anyone who didn't have a viewer and a few reels when I was a kid in the 1960s).

What to do with a 25mm, f/9.5 Triplet (from Instamatic 20)

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