Carl Zeiss Jena Triotar 80/4 (M40x1): Long-focus uncoated (non-T) triplet lens

Another of my triplet lenses.

The Carl Zeiss Jena Triotar 1:4 f=8,5 cm (85mm, f/4).

This is the uncoated (non-T) version with an M40x1 mount. According to one source, this lens was manufactured in 1945.

The lens has 3 optical elements in 3 groups (yes, triplet). Though it is a long-focus lens, it is not a telephoto lens. That's why the body is so long for an 85mm lens, resembling earlier 135mm lenses.

It has 16 aperture blades. The aperture ring is clickless (f/4-f/32). 

The filter thread is 40.5mm.

The Triotar 85mm is surprisingly sharp for such an old triplet lens.

See also related notes:

• Carl Zeiss Jena Triotar 80/4: Samples [1] - FF - f/4 (2025-08-19)

Image albums:

• Carl Zeiss Jena Triotar 85/4

"Optek" light meter: User manual (in Russian)

This is an "Optek" ("ОПТЭК") light meter that was made in the USSR.

It is very compact and lightweight. In fact, it is even smaller than the Sekonic Auto-Leader L-188:

This light meter is optical, not electronic. It is a clone of a German model (FILUX Platin, Balda Expophot, or something similar).

Surprisingly, the light meter is quite accurate when the correct scale is chosen: there are three options depending on the lighting conditions to compensate for eye adaptation.

My copy was manufactured in either 1954 or 1955.

User manual (in Russian):

See also related notes:

• Sekonic Auto-Leader L-188 light meter (2024-09-26)

Image albums:

• Light meter

Kiyohara Soft VK70R 70/5: Samples [1] - FF - f/5

Camera: Sony a7c (FF, 24MP)

Lens: Kiyohara Soft VK70R 70/5 at f/5

A soft focus lens is a specific thing. It can be challenging to find the right scene for it.

Anyway, I prefer a 70mm focal length to an 85mm one.

See also related notes:

• Kiyohara Soft VK70R 70/5 (Nikon F): Rare soft focus lens (2025-07-19)

Image albums:

• Kiyohara Soft VK70R 70/5

Kenda Small Block Eight 27.5x2.1 tires

Kenda Small Block Eight 27.5x2.1 (52-584) K1047 tires, 60 TPI, folding bead. Very similar to my Kenda Small Block Eight 29x2.1 tires, but for smaller rims (584 vs 622).

These copies of the tire weigh 575g and 596g, without packaging.

See also related notes:

• Kenda Small Block Eight 29x2.1 tires (2024-06-23)

Image albums:

• Bicycle

NONS SL42 (II): Medium-format (P6) lenses - Biometar, Vega, Mir

First, I wanted to try my medium-format lenses on the NONS SL 42(II) - without the NFE, of course. These lenses have a Pentacon-6 (B) mount, so I found a Pentacon-6-Canon EF adapter.

The adapter is called the Pixco P60-EF and is relatively inexpensive. The flange focal distance is correct, but the Canon EF mount has a lot of play.

1. Carl Zeiss Jena Biometar MC 80/2.8

1/250 f/19:

1/250 f/16:

2. Vega-12B 90/2.8

1/250 f/22:

1/250 f/22:

3. Mir-26B 45/3.5

1/250 f/22:

1/125 (switched by mistake) f/16:

Results:

1. The small "throat size" of the leaf shutter leads to very significant vignetting. A lens must be very specific in order to work properly with this camera without NFE (NONS Format Extender). I don't know of any such lens. This is the reason why later NONS models (SL660 for Instax Square, SL645 for Instax Mini) have a built-in (non-removable) NFE.

2. Instax film has a rather small exposure latitude. Exposure parameters must be precise. Overexposure ruins colors and details. Underexposure makes a photo too dark to see.

3. As I mentioned earlier, Instax film has a native speed of ISO 800, which is rather high, and the fastest shutter speed is 1/250, which is rather slow. In sunny conditions, a very slow aperture (up to f/32) is necessary.

See also related notes:

• Mir-26B 45/3.5: Samples [1] - FF - f/3.5 (2025-09-13)
• NONS SL42 (II): NFE, Pentax K lenses (2025-08-25)

Image albums:

• Lens accessories
• Mir-26B 45/3.5
• NONS SL42 (II)

Pentax Q 03, 04, 05 lenses

My Pentax Q manual focus lenses:

Pentax Q 03 3.2/5.6 Fish-eye

Pentax Q 04 6.3/7.1 Toy Lens Wide

Pentax Q 05 18/8 Toy Lens Telephoto

These are all three of the Pentax Q manual focus lenses.

Also there was the Pentax Q 07 11.5/9 Mount Shield Lens, which is neither manual nor autofocus, it is a focus-free lens. I hope to obtain the Pentax Q 07 lens, but it is harder to find than the 03, 04, 05 lenses.

See also related notes:

• Pentax Q "Unique Lenses" (2025-09-19)

Image albums:

• Pentax Q 03 3.2/5.6 Fish-eye
• Pentax Q 04 6.3/7.1 Toy Lens Wide
• Pentax Q 05 18/8 Toy Lens Telephoto

Vega-12B 90/2.8: Samples [1] - FF - f/2.8

Camera: Sony a7c (FF, 24MP)

Lens: Vega-12B 90/2.8 at f/2.8

Since I have the Carl Zeiss Jena Biometar MC 80/2.8, I see no reason to use the Vega-12B.

See also related notes:

• Kiev-6S: Budget medium format film camera (2025-06-11)
• Carl Zeiss Jena Biometar MC 80/2.8 (P6): Medium format lens (2025-05-16)

Image albums:

• Vega-12B 90/2.8

Honda CL250/CL300 E-Clutch

It's interesting that the Honda CL250/CL300 motorcycles are now available with E-Clutch in certain markets.

(source)

(source)

As far as I know, the CMX 250/CMX 300 Rebels are also come with E-Clutch.

E-Clutch is better known on the Honda CBR650R and CB650R. It is an electronic clutch control mechanism that installed alongside the manual control. This allows riders to start moving and shift gears without using the clutch lever. However, it is not an automatic transmission, as the gears still need to be shifted manually. In any case, E-Clutch is a great help to beginners.

It is unclear if and when the Honda CL500 will be available with E-Clutch.

Image albums:

• Motorcycle

Viltrox AF 28/4.5: Firmware update (PC)

I was disappointed to find that I must use a mobile application that required registration to update the firmware of the Viltrox AF 28/4.5.

Fortunately, the USB-C connection can be used not only for powering the lens's Bluetooth, but also for updating the firmware with a PC. Some time ago, the Viltrox Lens application for Windows was released. More importantly, this application allows you to update the firmware without registering.

I updated the Viltrox AF 28/4.5 firmware to v1.08:

See also related notes:

• Viltrox AF 28/4.5: Firmware update (2025-02-19)
• Viltrox AF 28/4.5 (FE): Wide-angle pancake lens (2025-01-24)

Image albums:

• Viltrox AF 28/4.5 FE

Kiyohara Soft VK70R 70/5 (Nikon F): Rare soft focus lens

The Kiyohara Kogaku (KOPTIC) VK70R is a 70mm f/5 soft lens.

The optical design is 2 elements in 1 group. Overall, the lens is an homage to a Vest Pocket Kodak's lens (with the hood removed to make it faster and softer).

There is no distance scale on the focus ring, only a few unnumbered marks. The lens focuses beyond the infinity at the hard stop.

The 12-blade aperture is located in front of the optical group. The clickless aperture ring is located at the front end.

When a filter is mounted (to the 49mm thread), the aperture ring becomes inaccessible. Another oddity is that the aperture ring rotates beyond the marked f/5–f/11 range.

My copy has a Nikon F mount, but other mounts were available.

See also related notes:

• Kenko Soft 45/4.5: 45mm soft focus lens (2025-09-03)
• Kiyohara Soft VK70R 70/5: Samples [1] - FF - f/5 (2025-08-03)

Image albums:

• Kiyohara Soft VK70R 70/5

Pentax Q 05 18/8 Toy Lens Telephoto: Samples [1] - 1/2.3" - f/8

Camera: Pentax Q (1/2.3", 12MP)

Lens: Pentax Q 05 18/8 Toy Lens Telephoto (f/8 only)

The pincushion distortion is so slight that it is almost invisible. The image is noisy overall because the lens requires a lot of light.

See also related notes:

• Pentax Q 05 18/8 Toy Lens Telephoto (2025-07-05)

Image albums:

• Pentax Q 05 18/8 Toy Lens Telephoto

MVC

I developed an MVC framework a long time ago. At the time, the MVC (model-view-controller) pattern was considered modern.

The controller and view components could both work with data. But where was the strict border between them?

The solution was to separate the code according to the type of data access. The controller could manipulate all data. The view could only read data. This separation turned out to be simple and effective.

Kiev-6S: TTL light meter

The Kiev-6s can be used with a TTL prism viewfinder that has an uncoupled TTL light meter.

(The two indicators "the moon" and "the sun" light up together when the meter dial is in the right position)

The main problem is finding suitable batteries for it. It originally required a 3RTs53 mercury battery, which is unavailable today.

First, I used a power supply to test different voltages for the TTL light meter. I tried the 3.75-4.5V range. Surprisingly, the light meter was not very sensitive to the exact voltage. The difference was minimal and depended more on the accuracy of the dial rotation.

However, the light meter itself is inaccurate. It typically shows a much faster shutter speed, which results in an exposure that is up to three stops underexposed (-3EV). This does not depend on power voltage.

After the tests, I decided to continue using the waist-level viewfinder and a dedicated light meter. 

By the way, would using an older, non-TTL prism viewfinder make the image brighter than a TTL viewfinder?

See also related notes:

• Kiev-6S: Budget medium format film camera (2025-06-11)
• 3RTs53 battery (2025-04-13)
• Регулируемый импульсный блок питания Gophert CPS-3205 II (2018-04-12)

Image albums:

• Kiev-6S