Pentax Q: 365MP FF emulation

The Pentax Q has a tiny, 1/2.3" (6.17 x 4.55 mm) sensor. Even with 12MP, it features about 650 pixels per mm. That's a really high pixel density. If an FF sensor had the same density, it would be about 365MP.

But what about lens resolution power? Would an FF lens be able to "resolve" that many megapixels?

To find out, I did some testing with the Pentax Q (as a 365MP FF emulation) and the Pentax K-m (as a 24MP FF emulation). I took pictures with both cameras using the same Pentax K 28/3.5 lens (introduced in 1976) at f/5.6.

Then, I upscaled (with Lanczos) an image from the K-m by a factor of 3.9 (sqrt(365/24)) and compared crops from the two images: one from the Pentax Q (on the left) and upscaled one from the Pentax K-m (on the right).

Clearly, the Pentax Q (with its "365MP FF") provides much more detail than the Pentax K-m (with its "24MP FF"), even when using an old film-era lens.

See also related notes:

• Pentax Q: Useless mirrorless camera (2025-02-14)
• Pentax K-m: 10MP CCD DSLR (2023-12-23)
• Pentax K 28/3.5, K 30/2.8, K 35/3.5: опять к старой теме (2022-05-22)

Image albums:

• Pentax K 28/3.5

SunRace CN12A: 12-speed chain

I ordered a chain for a 12-speed drivetrain without knowing which chainring I would use. Because Shimano 12-speed chains are incompatible with some non-Shimano chainrings, I chose a 12-speed SunRace chain as a universal option.

SunRace CN12A, 126 links.

See also related notes:

• Shimano M7100-1 (SLX): Crankset 175mm, 32T (2025-11-11)
• Shimano RD-M8100-SGS (Deore XT): 12-speed rear derailleur (2025-10-17)

Image albums:

• Bicycle

TTArtisan 75/1.5: Samples [1] - FF - f/1.5

Camera: Sony a7c (FF, 24MP)

Lens: TTArtisan 75/1.5 at f/1.5

It seems the goal was to increase the resolution of the center of the image. However, the center is overcorrected, creating inconsistency with the borders and corners. I would also like to see some spherical aberration with this type of lens. And there is noticeable longitudinal chromatic aberration with fast apertures.

See also related notes:

• TTArtisan 75/1.5 (M42x1/45.5): Homage to Biotar 75/1.5 (2025-10-27)

Image albums:

• TTArtisan 75/1.5

Phone holders for tripod

Sometimes, I attach a mobile phone to a tripod. This is especially useful for recording videos. I have several phone holders for tripods.

The two metal ones on the right are the best. They are both convenient and reliable.

The second one from the left is made of plastic. I used it often before, but it broke.

Image albums:

• Tripod

Pentax Q7: Better, but still too specific

I have the Pentax Q mirrorless camera. I still think it's rather useless. However, to be objective, I bought another camera from the Q series.

It is the Pentax Q7.

(black Q and  silver/black Q7)

After using the Q7 for some time, I realized that it is better. There are a few reasons why.

1. It has a larger, 1/1.7" (12MP) sensor. Its crop factor is 4.6x instead of 5.6x.

2. The larger sensor provides better image quality and a wider angle of view. For example, the 02 Standard Zoom lens provides a ~24mm wide-angle equivalent, which is uncommon for an older compact camera.

3. The Pentax Q7 is noticeably faster than the Pentax Q. I find the speed of the Q very annoying.

4. Although the controls are almost identical, the Pentax Q7 is more convenient. For instance, the Q7's power switch button is much better and more responsive.

5. The quick dial on the Pentax Q is completely useless to me. In contrast, the quick dial on the Pentax Q7 has two useful functions: Focus Peaking and ND Filter.

So, if you want to have fun in struggling with a Pentax Q-series camera, at least buy the Pentax Q7.

See also related notes:

• Pentax Q: Useless mirrorless camera (2025-02-14)

Image albums:

• Pentax Q (series)

Shimano M7100-1 (SLX): Crankset 175mm, 32T

Switching from an 11-speed drivetrain to a 12-speed one meant replacing the 11-46 cassette with the 11-51 cassette. This changes the slowest gear ratio from 46/30=1.5333... to 51/30=1.7 when using the stock 30T chainring. This is too slow for my purposes. Therefore, I wanted to replace the chainring.

While the stock FSA Comet MegaTooth 30T chainring can be replaced, finding a replacement is difficult for me because of its rare FSA direct mount.

A solution I chose is to replace the crankset with the Shimano FC-M7100-1 (Hollowtech II, SLX), 175mm option.

The chainring is 32T (51/32=1.59375) because I am unsure if there is enough space for a 34T (51/34=1.5) near the right chainstay of the Cujo 1.

This also means that I can use Shimano's 12-speed chains, which have a different shape.

The crankset and 32T chainring together weigh 635g.

See also related notes:

• SunRace CN12A: 12-speed chain (2025-11-19)

Image albums:

• Bicycle

Rikenon 50/2: Samples [1] - FF - f/2

Camera: Sony a7c (FF, 24MP)

Lens: Rikenon 50/2 at f/2

From my experience, the Rikenon 50/2 and the XR Rikenon 50/2 have the same optical design.

See also related notes:

• XR Rikenon 50/2 vs Rikenon 50/2 (2025-03-27)
• Rikenon 50/2 (K): Cheaper version of XR Rikenon 50/2 (2025-03-23)
• XR Rikenon 50/2 (K): Interesting 50mm lens (2024-09-20)

Image albums:

• Rikenon 50/2

From Philips 200P7ES to Samsung 245B

My old Philips 200P7ES (20", 1600x1200) monitor broke again, for the fourth time (2011, 2017, 2020). 

Instead of fixing it this time, I replaced it with another old Samsung 245B monitor (24", 1920x1200). This monitor is one year older (from 2007), but has only been repaired once.

See also related notes:

• Поломка монитора Samsung 245B (не включается) (2020-09-27)
• Монитор и электролитические конденсаторы (3) (2020-08-29)
• Монитор и электролитические конденсаторы (2) (2017-09-02)
• Монитор и электролитические конденсаторы (1) (2011-09-20)
• Монитор Philips 200P7ES (20", 1600x1200) (2008-01-30)

Viltrox AF 28/4.5: v1.10 firmware

The v1.10 firmware is now available for the Viltrox 28/4.5 lens.

Once again, I updated it with the Viltrox Lens application for Windows.

See also related notes:

• Viltrox AF 28/4.5: Firmware update (PC) (2025-07-21)
• Viltrox AF 28/4.5 (FE): Wide-angle pancake lens (2025-01-24)

Image albums:

• Viltrox AF 28/4.5 FE

Shimano SL-M8100-R (Deore XT): 12-speed shifter

This is a next component for 12-speed drivetrain.

It is the Shimano SL-M8100-R (Deore XT) shifter (shift lever), in the clamp version.

It does not have a gear indicator window. Moreover, there is no such option for this shifter at all.

The shifter with an unshortened cable weighs 137 g.

See also related notes:

• Shimano RD-M8100-SGS (Deore XT): 12-speed rear derailleur (2025-10-17)

Image albums:

• Bicycle

Mir-26B 45/3.5: Samples [2] - 6x6 (expired Svema DS-4 film) - f/3.5

Once, I needed a 120 film take-up spool. The simplest solution was to get an expired roll of Svema color DS-4 (Свема ДС-4) film.

It should have been processed before June 1990.

I rewound the film onto a rod, then took the spool out to use it. After some time, I thought, "Why don't I shoot this expired film just for fun?"

So, I rewound the film onto the spool back and took some pictures with my Kiev-6S (6x6) camera and the Mir-26B 45/3.5 lens.

The film is ASA/ISO 50, but I exposed it as ISO 5-10. This required using an f/3.5 aperture for all shots.

This color negative film should be developed using the so called "Sovcolor" process. It is a Soviet derivative of the German Agfacolor process. However, I decided to develop the film using a B&W developer (this was my second attempt at developing color film as a B&W negative). I developed the film for 9 min with Pyrocat-HDC (1:1:100, 20°C) and fixed it with a neutral fixer (plain sodium thiosulfate solution). There was no bleaching step.

The negatives turned out too dark, but I successfully digitized them.

Although there are some spots and streaks, the result is surprisingly usable. Note that there are no backing paper numbers shown on the negatives (a common issue with expired 120 film).

See also related notes:

• NONS SL42 (II): Medium-format (P6) lenses - Biometar, Vega, Mir (2025-07-29)
• Kiev-6S: Budget medium format film camera (2025-06-11)
• Developing a color C-41 film as a B&W negative (2024-11-23)

Image albums:

• Photographic film
• Mir-26B 45/3.5