Angarsk: 8 photo card set from 1974 (and 2023)

Angarsk photos from 1974: 8 cards and 2 covers. I added my 7 photos of the same places taken in early spring 2023 (no leaves on the trees yet for better visibility).

Cover-1: Ангарск. Первые высотные (Angarsk. The first high-rises)

Cover-2: Дворец пионеров (A young pioneer palace)

1. Проспект К.Маркса (Karl Marx Prospect)

2. Политехнический институт (Polytechnic Institute)

3. Спортивный дворец (A palace of sports)

4. Старинный Московский тракт сегодня (The old Moskovsky Trakt today)

(I know the road, but I can't locate the exact viewpoint)

5. Дом культуры "Современник" (House of culture Sovremennik/Contemporary)

(June 2023)

6. Из школы в морозный день (Out of school on a frosty day)

7. Городской сад. Встреча (A town garden. Meeting)

8. Окрестности города (Surroundings of the town)

(The hill and a small river? I don't know where it is)

See also related notes:

• Angarsk: 40 years of the Angarsk Construction Department (1948-1988) (2023-09-06)
• Angarsk: 12 photos from 1975 (and 2023) (2023-08-07)
• Angarsk: 10 photo card set from 1969 (and 2023) (2023-07-26)
• Angarsk: 10 panoramic photo set from 1969 (and 2023) (2023-07-13)
• Angarsk: 16 photo card set from 1986 (and 2023) (2023-07-01)
• Angarsk: 12 photo card set from 1974 (and 2023) (2023-06-01)

Image albums:

• Angarsk

Samsung NX by megapixels

Samsung NX mirrorless cameras (2010-2015) grouped by the number of megapixels.


14.6MP APS-C

Samsung NX10 (2010)
Samsung NX5 (2010)
Samsung NX100 (2010)
Samsung NX11 (2010)


20MP APS-C

Samsung NX200 (2011)
Samsung NX20 (2012)
Samsung NX210 (2012)
Samsung NX1000 (2012)
Samsung NX300/NX310 (2013)
Samsung NX300M (2013)
Samsung NX1100 (2013)

Samsung NX2000/NX2020/NX2030 (2013)

Samsung Galaxy NX EK-GN120 (2013)
Samsung NX30 (2014)

Samsung NX3000 (2014)

Samsung NX3300 (2015)

20MP 1"

Samsung NX Mini (2014)


28MP APS-C

Samsung NX1 (2014)
Samsung NX500 (2015)

See also related notes:

• Samsung NX2000: cheap 20MP camera, welcome (2023-07-05)

TrendVision TDR-719S: date-time and GPS module

I have been using the TrendVision TDR-719S dash cam since 2016. Not so long ago, it started erasing the settings. And now it occasionally resets the date and time.

The TDR-719S was supplied with a dedicated GPS module:

It should be connected between the power cable (microUSB) and the dash cam itself. I initially did not install it because I did not need the GPS features (speed/location on video, speed cameras alert). Now I had to install it, but only for the automatic date and time synchronization.

There is no problem with Week Number Rollover (WNRO), the date is correct.

This dash cam is very problematic, I only put up with it because of the good video quality.

See also related notes:

• TrendVision TDR-719S: пять лет эксплуатации (2022-10-21)
• GPS и проблема Week Number Rollover (WNRO) (2019-04-18)
• Мой новый регистратор TrendVision TDR-719S (2016-10-20)

Image albums:

• Video

Noname Pentax K (A) - Sony NEX adapter with the aperture control

I use the K&F Concept adapter to mount Pentax K lenses on the Sony a7c. It's not bad, but it has two drawbacks: self-disassembling construction (I tightened the connection screws several times) and a mounted lens is rotated relative to the camera (but very small).

But I also have a [Chinese] noname Pentax K (A) - Sony NEX adapter as a spare:

Unlike other nonames, this adapter has aperture control (important to me):

Unlike the K&F Concept adapter, the lens is positioned without rotation relative to the camera. This is a good thing.

The aperture control ring is clickless. Sometimes that's good, but I'm not used to it.

But I noticed two bad things.

First, the aperture control has too short a travel:

As a result,  you can't close the aperture to f/22 or even f/16 with many lenses. Yes, with full-frame digital cameras this is very rarely necessary (because of diffraction), but still.

Compare the maximum travel with the K&F Concept:

And with the Samsung MA9NXK adapter (for NX cameras):

Second, the adapter is too thick. I think it's 0.1mm thicker than it needs to be. This is really bad. It is impossible to focus to infinity with the adapter.

That's why I don't use this adapter.

See also related notes:

• External optical viewfinder (35mm): Accuracy (2024-10-11)
• Pentax Auto Extension Tube Set K: Tube #3 (26mm) (2024-06-06)

Image albums:

• Lens accessories

Fixing the rubber grip of the Ricoh GR

On my Ricoh GR, the rubber grip (under the thumb) came loose and started to detach. Gluing it on didn't help, because the grip was expanded and wouldn't fit.

To fix I had to completely remove it from the camera:

And removed glue residues.

Next I put the grip in "Галоша" (Нефрас C2-80/120, some kind of petroleum solvent).

First for 1 hour, then dried. Not enough, still too big. Then another 30 minutes, dried. Now the right size of the grip.

I used 0.17mm 3M (300LSE 9495LE) double-sided adhesive sheet to attach the grip to the camera.

It's been a while, the grip sticks well to the camera.

See also related notes:

• Ricoh GR: типичные проблемы (2022-06-21)
• Ricoh GR: субъективные впечатления (2014-03-19)

Image albums:

• Ricoh GR

Philips 160 (2005): pseudo-color display

There was a time when a color display was a sign of a good mobile phone. But there were also tricks for very cheap models.

This is the Philips 160 (2005, not to be confused with the E160) in the middle. On the left is my old practical Philips Xenium 9@9++, and on the right is the very elegant Nokia 6100.

The special thing about the Philips 160 is that it has a black and white screen.

But when the backlight is on you can see the colored background, giving the illusion of a color screen.

I would like to point out that this trick worked and this phone looked more interesting than the usual cheap monochrome models.

See also related notes:

• Эх, мобильные телефоны... (2014-03-07)

Image albums:

• Mobile

Pentax M 200/4: on the full-frame sensor

I have the Pentax M 100/4 (a manual focus lens pictured on the right):

It's relatively small.

I tried it on my Samsung NX500 (1.5 crop, 28Mp). When focused accurately, the Pentax M 100/4 was better than the Samsung NX 50-200/4-5.6 III.

Although I don't like long focal lengths,  I also tried the M 100/4 on a Sony a7c (FF, 24Mp). And it turned out pretty good for its age.

A birdie:

Cropped 1:1.

Out of focus:

The main problem, of course, is the manual focusing, which must be accurate to get a good result.

See also related notes:

• My Pentax lenses (+Takumar) (2023-02-09)
• Pentax M 200/4 (2016-06-08)
• Samsung NX 50-200/4-5.6 III ED OIS: впечатления (2014-01-31)

Image albums:

• Pentax
• Pentax M 200/4

IBIS focal length for zoom lenses

To use In-Body Image Stabilization (IBIS) with non-electronic lenses, the focal length must be specified in the settings. What about zoom lenses? It is difficult to adjust the setting after the focal length changes.

So it's easier to set a focal length once, but what is the best? An attempt to calculate the optimal focal length: Selecting IBIS Zoom Focal Length

For example, the Variozenitar 25-45/2.8-3.5 lens:

It gives an optimal focal length of 32-35mm. Previously, I chose 35mm (on the Sony a7c) without these calculations.

See also related notes:

• Вариозенитар 25-45/2.8-3.5 (2022-12-23)
• Sony a7c: поддержка неэлектронных объективов (2022-04-26)

Image albums:

• Photo

Ricoh GR: Continuous mode and raw (DNG) shooting

The continuous shooting mode of the Ricoh GR is quite strange when shooting in raw (DNG).

1. It only takes 4 shots in a burst when you hold down the shutter button. To repeat, you have to wait for processing and recording (quite a long time!) and press the button again. I sometimes take at least 10 shots for stacking, and this behavior is very inconvenient, and also increases the probability of significant camera movement between series of shots.

2. This series of 4 images is shot at about 8 frames per second.

3. In the ISO Auto and Auto-Hi modes, the minimum value is ISO400 instead of ISO100.

4. Although you can manually select ISO100.

See also related notes:

• Ricoh GR: субъективные впечатления (2014-03-19)

Image albums:

• Ricoh GR

Sony a7c: readout speed (video mode)

I measured the sensor readout time of the Sony a7c in photo mode when using Silent Shooting (full electronic shutter). Now it's time to explore the video modes.

The methodology is the same: a fast blinking (500Hz) LED is recorded. One pair of lines (dark line and light line) is 2 ms of the sensor reading.

1. Full-frame width, 4K 25/24 fps [PAL/NTSC]

About 12.4 pairs, 24.8ms.

2. x1.2 crop width, 4K 30 fps [NTSC]

About 8.6 pairs, 17.2ms.

3. Full-frame width, Full HD 25/50/100 fps [PAL]

About 4 pairs, 8ms.

4. Full-frame width, Full HD 24/30/60/120 fps [NTSC]

About 3.6 pairs, 7.2ms

5. APS-C, 4K 25 fps [PAL]

About 7.9 pairs, 15.8ms

6. APS-C, 4K 24/30 fps [NTSC]

About 6.9 pairs, 13.8ms.

7. APS-C, Full HD 25/50/100 fps [PAL]

About 3.9 pairs, 7.8ms.

8. APS-C, Full HD 24/30/60/120 fps [NTSC]

About 3.4 pairs, 6.8ms.

Reading in 4K modes is rather slow.

You can see that Full HD modes do not use the same sensor area as 4K, it skips lines. This causes a lot of aliasing, so I find Full HD on the Sony a7c useless.

The value of sensor readout speed is very important for software stabilization with Gyroflow (at least in 4K). It is necessary to always enable "Rolling shutter correction" and set "Frame readout time".

An inaccurate value or a deactivated correction will not allow to achieve a good stabilization.

See also related notes:

• Gyroflow v1.6: Important update for Sony cameras (2024-12-28)
• Sony a7c: How to get better results with Gyroflow (2023-06-27)
• Sony a7c: readout speed (photo mode) (2023-03-25)

Image albums:

• Sony a7c

Pentacon 30/3.5 (M42x1)

The only East Germany lens I had was the Carl Zeiss Jena DDR Flektogon 35/2.4. I didn't like it, preferring the Mosler Fotoguard (Tokina) 35/2.8 and the Pentax K 35/3.5. Now I have another one from East Germany. This is the Pentacon 30/3.5 with M42x1 mount.

PENTACON 3.5/30:

German Democratic Republic:

This lens is a later version of the older Meyer-Optik Görlitz Lydith 3.5/30 lens, which is interesting for its simple retro-focus optical design without cemented elements. There are only 5 elements in 5 groups (looks like a retro-focus Ernostar).

The Pentacon has the same optical design 5/5 (source):

Mine is the latest Pentacon 30/3.5 with a green ft. scale (from the 1980s, as far as I know).

Earlier Pentacon versions had a red one.

This is a preset aperture lens. The aperture ring is single, but it's outer part can be slid forward to set the limit of the aperture closing.

It locks at the following positions: f/3.5, f/4, f/4.8 (intermediate), f/5.6, f/6.7 (intermediate), f/8, f/9.5 (intermediate), f/11, f/16, f/22. The aperture ring rotates from f/3.5 to the locked value without clicking.

A 10-blade aperture, but not round in shape.

The filter thread size is 49mm. This lens is quite small.

The minimum focusing distance is about 30-35cm, which is good for a non-modern lens.

I liked this lens. It doesn't provide very good resolution over the entire frame (on the Sony a7c, FF 24MP), but it has other interesting features. And it's an inexpensive lens. Perhaps it is unpopular because of the name (not Meyer-Optik) and the f/3.5 aperture.

By the way, there is a modern remake version called the Meyer-Optik Görlitz Lydith 30/3.5 II, but it's quite expensive.

See also related notes:

• Meyer-Optik Helioplan 40/4.5 (M42x1/45.5): Simple dialyte lens (2024-05-09)
• Lenses without cemented elements (2023) (2023-10-12)
• Pentax K 30/2.8 vs Pentacon 30/3.5 (2023-10-10)
• Pentacon 30/3.5: My experience [5/5] (2023-08-04)
• Pentacon 30/3.5: My experience [4/5] (2023-08-03)
• Pentacon 30/3.5: My experience [3/5] (2023-08-01)
• Pentacon 30/3.5: My experience [2/5] (2023-07-31)
• Pentacon 30/3.5: My experience [1/5] (2023-07-29)
• Molykote 33 Light: application for lenses (2023-07-21)
• Pentacon 30/3.5 (M42) and Pentax M42-K Adapter (2023-05-31)

Image albums:

• Pentacon 30/3.5