Sony a7c: readout speed (photo mode)

I wanted to measure the readout time of the Sony a7c (24MP FF) sensor in the Silent Shooting (fully electronic shutter) mode. I had already done this with the Samsung NX500 (for photo, for video) using guitar strings and a 100Hz (50Hz powered) strobe.

This time for the Sony a7c I decided to use a fast blinking LED with an NE555 pulse generator.

The frequency was set to about 500Hz. There is some inaccuracy, but at this frequency it is not that important.

The period (LED off and LED on) is about 2ms. Since the readout of the sensor is much longer, there will be multiple pairs of lines (dark line and light line) visible in the image. The number of line pairs must be multiplied by 2ms to calculate the readout time.

To measure this, I used a tripod to photograph (in ARW) an out-of-focus reflection of the LED at a shutter speed of 1/640 in complete darkness. I did not test the video recording this time (maybe later).

A total of 4 photo shooting modes that affect the readout time in the Silent Shooting mode (fully electronic shutter) of the Sony a7c:

1. Full-frame 14-bit mode

Main (for ARW) but slowest reading mode.

About 31 pairs, 62ms, 1/16s. Very slow.

2. APS-C 14-bit mode

About 20.4 pairs, 40.8ms, 1/25s. Smaller area means faster reading.

3. Full-frame 12-bit mode

There is no explicit setting to switch between 14-bit and 12-bit mode on the Sony a7c. Normally 14-bit is used, but when [lossy] compressed ARW and continuous shooting are enabled together, the camera switches to 12-bit mode.

The 12-bit mode is also used when shooting in JPEG only.

About 17.7 pairs, 35.4ms, 1/28s.

4. APS-C 12-bit mode

About 14.6 pairs, 29.2ms, 1/34s. Fastest reading.

Summary:

The Silent Shooting mode of the Sony a7c has a rather long readout time:

FF 14-bit: about 1/16s (62ms)

APS-C 14-bit: about 1/25s (40.8ms)

FF 12-bit: about 1/28s (35.4ms)

APS-C 12-bit: about 1/34s (29.2ms)

This is far from the capabilities of a mechanical shutter (x-sync 1/160 for the Sony a7c). Although it is possible to use it (I use it very often), but be aware of potential artifacts from camera or object movement (rolling shutter) and artificial lighting (banding).

Visual readout time measurement lets to know if 12-bit or 14-bit reading mode is being used. I have checked and made sure that when shooting in [lossy] compressed ARW without a continuous drive, the 14-bit reading mode is used. But when shooting in JPEG only, the 12-bit reading mode is always used.

See also related notes:

• NE555 pulse generators (now 4 samples) (2023-02-21)
• Sony a7c: шумы, электронный затвор (2022-06-17)
• Samsung NX500: "полнокадровый" FHD и кропнутый UHD (2016-04-27)
• Samsung NX500: механический и электронный затворы (2016-04-13)

Image albums:

• Sony

Pulkovo Airport (June 2004)

St. Petersburg Pulkovo Airport (LED/ULLI), June 2004.

 

Image albums:

• Историческое

Cheap T2-M42 adapter and Mosler Photoguard 35/2.8

I bought a cheap T[2]-M42 adapter for the Mosler Photoguard 35/2.8 lens (which now has an adapter for the Pentax K).

But I couldn't get it fully screwed onto the lens. There is a clearance, therefore it is impossible to focus to infinity.

The end of the lens rests on the internal of the adapter.

For comparison, here is the adapter for Pentax K:

But the T[2]-M42 adapter sits on the Five Star 500/8 lens with no problems.

Some adapter modification is required.

See also related notes:

• Mosler Photoguard 35/2.8 (2022-11-01)
• Таир-3C и Five Star 500/8 (2022-05-26)

Image albums:

• Фотосъемка

Stanley Kubrick’s Barry Lyndon and special lenses

A special and very expensive the Zeiss Planar 50mm f/0.7 lens allowed Stanley Kubrick to film indoor scenes of Barry Lyndon (1975) by candlelight only.

The Planar 50/0.7 without a front mount converter (narrower angle of view):

The Planar 50/0.7 with a front mount Kollmorgen converter as 36.5/0.7 (wider angle of view):

More info:

OMAGGIO ALL'IMMORTALE  KUBRICK ED AL MITICO PLANAR 50mm f/0,7 (in Italian, recommended reading)

Two Special Lenses for "Barry Lyndon" by Ed DiGiulio (President, Cinema Products Corp.)

Photographing Stanley Kubrick’s Barry Lyndon

Ironically, a similar technical result (filming indoor scenes by candlelight only) can now be easily achieved with amateur digital equipment.

Image albums:

• Историческое

GM Special Lubricant High Temperature: application for lenses

I maintained the Юпитер-3 (Jupiter-3) 50/1.5 lens with applying GM Special Lubricant High Temperature (12345879).

There were some doubts about very cold weather handling. But this winter I shot outside with this lens and the focusing was still quite smooth. And the smell of grease has almost disappeared. So I will continue to use this lubricant in lenses.

See also related notes:

• Юпитер-3 (50/1.5): частичная переборка (2022-05-01)
• Смазка GM Special Lubricant High Temperature (12345879) (2021-03-01)

Image albums:

• Масла

How to put on a camera strap

I had previously used the option shown on the left (which is generally the manufacturer's recommendation).

(source)

But I have switched to the option on the right for my photo cameras.

Image albums:

• Фотосъемка

Baykal Port (January 2006)

Lake Baikal, the source of the Angara River, Baykal Port. January 2006. The horizontal panorama:

Higher resolution: 7274x2985 5025.2KB

Image albums:

• Историческое

Two section tripod extender

There's one more enhancement to my SLIK PRO 500DX tripod (besides the plate adapter). This is a two section aluminum tripod extension tube:

It is for use between a tripod and a tripod head.

1/4" mounting for a head. 3/8" or 1/4" (with the included adapter) mounting to a tripod.

Two sections:

Extra height from 22 to 39 cm. Of course, at full height with the extender the tripod loses stiffness significantly, but sometimes this is acceptable.

See also related notes:

• Штативная площадка с держателем (подобно "Arca Swiss") (2022-08-25)
• Штатив SLIK PRO 500DX + SH-705E (2014-05-02)

Image albums:

• Фотосъемка

990NZ-78R60-000: Radius arm mounting guards for Jimny 2018+

There is a Russian accessories catalogue for the Suzuki Jimny 2018+:

There I found radius arm mounting/bracket protection/guards with the part number 990NZ-78R60-00.

This is a typo, the correct part number is Suzuki 990NZ-78R60-000 (with three zeros). But it is OEM for Russia only. 

The year 2021 is stated, I don't know if this kit is currently in production.

From left to right: rear parts, front parts.

This kit contains four big protective washers for the rear, four big protective washers for the front (including one trim washer), four spacers for the rear, four spacers for the front, and four mounting bolts with four small washers and four nuts.

The installation manual (in Russian language):

Size of the big protective washers: 90x12.4x6 (mm, rear), 84.2x12.4x6 (mm, front).

This protective washers have a larger outer diameter while 80mm is usually used. And the thickness is as much as 6mm, instead of the usual 4 or 5mm.

Size of the spacers: 32.3x12x10 (mm, rear), 38.3x12x10 (mm, front) 

The mounting bolts are M12x1.25 120mm class 10.9.

Looks like the 15541831 (1/55418/31) bolt for Russian heavy trucks.

I am going to install these guards on my Suzuki Jimny [Sierra] 2005.

Image albums:

• Suzuki Jimny

Nokia N73's camera (2006)

The "focus free" cameras of early mobile phones  (for example: 1, 2) were pretty bad even by the standards of those days.

The first phone in my hands that introduced at least some quality results was the Nokia N73.

The sensor size seems to be 1/2.5", it is not too bad for a mobile phone even today. The first decent digital camera I could use, the Canon A60 (2003) had a smaller 1/2.7" (2MP) sensor. The N73's larger sensor is 3MP.

The Nokia N73 has an 5.6mm/2.8 lens (Carl Zeiss Tessar named!) with autofocus, which is of course a noticeable improvement over "focus free" lenses. The 35 mm equivalent focal length is about 35mm (longer than a modern main camera have).

Examples of photos (2007-2009) to demonstrate the level of image quality. All are unprocessed camera JPEGs.

Landscapes:

(Lake Baikal, the Circum–Baikal railway)

(Lake Baikal)

(Ice of Irkutsk Reservoir)

(Lake Baikal)

Closer subjects:

(Honda Stream is stuck)

Difficult lighting conditions:

(the Circum–Baikal railway)

(Kitoy River)

And a bit of history (Irkutsk, August 2008):

The main complaints are not even about the resolution of the N73 camera, but about the specific "digital" colors, which ruin the image.

See also related notes:

• Nokia 6111: работа камеры (2015-02-24)
• Фотоистория (Pentax Optio 450) (2012-12-28)
• 2Мп камера в Nokia 6288 (2007-01-08)

Image albums:

• Мобильные телефоны

Pentax DSLRs by megapixels

Pentax K-mount DSLRs grouped by the number of megapixels.

6MP APS-C (CCD)

Pentax *ist D (2003)

Pentax *ist DS (2004)

Pentax *ist DL (2005)

Pentax *ist DS2 (2005)

Samsung GX-1S (2006)

Pentax *ist DL2 (2006)

Samsung GX-1L (2006)

Pentax K100D (2006)

Pentax K110D (2006)

Pentax K100D Super (2007)

10MP APS-C (CCD)

Pentax K10D (2006)

Samsung GX-10 (2006)

Pentax K200D (2008)

Pentax K-m/K2000 (2008)

12MP APS-C

Pentax K-x (2009)

Pentax K-r (2010)

14.6MP APS-C

Pentax K20D (2008)

Samsung GX-20 (2008)

Pentax K-7 (2009)

16MP APS-C

Pentax K-5 (2010)

Pentax K-01 (2012) - mirrorless, not DSLR

Pentax K-30 (2012)

Pentax K-5 II (2012)

Pentax K-5 IIs (2012)

Pentax K-500 (2013)

Pentax K-50 (2013)

20MP APS-C

Pentax K-S1 (2014)

Pentax K-S2 (2015)

24MP APS-C

Pentax K-3 (2013)

Pentax K-3 II (2015)

Pentax K-70 (2016)

Pentax KP (2017)

Pentax KF (2022)

26MP APS-C

Pentax K-3 III (2021)

36MP Full-frame

Pentax K-1 (2016)

Pentax K-1 Mark II (2018)

See also related notes:

• 6Мп цифрозеркальные камеры Pentax: от *istD и *ist Ds до K100D/K110D (история) (2018-04-07)

Samsung NX300: AMOLED degradation

I accidentally got a Samsung NX300 camera. It hadn't been used for a couple of years, which probably led to some LCD AMOLED screen problems.

At first there were "migrating" pink spots on the screen. Then the screen dimmed and turned brown.

1. Now the images on the screen look sepia. The highlights are blown out.

It looks very bad, although the photos themselves have no problems (it's the same camera JPEG):

2. Ghosts ("shadows") of controls, text messages ("No Image File", "MENU") appear on the screen.

This camera JPEG is shown:

3. In bright sunlight it is now impossible to see the image on the screen even for framing. The two photos above had to be taken "blind" by roughly pointing the camera in the desired direction. Since the NX300 doesn't have a viewfinder.

I don't know what that is or why. Changing or resetting the settings doesn't help. It looks like AMOLED degradation. I'm surprised it appeared so early and after the camera has been turned off for a while.

See also related notes:

• Опять Samsung NX300 (2022-10-01)

Image albums:

• Samsung NX

Pentax A 35-105/3.5 (longtime experience)

For a while I had the Pentax A 35-105/3.5 lens:

(From left to right: K 35/3.5, A 35-105/3.5, M 135/3.5)

Pentax DSLR's program modes work with it (because of the A position of the aperture ring), but of course without autofocus. The image quality was quite good, but the lens is uncomfortable to use on the *ist Ds or the K10D. There's some sort of disbalance of weight with the lens. It is hard to handle a camera when rotating two rings of the lens one after the other.

After switching from DSLRs to mirrorless cameras, this lens was completely out of use. But somehow I tested it on a Samsung NX camera and again I was convinced that the image quality was really good for a zoom lens of the time.

This lens hadn't waited for a full-frame camera, I sold it very cheaply a few years ago because of some fungus. I would like to see how it performs on the full-frame camera, but I doubt it will be usable on the relatively small Sony a7c. Again because of that unbalanced weight.

Anyway, the Pentax A 35-105/3.5 is a surprisingly good image lens.

See also related notes:

• Pentax A 35-105/3.5 (2006-12-23)

Image albums:

• Pentax

SZ Viewer A1: Google Play statistics (2022-2023)

Today's install base of SZ Viewer A1 [for Android] (the difference for the year).

Belarus: 282 (-118)
China: 8 (+7)
Eritrea: -

Iran: 9 (-11)
Mali: -
Nicaragua: 6 (-4)
Russia: 10647 (-2632)
Venezuela: 39 (0)
Zimbabwe: 2 (+1)

Other 168 countries/regions: 20094 (+3206)

All 177 countries/regions: 31087 (+449)


These are Google Play statistics: The number of active Android devices on which the app is installed. An active device is one that has been turned on at least once in the previous 30 days.

NE555 pulse generators (now 4 samples)

I already had two NE555 pulse generators to improve the work of the Suzuki Jimny's automatic transmission in the low range of the transfer case. I added two more samples.

I have not yet decided which one to use for further experiments.

See also related notes:

• Sony a7c: readout speed (photo mode) (2023-03-25)

Image albums:

• Электрика и электроника

Holga HL(W)-SSN: on the full-frame camera

I was playing with the Holga Holga HL(W)-SSN (29/8) toy lens on my Samsung NX cameras. I wanted to use a homemade adapter from NX to Sony FE (for my Sony a7c camera), but the adapter appeared to be too bad. Instead, I managed to mount the lens with the tail of some Sony FE extension tubes. I just fixed it with duct tape masking tape. 

But the thickness of this tail is less than required (25.5 - 18 = 7.5mm), so the Holga's focusing ring is set to the closest distance. This caused the optics to move away from the rear aperture plate, making the vignetting more visible at infinity.

And of course the vignetting is very heavy on the full-frame sensor.

Some photos: 1.5 crop (APS-C) and full-frame images.

See also related notes:

• Переходник Samsung NX на Sony E (2022-05-28)
• Holga HL(W)-SSN: объектив-спецэффект за $16 (2014-05-04)

Image albums:

• Фотосъемка
• Sony