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2023-03-29

Constantly charging phones: swollen batteries

There is a task, for which I have been using different [unneeded] Android phones. The phone is constantly running an application and constantly charging for many months.

And this is very bad for phone batteries. The result of such use:



These are Lenovo A789, Samsung Note, Samsung Note 3 batteries: 



They all swell because of constant charging. But at least they are removable and can be replaced.

Worse is the Huawei Ascend Mate 7, which has a non-removable battery:



The swollen battery caused the screen to separate from the body (reminds me of my old Apple MacBook Pro A1211, whose battery also swells).


The Samsung Note 3 is currently being used for this task, but the battery has been replaced. I have several.

2023-03-27

About Angarsk (TM-1957, in Russian)

The magazine article "A town in the taiga" (in Russian language) about Angarsk, Irkutskaya oblast. It was printed in the Техника молодёжи (Tekhnika Molodezhi, "Technology for the Youth") magazine 1957, #4.





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2023-03-25

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 photofor 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 1/640s 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). By the way, image stabilization can help prevent rolling shutter caused by small movements of the camera.

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.



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2023-03-23

Pulkovo Airport (June 2004)

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


 


Pentax Optio 450 (4MP, 1/1.8").



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2023-03-21

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.

2023-03-19

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:





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



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2023-03-17

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.

2023-03-15

How to put on a camera strap

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


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



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2023-03-13

Baykal Port (2006)

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



Higher resolution: 7274x2985 5025.2KB

Pentax *ist Ds (1.5x crop factor, 6MP) + unknown manual focus lens



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2023-03-11

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.

2023-03-09

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) or 990NZ78R60000. 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.



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2023-03-07

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.

2023-03-05

Pentax DSLRs by megapixels

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


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 (CMOS)

Pentax K-x (2009)
Pentax K-r (2010)


14.6MP APS-C (CMOS)

Pentax K20D (2008)
Samsung GX-20 (2008)
Pentax K-7 (2009)


16MP APS-C (CMOS)

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 (CMOS)

Pentax K-S1 (2014)
Pentax K-S2 (2015)


24MP APS-C (CMOS)

Pentax K-3 (2013)
Pentax K-3 II (2015)
Pentax K-70 (2016)
Pentax KP (2017)
Pentax KF (2022)


26MP APS-C (CMOS)

Pentax K-3 III (2021)
Pentax K-3 III Monochrome (2023) - no color [Bayer] filter


36MP Full-frame (CMOS)

Pentax K-1 (2016)
Pentax K-1 Mark II (2018)



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2023-03-03

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.

2023-03-01

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.



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