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2024-03-08

Pentax M 100/4 Macro: Samples [1] - FF

Photos taken with the Sony a7c (FF, 24MP) and the Pentax M 100/4 Macro at f/4.











See also related notes:
Posted by malykh в 02:29 0 comments

2024-03-07

Digitizing a film with a digital camera (2006)

When I first started shooting with digital cameras, I also tried to use them to digitize old films.

In 2006 I made a pretty good construction:




It was based on the Pentax *ist Ds (my first DSLR, 1.5x crop factor, 6MP). On the camera was mounted the Industar-61L/Z 50/2.8 with a M42x1 extension tube in between (to increase magnification). 




The lens was combined with other M42x1 extension tubes and slide/film holders.





As far as I remember, I took the holders from an old slide projector Свет ДМ-4Т (Svet/Light DM-4T) or similar.

The frame was illuminated by reflected light of a flash.

I used this construction to digitize slides (i.e. positive films). The result was good. But color negative films required (at that time) too many difficult actions to restore original colors. So in the latter part of 2006, I switched to a flatbed image scanner that could also scan films.

Posted by malykh в 00:03 0 comments

2024-03-06

RockStar/AstrHori 35/1.8 (Sony FE/E): Full-frame lens

This is a non-electronic manual focus full-frame lens for the Sony FE/E mount.



It's called the RockStar or AstrHori 1.8/35. 




It has an unusual design with two filter threads. The "inner" thread is 52mm, it moves back and forth when focusing, but it doesn't rotate. The "outer" thread is 58mm, it doesn't move when focusing, but it does rotate.




If you use a filter on the 52mm thread, you can't use a cap on the 58mm thread at close focusing distance.

The minimum focusing distance is about 29cm, which is good. The hard stop focuses to infinity, which is rare for a Chinese lens.

The aperture has 9 blades:




Also note the yellow tint, this will be an important consideration.

The aperture ring with click stops: f/1.8, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16.

Optical design: 9 elements in 7 groups




This lens (on the right) compared to the Samyang AF 35/2.8 (on the left) and the Cheecar FF 35/1.4 II (in the center):




The lens is quite large and heavy.

Posted by malykh в 00:02 0 comments

2024-03-05

Duplicate fret markers [DIY]

Round stickers:




These stickers duplicate the fret markers on a guitar neck.




Sometimes it comes in handy.



Image albums:
Posted by malykh в 00:03 0 comments

2024-03-04

Pentax K-m vs Sony a7c: Size comparison

The Pentax K-m is a compact, lightweight DSLR with an APS-C sized sensor (1.5x crop factor). The camera is quite small in the DSLR world. But how small is it compared to the full-frame mirrorless Sony a7c?

I mounted the Pentax A 50/1.7 (the smallest Pentax K-mount lens I had) on the K-m and the Samyang 35/2.8 FE (the smallest Sony FE-mount lens I have) on the a7c.





This shows how small the Sony a7c is despite being a full-frame camera. I especially like the absence of the pseudo-pentaprism protruding from the body.

Posted by malykh в 00:00 0 comments

2024-03-03

Noname [OEM] 50/1.1 FF: Samples [1] - FF - f/1.1

Photos taken with the Sony a7c (FF, 24MP) and the Noname [OEM] 50/1.1 FF at f/1.1.











See also related notes:
Posted by malykh в 00:04 0 comments

2024-03-01

Webolog: Common/Combined Log Format analyzer [Java, 2001]

In 2001, I had access to the server logs of a Tonigy website. I tried several ways (at least Moglan, Webalizer, Analog, ALA, and hypermart.net service) to analyze them, but I didn't like the results. So I decided to write my own web log analyzer.

Although I wrote Tonigy in the C language, I decided to use the Java language. Java had a much more advanced standard library than C. In C, even simple string manipulation was too verbose.

I was also writing in Perl at the time, but I was never a fan of that language. I didn't see Perl as a language for anything more complex than a few CGI files.

In 2001 I created an analyzer called Webolog, which I never published. But I used it a lot in my work. It was a command line tool for Java 1.1+. It takes logs in Common or Combined Log Format, extracts data, collects it, and generates a bunch of HTML files (with statistics).

I do not have logs that old, but I found screenshots from May 2001. Funny, they show MS IE as the browser.

Total visits:




"Referers":




Search queries (from "referers"):




It is possible to configure query extraction. The search sites at that time:

===
web.altavista.com q
www.altavista.com q
www.lycos.com query
www.google.com q
www.google.fr q
www.google.de q
www.search.com qt
google.yahoo.com p
search.163.com key
en.os2.org query
===


Browsers used:




And OS used:




Agent data extraction is also configurable with RegEx.

===
; Opera
"Opera/(\S+) \(.*Windows 9(?:5|8).*\)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Windows 95/98"
"Opera/(\S+) \(.*Windows NT 4\.0;.*\)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Windows NT"
"Opera/(\S+) \(.*Windows NT 5\.\d;.*\)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Windows 2000"
"Opera/(\S+) \(.*Linux.*\)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Linux"
"Opera/(\S+) \(.*OS/2.*\)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "OS/2"
"Mozilla/\S+ \(.*Windows 9(?:5|8).*\) Opera (\S+)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Windows 95/98"
"Mozilla/\S+ \(.*Windows 2000.*\) Opera (\S+)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Windows 2000"
"Mozilla/\S+ \(.*Linux.*\) Opera (\S+)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Linux"
"Mozilla/\S+ \(.*Windows 3\.10.*\) Opera (\S+)\s+\[[a-z]{2}\]" "Opera" "Opera $1" "Windows 3.1"

; Internet Explorer
"Mozilla/\S+ \(.*MSIE (\S+);.*Windows 3\.1\)" "Internet Explorer" "Internet Explorer $1" "Windows 3.1"
"Mozilla/\S+ \(.*MSIE (\S+);.*Windows 9(?:5|8).*\)" "Internet Explorer" "Internet Explorer $1" "Windows 95/98"
"Mozilla/\S+ \(.*MSIE (\S+);.*Windows NT 5\.\d.*\)" "Internet Explorer" "Internet Explorer $1" "Windows 2000"
"Mozilla/\S+ \(.*MSIE (\S+);.*Windows NT(?:| 4.0).*\)" "Internet Explorer" "Internet Explorer $1" "Windows NT"
"Mozilla/\S+ \(.*MSIE (\S+);.*Mac_PowerPC.*\)" "Internet Explorer" "Internet Explorer $1" "Mac/PowerPC"

; Netscape Navigator
"Mozilla \(OS/2; (?:I|U); OS/2 Warp\)" "Netscape Navigator" "Netscape Navigator" "OS/2"
"Mozilla/(\S+) \(.*OS/2.*\)" "Netscape Navigator" "Netscape Navigator $1" "OS/2"
"Mozilla/(\S+) \(.*Linux.*\)" "Netscape Navigator" "Netscape Navigator $1" "Linux"
"Mozilla/(\S+) \(.*Macintosh.*68K\)" "Netscape Navigator" "Netscape Navigator $1" "Mac/68K"
"Mozilla/(\S+) \(.*Macintosh.*PPC\)" "Netscape Navigator" "Netscape Navigator $1" "Mac/PowerPC"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*OS/2.*\)" "Netscape Navigator" "Netscape Navigator $1" "OS/2"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*Win9(?:5|8).*\)" "Netscape Navigator" "Netscape Navigator $1" "Windows 95/98"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*WinNT.*\)" "Netscape Navigator" "Netscape Navigator $1" "Windows NT"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*Windows NT 5\.\d.*\)" "Netscape Navigator" "Netscape Navigator $1" "Windows 2000"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*Linux.*\)" "Netscape Navigator" "Netscape Navigator $1" "Linux"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*SunOS.*\)" "Netscape Navigator" "Netscape Navigator $1" "SunOS"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*AIX.*\)" "Netscape Navigator" "Netscape Navigator $1" "AIX"
"Mozilla/(\S+) \[[a-z]{2}\].* \(.*IRIX.*\)" "Netscape Navigator" "Netscape Navigator $1" "IRIX"

...
===


Webolog collects data in a simple database. For simplicity I didn't use a RDBMS. Instead, the data is stored in a ZIP file containing several binary and XML files. Not very efficient, but it was enough.

Then Google Analytics became usable and even popular, so I stopped using Webolog.


p.s. And when I looked at the source of Webolog, I found using the variable name "t" as expected:





See also related notes:
Image albums:
Posted by malykh в 00:01 0 comments

2024-02-29

Olympus E-PL1: Micro 4/3 mirrorless camera (from 2010)

My new old camera: the Olympus E-PL1 with the 14-42/3.5-5.6 lens (28-84mm equivalent).




I mentioned this camera back in 2011. It is exactly this one. I recently got it for free.

It was one of the first mirrorless Micro 4/3 cameras (2010). The crop factor is 2x (with the 4:3 aspect ratio), 12MP.

The camera has simple controls. There is not even a dial except for the mode dial. To change the aperture/shutter speed in manual modes, you should use the up and down buttons.




Surprisingly, the menu is quite powerful, there are many options to customize the camera.

The shutter counter shows about 5500 frames. But there are few problems, typical for old Olympus cameras. However, the camera shoots and is still usable.

I don't see any reason to use the camera for everyday photography, but I hope to test it with some manual focus lenses (via an adapter).

Posted by malykh в 00:00 0 comments

2024-02-27

Pentax K 30/2.8: Samples [1] - FF

Photos taken with the Sony a7c (FF, 24MP) and the Pentax K 30/2.8 at f/2.8.









A sunstar at f/8 (or f/11?)






See also related notes:
Image albums:
Posted by malykh в 00:02 0 comments

2024-02-23

Pentax K 35/3.5 lens (K): Retrofocus wide-angle Tessar



(Pentax K 35/3.5)

This is the direct K-mount successor of the 35/3.5 M42x1 Takumar series (Auto/Super/S-M-C versions, 1959-1975).


(Takumars 35/3.5)

Meanwhile, the 35/3.5 Takumars came as an evolution of the Takumar 35/4 (1957-1959).


(Takumar 35/4, source)

All these lenses have 5 elements in 4 groups. And they are retrofocus versions of the Tessar optical design: a diverging meniscus was placed in front of a Tessar base lens. It defines a character of the lens.

Posted by malykh в 00:01 0 comments

2024-02-21

Loop counter name: "t" vs "i"

It is common in programming to use the variable name "i" as a loop counter. This is an old practice with roots in mathematics (using "i" as index notation, index of summation, etc.). The practice was played up in early versions of Fortran, where the default implicit typing rule is that if the first letter of the name is I, J, K, L, M, or N, then the data type is integer, otherwise it is real.

Of course, when I started programming, I also used the name "i". But if you look at some of my old code, you will see a deviation from the rule.

For example, Tonigy (C language, 2001-2002):




w95k_tvh (C language, 2002):




malykh-geo-ep (Java language, 2009-2010):




Yes, the name "t" is used instead of "i". And there was a reason. Back in the 1990s, my keyboard broke: I had to press the "i" key hard to close the switch. It was very annoying, but I had no money to repair or replace the keyboard right away.

So I tried to minimize the use of the "i" key. And I chose "t" for the variable name (I assumed it meant "temporary").

Although I replaced the keyboard after a while, the habit persisted for a long time.

Today, I don't use the name "t" as a loop counter. Modern programming languages allow direct enumeration of entities without an index. Therefore, the name of the loop variable should be related to the entity type. And only for a simple index (in a clear case of use) I write the name "i".


(some Scala code of SZ Viewer)

Posted by malykh в 00:03 0 comments
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