Tag: photography

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New camera: Pentax K20D

I’ve used a Rebel XT for the past 2+ years, and it’s been a great camera for me. I haven’t wanted for megapixels – 8 is plenty for pretty much any print I’ve wanted to make. It shoots fast enough for anything I need to capture. The LCD is tiny by current standards, but I don’t look at it very often – mostly just to check focus and level. It’s worked very well with my collection of M42 screw mount lenses via an inexpensive adapter.

One shortcoming of the Rebel XT is that it only has one adjustment dial that can’t be configured. I mostly shoot with manual lenses in aperture-priority mode, so it would be very nice to be able to configure the dial to adjust ISO. Another odd shortcoming is the lack of focus confirmation for manual lenses. There are manual lens adapters available that have chips to trick the camera into doing focus confirmation, but there’s no reason Canon couldn’t have just enabled it. It also has no sensor self-cleaning function, so I’ve usually got a couple bits of dust on the sensor annoying me.

So, I had a few requirements for a new camera, plus a couple of wishes:

  • More megapixels
  • Bigger LCD
  • Easy/cheap M42 lens adaptation
  • Self-cleaning sensor
  • Focus confirmation with manual lenses
  • At least 2 adjustment dials
  • Dust/moisture seals and in-camera image stabilization might be nice…

I wanted to stick with Canon so I considered a Canon 40D, but it wouldn’t have been much of a megapixel improvement over the Rebel XT. The 50D would have, but it was a bit too expensive. So, I looked at other brands. Olympus and Pentax cameras both adapt well to M42 lenses. The reviews for Olympus’ DSLRs are a bit mixed, but the lens mount can be adapted to a wider variety of old lenses. I liked the idea of a Pentax because they make a few interesting modern lenses, such as a nice 50/1.4 and some odd “pancake” lenses. Even though I mostly use manual lenses, it’s nice to have an autofocus lens for some situations. The K20D had all of the features I wanted, decent reviews, and an acceptable price. I got it, plus a 50/1.4 lens, for what a 50D would have cost.

So far I like it. It’s big and heavy compared to the Rebel XT, but I guess that makes it feel more solid and professional. There are plenty of controls and they’re placed pretty well.

The M42 adapter I got has been a little disappointing. It got stuck on the camera due to an odd spring thing. Without the spring it doesn’t click into place, but at least it can be removed. It seems to work best to attach the adapter tightly to a lens, then just use that lens like a K-mount lens. That would work fine to use a single M42 lens, but I usually want to use several. I could get a few of the cheap adapters and attach them to lenses as needed, but I decided to order an official Pentax adapter to see if that’ll work better.

In the meantime, I’ve mostly been using the FA 50/1.4 lens that I decided to get with the camera. It’s a very nice lens, as good as my 50/1.4 SMC Takumar (but with autofocus for easier cat photography). Here are a couple of the photos I’ve taken with the K20D and FA 50/1.4 so far:

Shirt laundry Oscar takes a break Purple coneflower Alert Penelope

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Image renaming bash script

As part of my photo archiving process I like to first change the image file names from their original nonsense names to something based on the date and time. This way, if I upload a low-res image someplace, such as Flickr, I can easily use its original filename to locate the high-res version in the archives. This also means all of my images have unique filenames.

To batch rename files, I used to use a script called “irename” that I got from varp.net a long time ago. Unfortunately, it would fail to rename images that were taken too close together. Looking at the code, it didn’t include a way to automatically give unique names to images taken really close together. So, I looked at the code to see if I could fix it. It turned out the script was parsing the EXIF info in image files itself – which I guessed an external program could do more reliably. There’s a Perl library and command-line tool called exiftool that does a great job of parsing EXIF info. It even does exactly the sort of image file renaming I wanted to do, but I didn’t want to have to type all this every time:

exiftool -d %Y%m%d_%H%M%S%%-c.%%e "-filename

When you find yourself typing stuff like this at the command line repeatedly, you should put it in a bash script with a name you’ll remember, place that in your “bin” folder, and make it executable. I called my script “camcon” because I didn’t have anything on my system with that name and it sounded easy to remember. Download camcon: camcon.zip

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Digikam-pocalypse

I’ve been using Digikam to organize my photo portfolio into albums and tags for quite a while. I have something like 2500 photos, with a few albums and a LOT of tags. The new version of Fedora comes with KDE 4, which apparently includes a new version of digikam. Normally this would be a good thing – more features, prettier interface, etc. Unfortunately, the new version’s database is a little different, so it’s gotta import photo info from the old database. Sadly, it failed to import mine for some reason, maybe because I have so many tags or photos. It started up fine with just the photos, making a new database from scratch, but my old tags obviously weren’t there.

I thought about just waiting patiently for an update to digikam to see if that’d fix it, but I figured I’d poke around in the meantime. Digikam stores its photo info in a SQLite database, which can be messed with using the SQLite Manager add-on for Firefox. Sounds strange, looks pretty ugly, but it works well enough. SQLite databases are just files so I made a copy of my old database and the new, empty database to work with. The old and new databases looked pretty similar – there are just a few new tables and some tables have new fields. The tag-related fields look exactly the same though, so it’s pretty odd the import failed. I’d hoped to just use SQLite Manager to just copy the old tags tables into the new database, but the image ids were sadly different. All my image names are unique, which meant I could run a query to match up the old and new image ids using the image names as a key, then replace the old ids in the copied-over ImageTags table with the matching new image ids. Complicated, but it worked…

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Fuzzy US Capitol

US Capitol

I’ve been using a Super Takumar 50/1.4 adapted to my Rebel XT a lot lately. I think it’s got a bit of the radioactive yellow thing, which I guess means it sat around a while out of the sun. It’s supposed to go away after exposure to sunlight, but after several months of use and some time in the windowsill it’s still a bit yellowish. It doesn’t really matter with digital because it’s easy enough to adjust the color later.

I forget to stop down the lens a sometimes after using the open aperture for easier focusing. All the stray light, flare, internal reflections and whatnot conspire to make some subjects look pleasantly soft. Seems to be distant subjects, where you’d have the focus at infinity, that look best. So, I tried a few shots of the capitol with the aperture open to 1.4. Bumping up the contrast removes the haziness, and I prefer shots like this in black and white. In color they look like 70s snapshots, which can be nice too.

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Comparing a couple of M42 wide-angle lenses

So, after spending maybe-a-little-too-much time on eBay I’ve got 3 wide-angle M42 screw-mount lenses to choose from. I didn’t intend to get two 28mm lenses, but I bid on a couple of lenses where the descriptions were vague and the photos were out of focus – lucky I didn’t end up with a couple of paperweights I guess. Here they are together with the 35/3.5 Super Takumar I already had, for size comparison:

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