This is a picture of the half moon from early in January 2009. This was taken with a Canon 10D through a Takahashi FS102 refractor at prime focus.

There have been a lot of reports of the 5D’s trouble with bright point lights. I recently updated to the new firmware (version 1.0.7) and took some test shots with the 5D Mark II and a Takahashi FS102 refractor. I also wanted to test out the sensitivity at various ISO values. All these pictures were taken from my driveway on a day with fairly bad seeing and transparency. I got out a ladder and threw a blanket over one of the street lights but it didn’t help much with the sky glow.

I recently had some of my old astrophoto slides scanned with a Noritsu slide scanner so I can put them into permanent storage and finally move into 100% digital photography. I’ve learned a lot about image processing and the tools are much better now than they were when I originally took the photos. There are three major changes that affect the quality: The slide scanner is much better (although the lab gave me JPG files instead of 16bit TIFF files, what the hell?

It’s been at least three years since I’ve done any astrophotograpy but last night I lugged out the equipment and shot a few frames. I only made it out as far as the driveway and the sky isn’t very dark in northern San Diego but it’s amazing what kind of results you can get with a Canon 10D. Traditionally you would use either slide film or a cooled, black and white CCD sensor.

Console video games run on memory restricted environments and even with half a gigabyte of space it runs out quickly. It’s easy to know when you’re out of memory, what we want to know is exactly what approach to take to fix the problem. With all the information available the challenge is presenting the information in a way that gives clear indication of problems while providing enough low-level detail to zero in on individual assets.

Update: the USGS has changed their service and this app no longer works. Plus, I lost the source code after a hard drive crash. Remember - back up your data! Flash, and Flex in particular, has a solid set of tools available ata visualization. When I found that the USGS provided realtime earthquake data as csv files I couldn’t resist building a viewer. It’s based on a traffic map by Nathan at Flowing Data

My Gallery2 embed plugin for MovableType kind of sucked before. It dove right into the SQL database to grab information which makes it brittle if the schema changes. I’ve updated it to use the GalleryEmbed API to grab image blocks. It works a lot better. I also threw in some support for floating thumbnail boxes to make the pages look a little more interesting. I’ve started uploading some macrophotographs into a new album.

Results of performance optimization study on both PowerPC and CoreDuo machines. 100 runs of the same two functions were done and the best time from each is recorded as changed are made to the code and compiler flags. The “Sum” test sums 10,000 vectors (c = a + b). The “Diffuse” test runs a fluid diffusion pass on a 2D array of vectors. PowerPC (G5 1.8Ghz) Change Sum Diffuse Baseline 28ms 48ms Switch to vFloat type 68ms 116ms 'inline' Vector ctor 69ms 128ms AltiVec Vector functions 27ms 62ms 'inline' AltiVec functions 25ms 58ms 'inline' getNeighborSum() 25ms 38ms Hand tune diffuse with vec_madd n/a 23ms -mtune=G5 24ms 22ms -ffast-math=16 24ms 22ms -falign-loops=16 24ms 22ms

While playing around with the Aperture database I decided to try to make something useful. The result is an Automator workflow that looks for duplicate master image names. Here’s the result. Disclaimer: it’s not pretty and the output goes so TextEdit instead of some fancy Cocoa application or Aperture album. Please give it a try and let me know if anything goes wrong. Find Aperture Duplicates v0.1

Most of the time we want more resolution in our images so they can be printed on bigger and bigger formats. However, for web publishing it’s important to have quality downsized version of our images. A question about how Aperture does this was raised on the Aperture discussion group about image downsizing. I used a few test images from Oshyan Greene’s website to find out. Here are the results. It’s hard to tell exactly what algorithm Apeture is using, but it’s probably bilinear filtering since it’s very easy to do using the GPU.