Spots at f/22

It might be time to clean the sensor of my camera again. The circles in the photo above are the spots I removed in Lightroom. They’re caused by little specks of dirt or dust on the camera sensor.

Thankfully they’re really only visible when shooting with a closed down aperture like f/22. At f/8 I see nothing! The aperture of a lens describes how big the hole in the lens is that lets light in to the camera sensor or film. Paradoxically, small f numbers are big holes, so f/1.8 lets in lots of light, while f/22 creates a tiny hole and not a lot of light gets through.

Even if you never take the lens off your camera, you might still get spots on your sensor. A zoom lens has bits that go in and out. Air goes in and out and there’s a (tiny) chance that dust will get sucked in. Dust in the lens itself is nothing to worry about as it’ll never show in photos but if you shoot a lot at small apertures like f/22 you can clean your sensor.

It’s actually not that hard to clean the sensor. Last year I wrote a blog post on how to clean your camera sensor including a video and step by step instructions. I’ll probably get around to that this week again. Go have a look if you see spots, or go see a doctor if you’re not looking at a photo at the time …

Tethered shooting Android apps for Canon and Nikon DSLRs

I discovered Helicon Remote a few days ago. It allows you to hook your Android phone to a Canon or Nikon DSLR via the camera’s USB port and control many aspects of photo taking. It even has live preview on the phone screen which is a nice bonus.

The app itself is free to download but is limited in that it won’t allow you to shoot RAW images. It also doesn’t restore the camera settings when you shut it down so you may need to fix those after using it. If you register it by handing over $38 (discounted price, it’s normally $48!) you’ll be able to make RAW photos.

There is also the free remote release app by Chainfire and his (much) more advanced DSLR Controller costing only €7.13 that looks to be similar to the Helicon app but more reasonably priced.

I tried the Helicon app with my SGSII, an OTG USB cable and my Canon 40D. Images are stored on your phone just in case you’re wondering where they’ve disappeared to after disconnecting everything!

The new Canon: Canon 5D

Luminous Landscape published their impressions of the new Canon 5D which was announced a few days ago. Ken Rockwell has compared the spec list to that of the Canon 20D with some surprises!
Bob Atkins compares the 20D and 5D too. Some of the features of the 20D that are missing in the 5D ares ones I use – notably the built in flash and spot meter. Sometimes it’s just too much bother getting the 580ex out of the bag, and the on-board flash is sufficient!

Canon IS Lenses – worth it?

Bob Atkins discusses Canon IS Lenses in this article. He asks is it worth the extra cost?
He also asks if it beats an L series lens which is all academic to me as I’m not going to be spending that much money on a single lens any time soon!
Lovely example shots showing the strengths of both types of lens.
I’m waiting on my Sigma 18-200, el cheapo, but “it’ll do the job” I hope!

Digital SLR cameras: Canon Digital Rebel and Nikon D70s

Good run-down of the Canon Digital Rebel and Nikon D70s in this article by Philip Greenspun.

Digital single-lens reflex (SLR) cameras are the standard tool for serious photographers. With the recent introduction of cameras such as the Nikon D80 and the Canon Digital Rebel XTi the market for digital SLR cameras has expanded tremendously. A point-and-shoot compact digital camera can offer reasonably good image quality but a digital SLR, which usually looks a lot like an old standard 35mm film camera and may use the same lenses, offers the following advantages:

* accurate, large, and bright optical viewfinder
* fast operation and large controls
* excellent image quality in low “available” light situations when it is necessary to use higher ISO speeds
* interchangeable lenses