Tuesday, October 30, 2007

Digital SLR selection

I have been wanting to buy a digital SLR for a long time now and finally broke down and bought one to take on our last vacation. I had been debating what brand and model to buy for several years and ended up with the Pentax d100Super .

If I were actually making money from my photography it might have been better to go with a Nikon or Canon, but since I currently have no plans to do that, the Pentax seemed a better choice. The choice of the Pentax seemed to be the one that would allow me to grow a small system for the lowest total cost possible.

The fact that the image stabilization is built into the body rather than the lenses allows me to use it with any lens, not just the expensive dedicated IS lenses that Nikon and Canon make. I know that each company is starting to come out with lower priced IS lenses and Sigma now has one but those are still at least $4-600. A lot of money for a gadget to support a hobby.

With the Pentax (as with the Sony/Minolta system) I can buy used lenses dirt cheap and use them with the built-in IS.

There are a few limitations to this that I discovered however. The main one is that the focus screen in the d100 does not make manual focusing very easy. This makes buying manual focus lenses an iffy proposition at this point since I can't be sure that I can keep them in focus all the time. Old manual focus lenses are often vastly cheaper than the new auto-focus versions of the same lenses. There are a few 3rd party focus screen manufacturers that make screens that should make manual focusing easier but they may affect auto-exposure a little and it is unclear whether they might interfere with auto-focus or IS.

Also, the older auto-focus lenses seem much noisier than new ones and some of them may be quite a bit heavier and larger than current lenses. Their coatings may not be as good with digital cameras either.

Still though, I think this will allow me to get the lenses that I want for a few hundred dollars rather than the few thousand that it would take with a Nikon or Canon.

Also, apparently the camera based IS systems should work better with the short to medium lenses that I favor as opposed to the lens based systems that work best with longer lenses. A 28mm f2 should allow me to take handheld photos in very low light. Just the sort of setup that I typically need on vacation for taking pictures inside of dimly lit museums, churches, etc. theoretically the limit should be 1/28th of a second for the lens by itself with the IS system adding about 2 stops for a minimum shutter speed of 1/7th of a second. At 800-3200 ISO this should allow me to shoot handheld in very dim places.