Canon EF 70-300mm f/4.5-5.6 IS DO USM

Tuesday, October 13th, 2009

This weekend I took the Canon EF 70-300mm f/4.5-5.6 IS DO USM out for a spin. The DO stands for “Diffractive Optics” which makes the lens a little sharper and a lot more expensive than the regular Canon EF 70-300mm f/4.5-5.6 IS USM lens. There were some nice photos like this Yellow-rumped Warbler:

However, it’s still not sharp enough for my taste, as seen when you zoom in:

Where are the EF-S L Lenses?

Sunday, October 11th, 2009

One of the promises of the EF-S lens mount was that the lenses could be smaller, lighter weight, and cheaper than full frame lenses. What happened?

While there are a dozen or so EF-S lenses on the market, and they are indeed smaller and cheaper than their full frame cousins, they’re all pretty low-end lenses. All the DO and L-series lenses are full frame lenses, which means I’m carrying a lot more weight than I’d like (and I could really feel that this morning at Jamaica Bay).

Canon EF 70-300mm f/4.5-5.6 IS USM

Saturday, October 3rd, 2009

I’m still looking for a good, general purpose lens with an emphasis on nature shots so I rented a Canon EF 70-300mm f/4.5-5.6 DO IS USM for 10 days. That was too long. Within 20 minutes, it was obvious this was not a good lens. It’s incredibly blurry at all lengths from 70-300mm and all subject distances. It’s decidedly inferior to the cheaper Tamron 28-300, which, while not satisfying me, does well on at least some subjects. If the Canon works on anything, I didn’t find it. Besides general lack of sharpness, it also had very poor close focus and was too long at the short end to do decent portraits. If this lens is good for anything, I didn’t notice it.

The results are vaguely plausible if you reduce the size of the image, which tends to sharpen things up:

three turtles

sRGB or Adobe RGB

Thursday, August 20th, 2009

I shoot raw with an EOS 50D. I display my pictures pretty much exclusively on the Web as JPEGs, and almost never print them. I import, edit, and catalog raw files in Adobe Lightroom 2.4 on a Mac with OS X 10.5. Of course many people who view my pictures use Linux and Windows as well.

What color space should I choose? sRGB or Adobe RGB, and when does this make a difference?

Tamron Update

Tuesday, August 4th, 2009

I was reading Arthur Morris’s blog today when I noticed that he was shooting with wildly different settings than I was. He seemed to be using a wide open aperture, and a relatively high 400 ISO even in sunlight, while relying on the camera to eliminate grain. This let him shoot with shutter speeds as fast as 1/2000 of a second. He had much better lenses than I did, but I still thought it might be worth a try, so I took a quick spin around the ponds at Mason Park in the late afternoon and see how this did. My lens would only open up to f/6.3 at 300mm–his could get as wide as f/4–but it did make a big difference as seen in this photo of a Western Bluebird:

Western Bluebird
Tamron 28-300 Di VC on an EOS 50D body, ISO 400, f/6.3, 1/2000s


The Best Walk-around Zoom Lens for a Canon DSLR

Sunday, July 26th, 2009

I’ve had it for about six months now and given it more than a fair shake, but ultimately I’m not happy with the Tamron AF28-300mm F/3.5-6.3 XR Di LD Aspherical (IF) I got for my primary lens for the EOS 50D. When I put this lens on, I want to be able to shoot at the long end, and I spend a lot more time there than at the short end. Unfortunately it’s just not nearly sharp enough for my tastes at 300mm. Even on a tripod with image stabilization turned on, it needs a shutter speed below 1/400s, ISO no bigger than 200, and aperture f/8.0 to f/11.0 or thereabouts to achieve adequate sharpness. That’s just too limiting. Even then, it’s far from perfect. I’ve gotten a few good shots with it like this Snowy Egret in Mason Park in March, but that’s about it:

Snowy Egret perched

Outside direct sunlight, it really doesn’t perform well at all. In fact, this image stands out precisely because it is so sharp. By contrast, I routinely get images that sharp while handholding my non-stabilized Canon EF 100mm f/2.8 Macro USM, like this Great Blue Heron from San Joaquin a few months later:

Great Blue Heron close-up

Most of my Tamron shots end up looking like this American White Pelican from the Salton Sea instead:


So I think it’s time to look for a new general purpose zoom lens. What are my options?