Inconclusive?
Donna and I went over to Wilde Lake for about 45 minutes this evening. I wanted to do yet another test after getting my XTi body back from a friend. I shot with the XTi body, the 70-200 (with and without the 2X converter) and with Donna’s 70-300. Of course, I waiting too long in heading out the door, and the lighting was far less than optimal for good tests. But, we shot anyway, and I wanted to share the results — even if the testing was flawed.
This first picture of a Green Heron was taken with the 70-200mm. The ISO was 400, and the exposure was 1/50 sec @ f/2.8. Focal length was 200mm and I was hand-holding for this shot, with no flash. I was at very close range, and, as I’ve mentioned, this is not where I’ve been having problems. Frankly, I think it’s amazingly sharp! So, moving right along …
Here’s our friend, the Great Blue Heron. I’m using the 70-200 plus the 2X for this one. Exposure was 1/60 sec @ f/5.6 — hand held. The pop-up flash is on just to get a little catch-light in the bird’s eye. It looks great on the web. Lousy in print. But, all things considered, it looks better than similar images I’ve made with the 40D using this lens combination. More light would likely have made even more of a difference.
Now I’m using Donna’s 70-300mm lens. It’s a bit later, so there’s less light, and I’ve pushed the ISO up to 800. Exposure is 1/60 sec at f/5, with a focal length of 210mm and the flash was turned on for the catch-light. Again, I’m hand-holding. This one looks real good on screen, and is just passable in print (see my update comment below regarding print quality).
So, what should I conclude from all this? I haven’t got a clue. Both cameras seem to do alright with the 70-300. So, is it a lens problem, a body problem with the 40D, or a little of both? I really should do some more scientific testing, obviously, but it seems that the XTi is producing sharper images with the 70-200.
Post Revisions:
- 2 October, 2008 @ 9:33 [Autosave] by Geren
- 28 September, 2008 @ 22:32 by Geren
- 28 September, 2008 @ 21:58 by Geren
- 28 September, 2008 @ 21:58 by Geren
- 28 September, 2008 @ 21:58 by Geren
- 28 September, 2008 @ 21:57 by Geren
- 28 September, 2008 @ 21:56 by Geren
Did you use the 2x converter on all the shots…………some lenses work better with the 1.4x……….just a suggestion.
I only have the 2X, but, it’s supposed to be “matched to” or “designed for” this lens. I guess I could rent a 1.4X for a couple of days to see. But, at that point, I’m at basically a 300mm lens. At that point, the 70-300 f/4.5-5.6 would serve me just as well — maybe better.
BTW, I have to say that I looked again at the print from the 70-300 (bottom image here), and, if you don’t stick your nose right up to it, it looks very good. Not as good as the image of the Green Heron (top image here), but still very nice.
I also have tried working with some other RAW converters that are supposedly “better” than LR2/ACR, including Bibble and CaptureOne v.4. Bibble was pretty disappointing, considering the build-up people have given it. CaptureOne is pretty intriguing, though I can’t get certain aspects to function as expected in the trial version — and I’m not really willing to plunk down $150 to get the full version just to see if I like it.
Well from my end and on my monitor……..the top image looks FANTASTIC…….
The top image is fantastic (from a technical standpoint — it’s super sharp). It’s not a problem image. I was close to my subject — maybe 15 feet away). It’s the two lower images that are the “issue” shots. In the middle picture, the GBH is maybe 150 feet away from me; the bottom shot, between 75 and 100 feet off.
I’m going to have a large (16×20) print made of each image, and mount them at a “normal” viewing distance and see how I feel about them.
Could it be that you’re getting softness just from the 1/50-1/60 shutter speed forced by turning on the flash? Even with IS, I’d never expect to get tack-sharp handheld at those focal lengths at those speeds.
Well, the first picture is tack-sharp at 1/50th with no flash. In the second and third pictures, the flash isn’t really contributing anything other than a catch-light in the eyes. Exposure was the same with or without. The flash does not force the shutter speed down to 1/60th — flash sync is up to 1/200th on the XTi. And, the results really haven’t been any better with higher shutter speeds.
Regardless … I agree that the low shutter speed isn’t helping me with overall sharpness in these images. But, I know the difference between blur due to camera shake and softness due to bad focus. The reality is that there are at least a couple of things at play here. One is probably the 2X converter. Even though I have the “II” variant, and that adds more glass and loses me two stops. More glass decreases sharpness, especially in teleconverters — even the good ones.
Second, the image stabilization that allows me to hold the lens relatively steady adds at least two more lens elements that may not be necessary in a non-IS design. Add in the fact that these additional elements are in motion, shifting around and changing their angle relative to the sensor plane, and there’s the possibility that they could shift during exposure, and there’s another chance for softening of focus, or that the IS could actually add blur.
Bottom line is that this is probably the wrong kit for this kind of photography. The 70-200mm f/2.8L IS lens is wonderful by itself for general shooting. It was a fabulous wedding and long portrait lens. It’s great for general wildlife and nature shots. It’s awesome for shooting live performances, And, it’s got lovely bokeh. But, for photographing birds, unless I can get in close like I could with the Green Heron, it’s just not the right lens for the job — basically, I’m just expecting far too much.