digital zoom with 0620?

i was today in the zoo and took some great pictures, but regrettably we could not go very closely to the cheetahblock, so i stood about 25 meters away from this cheeta, turned the digital zoom on (for the first time) and went to 7,7 digital zoom,

ok the legs dont look good at all but the rest of the body looks quite acceptable to me, what dou you think?

(from germany, so sorry for my english)



here a sample without digital zoom



http://www.flickr.com/photos/64419555@N00/

I don't see tthe need for digital zoom. You can take a picture using the maximum optical zoom and then use software interpolation which can be better than digital zoom. P.S. The second pic is nice
--
Canon A610
Skopje, Macedonia

Digital zoom basically just crops and enlarges a section of a regular zoom image. As vlatkovr says, you can do this better yourself on your computer.

... unless you don't have a computer and any kind of program for manipulating images.

Do you have any PC software recommendations in order to "digital zoom"?

Previously I tried several programs & several algorithms and I was able to match the digital zoom on my Canon A300, but I could not better it. So I figured Canon must me doing a pretty good job in this regard. But I have always heard that "zooming" on the PC is better.

Any suggestions would be appreciated.
Thanks in advance,
Mike

Your missing a point here.

The camera will (or should) be able to get a better picture using digital zoom then photoshop(etc) as it processes the raw file before JPG compression.

There was a test done here with a S2 that clearly shows much better definition with digital zoom then photoshop and optical zoom.

Other tests have shown the opposite, especially with the newer algorithms (bicubic smoother, bicubic sharper) in recent versions of PS/PE.

Duh! Good point -- never thought about that before.

So if your camera has a RAW mode, and you use it, you're probably marginally better advised not to use digital zoom and crop the image in the computer, because you can fine-tune the crop at post-processing time. (Premise: the more you can delay choices that affect the image until later -- like white balance and fine-tuning exposure -- the better.)

Otherwise, use digital zoom when really needed, recognizing you'll end up with a pretty low resolution image.

Thanks.

I just ran a test with the A610 at 140 mm (full tele) and an effective 560 mm with digital zoom. Noise reduced both the 140 mm image and the digital zoom image with NeatImage, then cropped the middle piece out of the full tele version in Photoshop and upsized it to the same pixel size as the digital zoom image using Photoshop's bicubic smoother interpolation -- which is the appropriate method when you're increasing resolution. (Otherwise, you'd be enlarging the jaggies.)

Neither the digital zoom nor the PS crop version was very appealing to the eye -- my eye, anyway. Maybe they could be sharpened up a bit, but actually images like this don't respond very well to sharpening since they have very mushy edges to begin with. If you had the full-size images you'd see that the PS crop looks ever so marginally sharper. The difference is virtually indistinguishable when reduced to a web-able JPG, so I didn't bother to post them for your viewing displeasure.

The digital zoom JPG is slightly larger than the Photoshop crop JPG, suggesting that it has more small things in it. Small things could be detail or they could be noise. In this instance, I think they're noise, not detail. The PS crop was noise-reduced before cropping; it cleaned up as well as NeatImage is able. The digital zoom image didn't clean up well. I think the NeatImage profiles don't really apply to the digital zoom image, since the sensor noise has already been resized in the camera when the image is upsampled, and we don't have a profile for that (bigger lumps of noise). The comparison might've been more favorable for the digital zoom if I'd shot at ISO 50 rather than 100, but I didn't, and that's that.

The pro-digital zoom argument is based on upsizing the RAW version in the camera before converting it to JPG. Given this test, and another like it I did a few days ago, I'm not sold on digital zoom, that argument notwithstanding -- unless you just lack the means, motive, and opportunity to crop your images afterwards.