Whether cropping is acceptable or not really depends on the final use of the image, does it not? I would submit that if the resultant image is an 8x10 print (or smaller)or a 300KB web image then extreme cropping can not be seen.

regards - tom

<b>300mm or 400mm? I haven't made an actual comparison of image sizes using both lengths but can't be a huge difference</b>

Proportional to the squares, so 16:9 or almost 2x ... but as some have pointed out, in brushy areas 300 is often enough, and remember that on the 1.6x crop d-SLRs the field-of-view of a 300 mm is equivalent to 480 mm in full-frame or 35 mm cameras ...

You asked for our experiences, Tom. You got them.

John

bump

I think this sidebar on crop is interesteing. Still, I have always understood that the &quot;bottom line&quot; went to Pixel Density&quot;. In other words, the number of photosites per unit area. One could make an analogy to film, i.e., fine grain is to resolution as higher pixel density is to resolution. So for example, a 21 megapixel sensor would provide an image that was capable of being croped far more severely than a 10 or 16 megapixel image. In a sense, you would be doing your own croping later in photoshop. I have seen some reports of how the megapixel differences between crop and no crop sensors translate into resolution, but I'm not sure I beleive the calculation. Thoughts?
Regards-Chuck

Chuck, I will give you my view on the question you just posed. I believe that the photosite density on pretty much every recent-model DSLR is so high that the limiting factor on cropping will be the lens, not the pixel density. The Canon Digital Rebel XTi and 40D have 10.1 megapixels on a 1.6x crop sensor, the Nikon D80 and D40X the same pixel count on a 1.5x sensor. The 1DIII has more pixels but a larger (1.3x) sensor. And so on.

At these densities, I believe cropping is far more likely to be limited either by less than absolutely perfect shooting (i.e., a tiny amount of motion blur or camera shake not visible in an uncropped image) or by the inherent ability of the lens to make a sharp image down to 100% on a pixel-dense sensor. I really do wonder what lens will withstand significant cropping on the new 1DsIII, and other previews of that camera I have read express the same question.

So, overall, I think the issue of pixel density may have been valid when DSLRs had lower pixel counts, but now I think they all have enough resolution to exhaust the limits of pretty much any lens.

That's just my two cents.

Chris
www.pbase.com/cwillis

I was in the same boat as you. I ended up buying he Nikon D40X with the kit lens 18-55 and also the 70-300mm with IS. The Nikon 70-300 IS received excellent reviews. I think the Canon is comparable. I also am taking my point and shoot as a back up.

I just used the Nikon 70-300 VR on safari and it is an excellent lens. Used it for 90% of my safari photos (on D200). The other 10% I used the 18-200 on a D40X. You've got this range covered. I never felt a need for anything longer than 300mm except for an occasional birdie.

regards - tom

jit,
I can't tell from you post above where in Africa you will be on safari. In East Africa you can always use more lens while in Botswana (and perhaps Zambia) you need less. Why is this? Are the animals bigger in Southern Africa? No, it's just that you are more likely to go &quot;off road&quot; and so be closer to your subjects. No kidding, I had heard that was the case but I seldom even put my 1.4X TC on my 300mm 2.8 lens. In fact, the next time I go to Bots (next summer) I'll be bringing along a 70-200mm 2.8 L IS Canon lens instead of my trusty 100-400mm lens. In Tanzania, it a different story. In East Africa you are more limited in not driving off into the bush but the terrain is different as well. Wide open grasslands rather than mopani brush require longer lenses. I would try to build a flexible kit if you intend on repeat safaris. Even non birders become interested in Africas diverse bird species. Much of lens choice should depend on what you are interested in (birds vs mammals) and where in Africa you are going. That accounts for the wide diversity of opinion on the best lens choice.
Regards-Chuck

Well said Chuck.

regards - tom

Hi Chuck, you make a really good point! We will be mostly gaming in East Africa and visiting the gorillas in Rwanda! I'm proud to say we are the owners of a Canon 30D : )