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Why are there subspecies?
Rasmus, I'd make three points here. First, I was not writing for clarity, not detail. So yes, the minutiae does become a bit more complex! Secondly, I don't see how you can write that "numerous subspecies come into contact, and if there was little or no intergradation, they would be species...- Tannin
- Post #27
- Forum: Bird Taxonomy and Nomenclature
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Why are there subspecies?
Richard, Pariah gave you a pretty good answer right away, but let's see if I can't boil it down to something short and simple. H sapiens is generally considered to be monotypic because it is monotypic. Determination of "species" and "subspecies" has nothing to do with the size or number of...- Tannin
- Post #24
- Forum: Bird Taxonomy and Nomenclature
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A strange move by Canon
Now you raise an interesting point, Thomas! I've never owned a 350D (played with a friend's one a bit though) but I have owned a 400D, which by rights ought to be the same as the 40D (of which I still own two). But I don't think the 400D does as good a job as the 40Ds. (Or hte 20D for that... -
A strange move by Canon
Compared to what? A 300D? Any image quality improvement the 40D provided over the 20D/30D was marginal. Not much difference in the AF system, inferior colour, not a lot in it for noise, but about 1/3rd to 2/3rds of a stop behind the 20D. All in all, a lack-lustre camera, considering the superb... -
New 20D owner
Wow! That's a pretty steep price for an ancient camera. :( Maybe if you got it with some bells and whistles. But no matter: the 20D is a superb camera, clearly the best camera on the market in its day (excluding mega-expensive exotica, naturally) and still more tan capable of delivering... -
A strange move by Canon
This is a fundamental misunderstanding of the way diffraction applies to sensors. Diffraction has got nothing to do with sensors. It is purely and entirely a lens issue. 100%. The only difference is that higher resolution sensors are able to record the light coming through the lens more... -
50d BIF 9 point focus V centre point focus
Centre point is best for BIF. The focus assist points on the 1 Series are excellent, but the 50D doesn't have these. Try to keep the bird as centred as you can, and stop down a bit so that DOF will help you out a bit. -
A strange move by Canon
Not remotely strange: the Canon entry-level new models have always been pushed through pretty quickly, generally once a year. The 500D is a year newer than the 450D which was a year newer than the 400D. Totally standard release schedule. Nor is it at all strange to see the latest xxxD come... -
1D Mk111 with 100-400 plus TC-will it AF?
AF with a Canon 1.4 TC and a 100-400 on a 1D III is centre point only and quite slow, but accurate and perfectly usable. It is noticably faster than using a 2X Canon converter on a 500/4. I tend to avoid the combination where I can, but it does work OK. Bit of a waste of a 1D III though. You'd... -
Sensor cleaning question
Auto-cleaning is absolutely worth having. It works, and works brilliantly. I own or have owned 400D, two 40Ds, 50D and 1D III, and have never had to manually clean te sensor on any of them, while my two 20Ds (which don't have self-cleaning) are constant dust bunny warrens. I would not even... -
Tamron 200-500mm vs. Sigma 50-500mm DG
Sorry Alan, but the description I gave above is quite correct (though lacking some detail). I'm afraid you have got completely the wrong end of the stick here. The difference you are observing between two different "500mm" lenses, assuming that you are measuring then both under the same...- Tannin
- Post #31
- Forum: Sigma & Other Third Party Lenses
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Tamron 200-500mm vs. Sigma 50-500mm DG
Oh dear, ancient thread, but there doesn't seem to be a sensible answer to the magnification question, so we had better have one. Max magnification is simply what happens when you combine focal length and minimum focus distance. You get greater magnification if you increase the focal length...- Tannin
- Post #29
- Forum: Sigma & Other Third Party Lenses
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Which lens to go alongside my 500mm?
I have the 500/4 (1D III) and the 100-400 (50D). The 100-400 is certainly useful sometimes, but not all that often. It's a very useful range of focal lengths, but is let down by (more than any other factor) speed, in both senses: I often miss having f/4; and it is much slower to focus. For... -
Since I have started using the 1.4x my pictures have suffered, advice please
Don't use the converter. If you want to use a teleconverter, buy a lens that is designed for that task - any of the Canon f/4 or f/2.8 primes. But even with those, you still get the best results shooting bare-lens. The 100-400 isn't designed for use with a converter. -
Metering mode query for 40D camera.
It doesn't really matter what metering mode you use, so long as you pick one and stick to it. Get to know what to expect from that mode, and then you are in a position to accurately guess the correct amount more often than not. Spot: very accurate provided you have the spot where you think you... -
40D image quality
I second Adey's comments, apart from the "more intense colours" part. At least so far as I can tell, that is a side-effect of the 40D tending to under-expose a little compared to the 20D.If you bring both shots back to the same overall brightness (add a little to the 40D or darken the 20D a... -
50D or 40D?
Whooah there Roy! Yes, by all means compare 100% crops between two different cameras with the same sensor size and the same pixel density. That is a perfectly reasonable thing to do. It probably won't match the actual resize you do when you publish the image, but it does the same thing to both... -
500 f4 - so near yet so far...
You have to wonder if your retailer is shipping you the lenses someone else rejected already. Two duff ones in a row - that is not what you expect with any Canon product, never mind their flagship super-telephoto lenses. I've bought ... er .. I think it's 11 Canon lenses now and never had the... -
upgrade from 350D....40D or 50D?
Spot on, Frank. I'll take that bet ...... but only after we carefully define what we mean by "about". With the same lens and same everything else - including the same cropping to show the same amount of the bird - images from 20D, 40D, 50D, and 1D III are indeed about the same. None of them... -
upgrade from 350D....40D or 50D?
Sorry Peter, I should have expressed that more clearly. Take the same picture of the same bird with the same lens (poor little thing must be really wishing we would pull out those nails holding it on the perch by now) with a 40D and a 50D. I did a fairly lengthy post on exactly this the... -
upgrade from 350D....40D or 50D?
Very, very different things! You don't actually gain all that much extra reach with a 500/4 as compared with a 400. A bit, yes, but nowhere near enough to justify the expense (huge) or the weight (massive). Of course, you can add a 1.4 converter for 700mm f/5.6, and that becomes significant... -
upgrade from 350D....40D or 50D?
Interesting experiences there, Roy. "Interesting" because my experimentation with a very similar pair of cameras leads to a very different conclusion! I had two 20Ds, which were pretty much indistinguishable quality-wise. Naturally, I had a favourite one out of the two, but I don't try to fool... -
upgrade from 350D....40D or 50D?
If you compare correctly - i.e., compare finished images - not true. 50D wins comfortably. If you do silly things like compare 100% crops, you may well get this result, but it's meaningless. You need to compare two things by reproducing them the same way, at the same size. If you do this, the... -
upgrade from 350D....40D or 50D?
Hi Roy, Reach is the amount of detail you can resolve from a distant small object (such as a bird). The primary determinant of reach is pixel density. (Assuming, of course, that we hold other factors equal: we use the same lens for example, and shoot under similar lighting conditions.) To a... -
upgrade from 350D....40D or 50D?
No argument with the Roy and John about the merits of the Mark III, if you incline towards the action side of bird photography, it's the best there is. But that's not your style, Peter, and with a 1D III you don't have nearly the reach you do with a 50D. Shooting the same bird from the same...