rkg

Thanks for the comments - I've actually got better work to rotate into my website, but don't have the time right now. On the lens distortion - you can go to the following test site and pretty much figure out where the lens distortion is minimized for a particular zoom: http://www.photozone.de/8Reviews/index.html Thre really isn't a single focal length for all zoom lenses where they have minimum distortion. On the apeture setting, maximum 'sharpness' depends on your sensor resolution vs. the resolving power of the lens vs. diffraction effects. A lot of consumer lenses "peak out" in resolution around f/8, but again, it depends partially on what lens you're talking about , and partially on physics (you can't get around the rayleigh limit...). Again, you can check the above site or do your own resolution tests (google koren lens test) to objectively see where your lens/camera combination peaks out... The good things about these 1.6x crop cameras is that 1) they use the centers of lenses, where a lot of them are actually fairly good, and 2) you get a lot more depth of field, so you're not having to try and shoot stuff a f/16 to get it sharp top to bottom... On lenses, When I want the "best" picture I can get, I usually use a prime of some kind - there are a couple of issues with zooms - first is the distortion thing (there's only a small region where there's no distortion (and sometimes they distort badly across their entire range), resolution in general (these lenses are extremely complex, and you have issues with design and actually how they were assembled - its usually a good idea to test any zoom after buying it to see if there are any problems (the old "brick wall" test is fairly quick)). The second is a little issue called "transmissivity" that most manufacturers try and avoid talking about - a lot of these modern zoom lenses have so many elements that they actually lose an appreciable amount of light going through them, so you end up with a slower shutter speed for a given apeture for correct exposure. Primes tend to be simpler designs (so they get correctly manufactured most of the time), are distortion corrected, let through more light, and are (if its a good lens) capable of out-resolving your camera's sensor so everything looks sharp. On the "picture book pictures" - these were mostly done with medium/large format cameras in the past - and honestly, getting a overall sword picture that "looks like that" with anything less than a 12 MP or so camera is dicey - you can figure the number of pixels - the human eye can only resolve somewhere between 215 and 400 PPI depending on the contrast of the subject (which is why most cameras tend to put their "native resolution" at 240PPI - looks sharp for "general" photos). for example, taking a 20D's sensor size (3504x2336), going across the diagonal and dividing that by say 215PPI would only allow you to get an object what, 19.5" or so at a high resolution - same calculation with a 1DS MKII sensor gets you to 27.9" Fortunately, you can probably get away with slightly less resolution for most stuff. Take 180PPI - at that range, the numbers would go to ~23" for the 20D and ~33.3" for the 1DsMKII. Empirically, I've seen work done with a Canon 5D that is comparable to "those pictures", so you can probably go lower, but this gives you some idea of the tradeoffs. The second issue is that swords, particularily with the black backgrounds have incredibly high contrast, so you have issues with rendering them for print - You have to print at like 400DPI or more to make the aliasing "jaggies" small enough so they don't catch your eye. I'm still wrestling with whether this is a "real" problem or not (I'm thinking I can solving it by doing iterative resampling), but other people I've talked to are convinced it is, so... On the studio flash, its a pain because of trying to get the exposure right and observing what actually will end up being photographed (things seem to look different between what you see with the modeling lights on and when the flash itself fires) - but gives you a Very Fast effective shutter speed, so you don't have any of the issues with vibrations that you have when trying to use "hot lights" (which take a fairly long exposure, even with monster lights (a 1000W light in a big softbox isn't as bright as you'd think). I'm still using hot lights for this because I can see the "end product" in real time - speeds up things a lot, given how touchy lighting is on swords to make them look their best... Sorry for the diatribe... rkg (Richard George)

Leroy, The sigma 17-70 doesn't seem to be too bad a lens, as long as you aren't shooting it at or near 17mm, which shouldn't be that much of a problem, as you probably should be shooting with it at ~35mm to minimize the barrel distortion. As far as a recommendation goes, it kind of depends on what you are trying to capture. for closeups, I use either a 100mm macro or my Tamron 180mm macro (sharpest EF mount lens I've ever used), and actually for overalls I usually try and use a prime and shoot diagonally (50mm macro), though I've also had good luck doing this with a 17-40 f/4L as well. I'll also sometimes use a 24mm shift lens to get out of the picture and have no distortion, though most people can get away with just shooting off axis a little to accomplish this. Was your comment about tripod size because you are shooting down on the piece? if so, you may want to think about improving that setup as well so you don't have to use your lens at its shortest focal length - the simplest solution is to get a bigger tripod and a Bogen right angle tripod arm so you can hang the camera out over the piece more easily. I usually end up using a sandbag on the ground to tie the other end to as a counterbalance. If I recall correctly, the XTi doesn't have shutter lockup, which is a bummer as it helps a LOT when you're trying to get high resolution photos (the mirror slapping up makes stuff jump all over the place - which is bad because you are going to be shooting stopped down (which usually means slow shutter speed unless you're using studio flash or incredibly bright lights) to get enough depth of field). About the best you can do is get a matthews baby boa bag (or some sheet lead) and wrap it around the head or arm on the tripod to damp vibrations and use the timer or remote control to trigger the camera. Or you can go to a studio flash setup for illumination to get the shutter speed back up, but this is usually quite a pain (seems like the modeling lights don't quite show what you're going to see + its a pain to get the exposure right - even with a flash meter it takes some testing...). As an alternative, you can just use your existing tripod by using it closed as the boom and attach it to something that isn't going anywhere (ladders, sandbags, clamps, and rope can be your friend here). Good Luck on your endeavor... Best, rkg (Richard George) http://www.rkgphotos.com