David VanHorn wrote: > On 9/29/06, Alan B. Pearce wrote: > >>> I Bet you would want to be that close to a launch!!!! >>> > > > > Telephoto lenses make everything look much closer to each other than it > really is. > "foreshortening" > I did the math.... As far as I can tell the Soyuz TPM-9 was about 200feet tall (this was really hard information to find, and is the sum of the lengths of the various rocket stages I could find... Stage 1, 2, 3 are 64, 91, and 22 feet respectively. The command module is 7 meters, or 22 feet as well), and I'll guess that the person in the photo is 6feet tall. This creates a size/height ratio of about 34:1. Using Gimp, I get the soyuz rocket to be about 2180 pixels, and the person to be about 230 pixels, giving a ratio of about 9.5:1 Based on this, the person is about 1/3rd the way between the photogropher, and the rocket. Given that the the lens used was a 300mm f2.8 lens, (I presume this one... http://nikonimaging.com/global/products/lens/af/telephoto/af-s_vr_300mmf_28g_if/index.htm ) and the D2X camera has a DX sensor (1.5 crop factor), the field-of-view will be 5.3degrees. Again, back to the picture, the rocket is 200' and 2180 pixels. The full frame is 3216 pixels (the "Medium" image size from the D2X sensor). Thus, the full-frame height at the distance of the rocket from the camera is about 200 x (3216/2180) = 295 feet. Using trig, this gives the distance to the rocket as about..... tan 5.3 = 295/x thus x = 295/(tan 5.3) thus the distance to the rocket is about 3200 feet, or 970 meters. Doing the same math on the person, instead of the rocket, the person would be: 6' and 230 pixels in a frame of 3216 pixels means the full frame height at the distance of the man must be about 84', which, at the field-of-view of 5.3deg is 905 feet from the camera... or 2300 feet from the rocket, or 700 meters.... 700 meters is far more than the image depicts, but it is probably a lot more accurate.... especially when taken in combination with the following video's I saw earlier that show that the launch pad is in a slight depression, and the person in the photo must be near the crest of the edge of the "bowl". Still, imagine being 700m from the launch of a rocket like that.... very cool, but the photo is even cooler... ;-) Rolf -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist