CompuServe Thread

#lens settings

2 messages in this thread
#3871From: Noah KennedyOct 3, 1991 11:32 PM
On a couple of recent projects that involved mapping 3DS images to 35 mm photography, I noticed that when we matched/scaled one to the other that the lens settings in 3DS did not correspond to those with which the photograph was taken. This differs from, say AutoCAD DVIEW, where the correspondence has always been very exact. It is very possible that I "forced" a fit with the wrong lens setting, but I consistently (say over six separate shots) get something like one stock lens setting off: eg a 35mm(3ds) matches a 28mm(photo); a 50mm(3ds) matches a 35mm(photo); etc. I also noticed that your FOV angles deviated from what I had been using in the past for one lens setting by a few degrees. FOV was explained to me as the angular measurement from one corner of the rectangular field to the opposite/diagonal corner. Is that correct what 3DS means? –Noah
#3878From: Yost GroupOct 4, 1991 1:00 AM
I'm sure that the lens scaling in 3DS 1.0 is wrong. We're going to be changing it in 2.0 to be consistent with the way Ashade does it. You're correct about what 3DS means by FOV… it's the distance from the upper-left to lower-right corner. We got our original numbers from a Canon lens chart, but it turns out that the chart we were using was either wrong or we interpreted it wrong. Whichever… it's fixed in 2.0. – G