On 2014-01-02 [email protected] wrote: > I'm trying to do calibration of a fairly wide angle lens (14mm with a > 2.0 crop) and am finding it hard to get what appears to be even > illumination - I certainly don't have a light source that can apply an > even enough illumination to my ceiling.
It's easier to get the quality of illumination you need if you don't worry about getting too much intensity, and use a longish exposure. If I recall, I ended up holding my camera up near the ceiling to reduce the area (and variation in brightness) I was "photographing". > Does this mean that my diffusion material isn't diffusy enough (I have > tried a white plastic trash bag)? In that case, would a Roscolux > diffision gel be a reasonable thing to buy if I'm done trying to come > up with a solution from household materials? I wouldn't say so, based on my experience. While it diffuses light nicely, it was a little awkward to work with, not having enough mass of it's own to hold it tight against the rim via gravity alone. I think if I were going to do it again, I would probably try some other things first... maybe a piece of white adhesive vinyl, of the sort used for lining kitchen drawers, etc... actually, maybe I'll try a few things tonight and report on the results... for science. ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
