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Andy Taylor
Twisted, but in a Good Way

Reged: 09/24/08

Loc: Epsom - UK
Re: Fail - yet again... new [Re: ToxMan]
      #5666890 - 02/07/13 11:18 AM


Very interesting, Andy. I have often wondered if filters get slightly tilted. Or, the possible effects if filters are stacked in the optical train. I've considered light reflecting off filter and CCD for bright objects, like the moon or sun.

Since you work with video and the optics, I wonder if you would know why I got these patterns in my images taken with an older planetary camera, DMK31. It seemed to occur when pushing the image size with C8 + 2x barlow + FW + camera, adding extension tubes to get to f23. As I increased image size and gain to make up for dimming, the pattern appeared. TIS reps said it is Moire. But, I don't know how I can get Moire.

Here is an example:

Heck - my camera experience is more with good 'ol 35mm movie cameras, although I am being dragged kicking and screaming into the digital world.

The new cameras use a low pass filter which causes it's own optical can 'o worms.

I have no knowledge of the DMK31 but I would imagine that the fringing could be a camera artifact or even maybe an interference pattern from the CCD and the reflection from a slightly skewed filter.

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Carpal Tunnel

Reged: 01/23/11

Loc: Tucson, Arizona, USA
Re: Fail - yet again... [Re: Andy Taylor]
      #5666981 - 02/07/13 12:11 PM

Thanks, Andy. Honestly, it has been a dilemma. Bottom line, I don't try to image that way. Every setup has a sweet spot and when conditions are right, the real fun begins. Enjoyed your thread. My wife told me I'm not as smart as I think...she got a kick out of your thread, too.

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