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Jupiter is a blown-out, white, disk

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#1 CharlesW

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Posted 21 November 2012 - 11:27 AM

Good morning folks, last night I spent some time trying to image Jupiter for the first time and all I could get is what looked like an extremely over-exposed, white disk. Here's the equipment:
Celestron 8" CPC
Canon 50d
Not using a Barlow
Backyard EOS
Registax

I was using the planetary mode in EOS to write video, about 400 frames. I tried iso settings from 200 to 1600. Even just looking at it in EOS it was just a white ball with none of the detail I could see using an eyepiece. Focus was good. No amount of histogram stretching was helping.

Do I need a filter to knock the brightness down? I can't imagine that dropping iso to 100 is going to help much. Or, is there something else I'm doing wrong?

#2 Tapio

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Posted 21 November 2012 - 11:47 AM

It's best to use lowest ISO (100?) with planets.
Don't know if you can adjust exposure with 50D/video but if you can then you should do that.
Magick Lantern can do this but this is another matter and maybe you should try something else first.
http://magiclantern....n_Firmware_Wiki

#3 ToxMan

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Posted 21 November 2012 - 11:55 AM

Use a barlow, don't stretch histogram. Generally, I don't use a DSLR to get video. But, on my Olympus, I can adjust my shutter speed for video mode and keep image from being "over-exposed." And, my camera only has 2 frame rates for video mode. Jerry Lodriguss and some others have tutorials for imaging with a DSLR, whether it is planets or deep sky.

#4 skywatch

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Posted 21 November 2012 - 12:01 PM

You probably need to set the liveview exposure to manual (simulated exposure) rather than automatic. Not sure where that is on the 50d.

-Rolf

#5 RedLionNJ

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Posted 21 November 2012 - 01:36 PM

I see no mention of exposure length. What are you using? I typically use somewhere between 1/10 and 1/50 of a second, depending on the transparency and optical train.

Grant






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