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Post by virgo on Mar 19, 2012 19:43:04 GMT
Another image Attachments:
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Post by virgo on Mar 25, 2012 23:59:40 GMT
The 25th March was a wonderfully mild and clear night, but seeing as usual was poor Attachments:
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Post by brianb on Mar 26, 2012 8:50:45 GMT
I think you have a focusing issue! Managed to get some reasonably sharp images last night despite poor seeing, rotten transparency and significant wind vibration (which prevented me from using my C11). Here's the best: 2012 March 25, 2030 UT. William Optics FLT 110, 4x Powermate, Astronomik colour seperation filters, Imaging Source DMK21. Red channel used for luminance. Mars being tiny, this is a 200% resize ....
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Post by virgo on Mar 26, 2012 10:14:34 GMT
Could be , Brian. I suspect a nearby oil fired boiler might have had some influence. Focus is always a problem as the image continually changes. Virgo
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Post by brianb on Mar 26, 2012 11:09:31 GMT
Yeah, focusing is never easy but time spent trying to get it right is rarely wasted! Here's my composite from yesterday. Even the blue image has detail in it! Don't know what went wrong with the IR, it's usually the best ... I usually take at least two sequences as seeing does vary
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Post by virgo on Mar 26, 2012 15:13:58 GMT
Hello Brian, Considering the 13 odd arc secs of disk remarkably good images. I used a standard Philips webcam which does not allow any experimenting. Wind vibratation is always a serious problem and can smear out detail. The answer of course Brian is to buy yourself one of those nice observatories that Andy is selling!
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Post by brianb on Mar 26, 2012 18:00:51 GMT
Thanks ... not bad for 4.3 inches ... the good news is that the haze & high cloud has cleared, the seeing is a bit steadier & the CPC 1100 is outside cooling off ...
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Post by virgo on Mar 27, 2012 10:35:16 GMT
Hi Brian, Last night was fairly average seeing wise. Mars, still bright allowed some imaging, but sky conditions severely limited resolution despite careful focusing. Attachments:
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Post by brianb on Mar 27, 2012 15:16:03 GMT
March 26th: Seeing did deteriorate but it was still better than I've had for a while. Two sequences shot. First set: I think the second set might be better once I've solved a "technical problem" which is delaying processing. BTW I know what the issue with the IR was on the previous set: infra red has a focus shift on the "apochromatic" fluorite triplet refractor & I forgot to refocus :blush:
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Post by virgo on Mar 27, 2012 15:50:56 GMT
Brian, You'll be putting Hubble out of business!
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Post by brianb on Mar 27, 2012 19:58:09 GMT
A few hints for focusing: turn the gain on the camera way up and turn the gamma down or contrast up (depending on the control you have). Reduce the exposure to help freeze the seeing ... the image will be unacceptably noisy but it's easier to focus that way. Set the gain, gamma / contrast & exposure back to sane values before shooting the video.
A one shot colour camera is easier to handle but, as you say, less flexible - mostly because you can't shoot in UV or far into the IR at all.
If you're at the LNDC event on Friday I can show you the videos the shots above were made from. I think you might be surprised how unsteady the seeing was for me.
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Post by virgo on Mar 28, 2012 0:56:51 GMT
Ok Brian, Thanks for the tip. took this at 21.40 many thanks Attachments:
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Post by brianb on Mar 28, 2012 3:38:43 GMT
That's an improvement. Starting to look a bit more like mine do before I learned some processing tips. Registax? There are loads of options and most of them make a difference, but the critical one is selecting a good reference frame before aligning: it usually takes me three of four goes. Try shooting with more contrast (or lower gamma) a contrasty image is easier to align & you can flatten it a bit in post production if necessary. Here's the delayed set. This would have been better than the previous set from Monday night but the blue channel was poor 8-( A bit better with the colour balance I think. Perhaps the bad blue channel was an indication of worsening seeing which was setting in, I tried to capture more sets at intervals but the seeing was rubbish. BTW I've modified the captions on the earlier set, corrected an error in calculating the central meridian. Didn't bother with Mars on Tuesday (27th), I was exhausted enough to have to sleep 8-/
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Post by virgo on Mar 28, 2012 11:54:13 GMT
Hello Brian, some more fiddling with Registax. Which version do you use? Attachments:
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Post by brianb on Mar 28, 2012 12:46:54 GMT
Still on v5. Haven't found any reason to upgrade. My lunar & solar stuff is done using Avistack which is significantly slower but works better (for me) for surfaces, it's supposed to do planets as well but I haven't found the knack 8-/
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