Quote:
Originally Posted by Andrew C
Hi Jeanette,
For future reference in case I get into video imaging, when you image using Gstar ex with short integration times like 2 seconds or less, are you using a tracking alt az mount, or is there sufficient tolerance in the short times for a small amount of movement in the position of the objects? Also what sized scope aperture are you using?
Also, Peter,
Could you explain which parameter in the Sony specs for the CCD sensors quoted spells out the sensitivity?
Thanks, Andrew
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Andrew, others may offer more detailed responses but from my understanding of the chips sensitivity is its Quantum efficiency in turning light into electrons???? please correct me if I am wrong.
When you look down the sony sheets about half way on each of their chips you will find the sensitivity sheet and the unit of measurment is mV. The 429 chip has alot higher reading in mV so I assume its more sensitive.
The other question you have I can answer, I can use my ALT/Az LX200 scope with the Mallincam set upto 28 seconds intergration with no field rotation showing anywhere in the sky. When I jump upto 56 second intergration I can then start getting a little rotation in my images if the scope is pointed up high near zenith but none shows down 60 degrees or lower.
If you have a good Alt/AZ mount you can use these video systems for imaging.
With the G-star users capture lots of 2.5 second intergrations and stack them using RGB filters to get colour shots which gives the same level of detail as longer exposures and as JJJ says you use dark frames to get rid of noise. This works great.
The Mallincam is aimed more for instant gratification and visual use as it has longer exposures with boosted gain and cooling to get the most out of its less sensitive colour chip.
Different cameras for different uses.
You can use these video systems at around 2 seconds intergration with a dob but unless you have the worlds best hand control you will get streaking across the screen.
You do need at least ALT/AZ tracking otherwise it will become a real pain.
Some people get fantastic results using video and round table platforms with their dobs.
Regards Matt.