andrew s

I am not sure you need them for imaging. You should have flats for each angle you use! I have one for my spectroscopy to avoid the target spectra overlapping an other or stars in the field. As my kit is remote it's a necessary bit of kit. Regards Andrew

Try this How they work Regards Andrew

Interestingly Starlight Xpress did experiment with the clocking on their CSX 304 CMOS camera to reduce amp glow. Regards Andrew

Certainly you can do that. You can also very easily check your camera to see if it meets specification. Gain, dark current, linearity, well depth, cooling capacity. When comparing images there are many factors in play. Not least of which are optics, sky conditions and processing skills. Personally given what can now be done in software post processing it's not clear to me how you would isolate the camera from all else that is in play. However, I realise I am in a minority on this issue in astronomy but not it seems with general photography where they seem to value measurement as well as subjective comparisons. Regards Andrew

Unfortunately, we don't have an astronomy press that quantitatively compares equipment. While with optics this is difficult with CCD or CMOS cameras the basics can be easily measured. In fact anyone set up to do astro photography can do it. It is also a fact of life few if any SGLers will have access to multiple equipment with, in this case, the same camera chips. That's why we have not been able to help. I did point out the only comparison I new about which showed camera can differ but it was not the chip you were interested in. Regards Andrew

Nice pairing. Glad you like the new filter. Regards Andrew

Hi @tooth_dr sorry don't know what more to suggest. Just looking isn't giving me any inspiration. Sorry. Regards Andrew

3) looks fine. I would expect 2) to be wrong if the bias has not been subtracted . Check the back ground in your image before and after bias subtraction just to see if it was done correctly. Not sure what else to suggest but you original image does not obviously show the vignetting your flat does. Can you check this ? Final thoughts, I assume they were taken at the same temperature? Is there a reason you don't use darks and flat darks. . Regards Andrew

No, apply the master flat to a single flat frame. Regards Andrew

Assuming the images were correctly calibrated (dark, bias etc.) then if the flat does not correct correctly it is probably due to one or more of: light leakage on darks, mismatch in light path illumination between target and flat or something changed e.g. filter or focus. Just to check the process and software apply the master flat to a single flat calibrated with bark or bias to see if it works on that. Regards Andrew

Still very much a beginner at visual. I am still trying to learn how to observe rather than just have a quick look. The scope seems fine though due to the weather and personal circumstances have not been out that much. I am the limit not the scope. Sorry I can't be more help full. Regards Andrew

I tend to give my old kit away so the oldest gear I have are my 69 yr old eyes. 👀 Regards Andrew

@ollypenrice is spot on "useful" meant getting if published in the BAA journal or equivalent. For a hobby there are not limits but a scope or binoculars with an aperture less than the size of your iris might be of limited use. But wait, pin hole cameras have there uses! Regards Andrew

During winter, I.e. now we are GMT = 0 . Regards Andrew

Nice sequence of images. Regards Andrew

First image of volcano on Io. Regards Andrew

Very subtle. Regards Andrew

Amazing drawing. Regards Andrew

Always! Regards Andrew

Unfortunately, I have no experience of your kit or software but after a significant error I would "home" my mount before proceeding. Maybe you can do the equivalent, home, sync etc. Regards Andrew

When very close to the meridian a small amount of cone error could make the mount point to the wrong side of the meridian compared to its "side of mount". Not sure if this helps but just a thought. Regards Andrew PS 3 to 4 deg would be a very large cone error though.

Impressed with that, especially given your location. Regards Andrew

Nice to see you back Dave. Regards Andrew

Bernard Schmidt blew off a hand but he still managed to make his famous optics. It's amazing what's possible when you have the necessary drive. Regards Andrew

I found a spent rocket on the roof of my ROR obs one 6th Nov. I never try observing on the 5th. Regards Andrew