M57 flat test

First, let me apologize to anyone who has been trying to observe in the Four Corners region. I am the one who got the new equipment and brought the clouds. (The new wedge for the 16 inch is installed.) In the mean time, with moon, vacations, rain, etc., I wasn't able to image anything for over a month! Probably the only clear time available for the last couple of weeks. There was a moon up when I took these, so that likely affected the result.

I was only able to do a "polaris" alignment this time, but was close enough to get going. My first goal with the new wedge was to see if no field de-rotator had any help with getting flatter backgrounds. And my quick answer appears to be yes. This is LRGB at 22:11:11:9 minutes (had to toss a strange mix of frames), spread over ~2.5 hours. The only processing was an "unsharp" on L and "logarithmasizing" as much as the slider would let me.

I hadn't intended to do any more with this, but since I think this is enough better than my earlier shots that I may have to re-visit and maybe add some Ha to get the halo.

Comments and suggestions always welcome. Thanks for looking.

Charlie

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Here is a stretch on the L channel to see the flatness. This was a T-shirt flat near dawn, but I don't know if it (the cloth) was uniformly stretched enough (see upper left area). I think I have gotten better on individual frames previously, but never this good on a combined set when the rotator was doing it's thing. I think I will leave the camera in this orientation for a while until I have chance to repeat the flats - maybe with a different cloth. (?) Ideas? Should this be lots better? Is this stretch like doing a flashlight-through-the-back test on a new mirror?

Charlie

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Hi Charlie,

Nice shot.

Are you getting "flatter" images because you can better match your sky flats to your images because you can take the sky flat with the exact orientation of the camera? I'm a bit confused because you said the only processing you did was to "stretch" and do a little unsharp mask.

Are you using a Pyxis for a de-rotator? I'm thinking of getting one ...

Nicely done Charles!
I can also see a nice galaxy on the bottom left hand of M57... cool! 8)