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I agree

M31 Asking for a friend...

TimothyTim
24 Jan, 2020 04:54
Hello;

Recently I decided to compile multiple acquisitions I had last year of M31 through multiple scopes and drizzle them. I definitely like the result I came out with.

I’m curious though how far is this image in quality from being considered for IOTD. Please don’t misconstrued this post as me trying to get a nudge for consideration. I’m simply curious to gauge my process.

https://www.astrobin.com/995tle/D/

Thank you in advance!
Bella123
24 Jan, 2020 05:04
I think it is excellent! You can even see the core of ngc 205, very rarely see that! It would be nice to see some ha mixed in to accentuate the nebulosity in the spiral arms, and decrease the brightness of the core a bit, but it is still a fantastic image much better than one I ever did!
Edited 24 Jan, 2020 05:10
TimothyTim
24 Jan, 2020 05:12
Thanks Shawn! I thought about adding Ha maybe I will later. The core is a bit of a personal preference I could’ve nuked it but I feel the ones that do feel a bit unnatural… personal preference I guess!
H.Alfa
17 Feb, 2020 10:02
Hi. If you are looking for suggestions, you have a very good data but it is overstretched in L. I mean, it has so much Luminance that it has eaten the color saturation. Bigger stars suffers from overstretching also.
TimothyTim
17 Feb, 2020 10:12
Alberto Ibañez
Hi. If you are looking for suggestions, you have a very good data but it is overstretched in L. I mean, it has so much Luminance that it has eaten the color saturation. Bigger stars suffers from overstretching also.

Thanks
Chris-PA
17 Feb, 2020 16:29
I like it a lot - the detail in the dust lanes and noise level are top notch. I think Ha would be really beneficial here if you can add it. The colors are a little on the pale side and the background looks just a tad too dark for my tastes (but I think most people would say mine tend to be too bright). The core and a few stars are also saturated (I have a nifty monitor that will show me saturated spots if I look at it from a steep angle). Do you do any star reduction techniques? Overall though: It's excellent.

As far as how far away this is from an IOTD: I can't really say as I'm not a judge and never have been, but I think for popular targets like M31, you'd have to show something 'new' or never before seen or just really blow it out of the park with an image so perfect that there's basically no room for improvement. This image is excellent, but good M31s are a dime a dozen.
TimothyTim
17 Feb, 2020 16:38
Thanks Chris for your time. Yes I think Ha would definitely help but it’s too late to add now and will have to wait till next year on that. Regarding the stars I did use a couple of star reductions runs on this to my taste with star masked morpho and MMT, I’ll try playing with the stars a bit more and see about less noise reduction touch smile

Regarding the core it was entirely a personal preference. I did reduce the core glow but I don’t like pictures where the core is completely destroyed after all its a super massive blackhole that deserves respect!
ODRedwine
17 Feb, 2020 19:02
First let me stress that this is a fantastic image! I would be very proud of if I had taken.   Now, you asked for criticism so here goes, put your thick skin on.

1. Coma,  not bad but it is present in the image mainly at the top. Might be a small collimation problem.
2.  Some diamond shaped stars at the bottom, perhaps from coma or a processing artifact
3. Very slight star ellipticity  running between 5 and 11 o'clock ( about 25 degrees). Master that guidance!
4. Framing,  too tight!
5. very faint halos around bright stars.  Perhaps this could be removed with a tight star mask, but it is something we SCT users live with.
6. Target choice. The IOTD is usually a  flawless photo of some rarely shot, difficult target.

Micro criticism off:

Again this is a great image and I'm sure you will get lots of great comments on the beauty that you have created; however that won't help you get IOTD.  You obviously have great skills.  Good luck on your quest, but don't forget to enjoy the journey.

PS
Taking a closer look at the ellipticty it seems to vary from top to bottom.  Try to select your guide star as close as possible to the center of your frame, otherwise a slight polar misalignment can show up as field rotation. An arcsecond is all it takes to make the stars slightly elliptical.
Edited 17 Feb, 2020 19:11
TimothyTim
17 Feb, 2020 19:17
David Redwine
First let me stress that this is a fantastic image! I would be very proud of if I had taken.   Now, you asked for criticism so here goes, put your thick skin on.1. Coma,  not bad but it is present in the image mainly at the top. Might be a small collimation problem.
2.  Some diamond shaped stars at the bottom, perhaps from coma or a processing artifact
3. Very slight star ellipticity  running between 5 and 11 o'clock ( about 25 degrees). Master that guidance!
4. Framing,  too tight!
5. very faint halos around bright stars.  Perhaps this could be removed with a tight star mask, but it is something we SCT users live with.
6. Target choice. The IOTD is usually a  flawless photo of some rarely shot, difficult target.

Micro criticism off:

Again this is a great image and I'm sure you will get lots of great comments on the beauty that you have created; however that won't help you get IOTD.  You obviously have great skills.  Good luck on your quest, but don't forget to enjoy the journey.

PS
Taking a closer look at the ellipticty it seems to vary from top to bottom.  Try to select your guide star as close as possible to the center of your frame, otherwise a slight polar misalignment can show up as field rotation. An arcsecond is all it takes to make the stars slightly elliptical.

The coma problem was because I combined data from my ES80 with the Hyperstar. I had some major coma issues with the ES80 and have since replaced it with an ESprit 100. That is kinda the reason why I framed it so close to decrease the exposure for the terrible coma I have caused by the tilt.

Again, thank you so much for your input!
 
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