My M57 - beginner

[kirkster501]

What do you reckon chaps? 4 x 2min Lights, 10 x 2 min Darks, BIAS frames. No flats (what are they?).....

No guiding. This photo at Prime focus on a ED80 on my unmodded 1100d. No field falttener or any of that malarkey. M57 was near the zenith.

Not really sure what I am doing with curves and levels - screen capture here. Just followed on line tutorials and Steve book. Wish I could get the background darker.

Advice and guidance welcomed ! Stars near corners losing their roundness me thinks....!

Regards, Steve

[Chris]

Thats a good start, you can just crop out the eggy stars with the cropping tool which will also make the apparent size of M57 larger:)

[NickK]

I think you're on your way.. start with being able to take a good set of lights, repeating the next night for example.. then move onto adding darks and then after that start using flats.

Additional lights will help noise reduction, allow you to enhance image resolution if you desire. The flats will be come more important when you get into perfecting taking images.

A very good start! (and every APer knows a start means.. adding each year )

[Ags]

Looking good! I notice your curve is a bit odd though - it doesn't go down to zero at the left. That would be one reason why your background is not as black as you want - but the sky rarely is truly black.

[kirkster501]

Thank you guys. Yes, getting the principles right - that's the name of the game.

Here is one I did of M13 the same night. * x 2 mins in this case. But a little "noisy" I feel that spoils it. Anyway, early days...!

[VigdisVZ]

Good result and encouraging for beginners like me who is about to start doing unguideds!

[kirkster501]

Trust me Carl - I am 100% utterly a newbie at AP ! It is great fun, Just wish the weather was better in the UK and I would be at this for hours a night every night -I just love it Incredible sense of achievement, even for rough pics like these.

[Stargazer33]

You have a couple of really nice images there! Well done. I hope I can achieve something that good when I finally get around to DSO imaging. I'm still very much learning planitary stuff at the moment - when I get a clear night, which isn't very often!

[steppenwolf]

These two images represent a really good start. Flats are detailed in the book, you naughty boy!

To darken the background, pull the bottom left hand quarter of the plot in Curves down a little - but, remember that the night sky is never inky black from the UK so don't overdo it or your images will start to look unnatural. You can 'lock' the plot's dark point before applying a stretch by Control Clicking on the background - this anchors the background level on the curve of the plot.

The ED80 is a truly excellent telescope but it will show star distortion without a flattener.

[kirkster501]

Thanks all for your words of encouragement I am on a very steep learning curve.... I think I need to start guiding pretty soon though and try to get my exposures a little longer.

[ollypenrice]

Your Curve isn't optimal here. A first curve usually looks like this, rising steeply and then curving smoothly to a straight line to the finish. Don't worry about the posterized look of the image. That will disappear as the Curve is applied.

Next operation is to cut back in Levels. Move the black point slider to the right till you get to coherent signal - a strong continuous horizontal data line. This is clipping out noise and maing the most of your range of brightnesses. Don't clip too hard or you'll clip real signal. Leave room to make a last clip as your final operation before saving the finished image. A good background value is around 23.

Further iterations of Levels and Curves will follow but the lift needs to become less aggressive and will need to roll off earlier.

In the image above the core of the galaxy will need a separate stretch of its own but that's a different story!

Your results are superb for a first attempt. Very well done indeed. Focus is good, the sky is also good. Flats are needed to lose the vignetting which is strongest in the green channel (by eye.) GradientXterminator or DBE in Pixinsight would deal with that easily for the time being.

Olly

[kirkster501]

Thank you Olly. So you do curves first. Interesting , I will have a go at that. I am really struggling with a M31 I did with 60mins of data that is rubbish after DSS but individual 2 min subs are great..... Weird.

Sent from my iPhone using Tapatalk

[ollypenrice]

Thank you Olly. So you do curves first. Interesting , I will have a go at that. I am really struggling with a M31 I did with 60mins of data that is rubbish after DSS but individual 2 min subs are great..... Weird.

Sent from my iPhone using Tapatalk

Sorry, no, you do Levels first. You make sure that the black point starts where your data starts and that your white goes all the way to the right. If they don't, move the sliders inwards to meet the respective ends of data line. Becuasue of the stacking software and routine I use I don't, in reality, need to check this because the stacking software gets it right.

I should have been clearer.

Olly

[Black Knight]

Your Curve isn't optimal here. A first curve usually looks like this, rising steeply and then curving smoothly to a straight line to the finish. Don't worry about the posterized look of the image. That will disappear as the Curve is applied.

Olly

Olly I had no idea the first iteration of curves could (or even should) be quite as agressive as this! All this time I've been making really teeny tiny curves .... which probably explains why I never seem to get much depth out of my images (and why others say "there's plenty more to be gotten out of that image")! Certainly a eureka moment for me!