ngc7000 YANAN

[alacant]

Yet Another NAN. Sorry folks, I know everyone does this. I tried a different composition at least and -gad forbid- I didn't use the dreaded ed80 either! 2 1/2 hours -slowly getting there- with a Canon 700d.

Clear skies, thanks for looking and do tell me what I could improve.

[gnomus]

Very nice.

[emyliano2000]

Another great photo. I don't know how you do it. How do you find your targets and see how to fit them in the frame? I use stellarium to find my targets and see how to rotate the camera to fit them nicely in the frame but there are so many DSOs not showing. 

Do you search the web to see how the colors should be? For example my last photo is the fireworks galaxy and NGC6939, they are both nicely fitted in the frame but I can't get the colors of the galaxy right. I'm still processing it. 

Emil

[alacant]

19 minutes ago, emyliano2000 said:

How do you find your targets

Hi and thanks for your post. 

I use Cartes du Ciel. There are images you can overlay on the charts. They help with the framing. The easiest way is to zoom and nudge the mount to where you want it. If you want it really accurate or you know the centre you want, you can plate solve it. APT's PointCraft is good for that. Does Stellarium have anything similar perhaps?

23 minutes ago, emyliano2000 said:

Do you search the web to see how the colors should be?

I find colour the most difficult part of the processing. By far. Yes, you can have a look at other images but usually there is so much discrepancy, it gets more rather than less confusing. I suppose we can console ourselves in that anything is better than those awful blue and yellow snaps, a craze which originated with the HST I think! Conclusion: dunno. Is there a correct colour for DSOs?

36 minutes ago, emyliano2000 said:

fireworks galaxy and NGC6939, they are both nicely fitted in the frame but I can't get the colors of the galaxy right

Could you post your images? I'm no expert but I'd be interested in seeing an experts POV.

[emyliano2000]

Hi and thanks for the reply.

9 hours ago, alacant said:

If you want it really accurate or you know the centre you want, you can plate solve it. APT's PointCraft is good for that. Does Stellarium have anything similar perhaps?

I use astrotortilla to plate solve which I find it to work really good with Stellarium.

What I do is have a look at the target in stellarium and using the telescope simulator I put the center of the frame where I want it to be. I downloaded all the stars catalogues  up to Mag 16 or 17  in stellarium and that makes it really easy to find a star close or even in the point where I want the center to be. I slew the scope simulator to that star and check what rotation angle I want for that target. As you can see in the printscreens below, I roughly know what I'm gonna see in the photo.

I then save that exact position and rotation in my APT ToDo list for when I wanna take photos of that target. Before I start the session I plate solve using Astrotortilla to make sure the scope and camera rotation are in the position I want them to be. I don't mind if the rotation is off by a few degrees. So far it worked great but Stellarium doesn't show images of a lot of the DSOs. When I'm planning an imaging session I would like to know how the target looks like in the frame.

For example I wanna take some shots of the Elephant's Trunk Nebula. I don't know exactly where to send the scope or what rotation angle to use on the camera because I can't see it in Stellaruim and I don't know how it would look like in the frame. I don't really wanna waste time trying to find the exact position and rotation when I'm out imaging because the clear night in the UK are quite rare and I wanna make the most of that time.

9 hours ago, alacant said:

Is there a correct colour for DSOs?

About the color. Before processing the image I usually google the DSO name and I get different images of it. I might not be right but if the DSO has the same color in a lot of the images than that is what I try to achive.

Can the ISO affect the color. I try as much as possible to shoot at ISO400 to reduce the noise. I also try to shoot 15min+ exposures because of that ISO400. Or can the light pollution affect the color? I bought the IDAS LP clip filter just because I heard you get more natural colors with it and it works really well. I live on the edge of a red zone. I used to own an Astronomik LP clip in filter and most of my photos had a red look that I couldn't remove without changing the color of the DSO I was shooting.

Or maybe I'm not using DSS as I should and that gives me a different colors than the ones I'm aiming for. I know that a lot of people use CCDs and narrowband filters and that is why I look for DSLR images.

I love colors, and I love the colors you get in your photos. I know you use StarTools. I own a copy too and I tried it many times but every time I ended up giving it up and going to Photoshop and lightroom insead because I wasn't even close to getting what I was looking for. :-D

I'm on my laptop now and I'm doing the stacking and processing on my desktop. I'll turn the desktop on and post the TIFF file.Fireworks - NGC 6939 (1).TIF

The total integration time is 4.5 hour made out of 18x900sec lights with 30 flats and 30 bias frames at ISO400. I dithered 12px between frames and that's why I didn't take any darks.

I would've thought I would get a little more details of the galaxy with 4.5 hours worth of exposures. I will try to gather another 5 to 10 hours worth of data to see the result. Maybe I should increase the ISO to 800 too.

OK, on my desktop now.

Here is the TIFF file.

Fireworks - NGC 6939 (1).TIF

I will post the processed photo too in a few minutes. I started processing it yesterday.

And here it is. I stretched it as much as I could. I don't know it I've overdone it or not. The exif temp was 25 degrees. it was a worm night and seeing wasn't brilliant.

Here's a copy edited on my phone

Tell me which one is best please.

Emil

 

[alacant]

Hi. Framing: Looks good to me. You got exactly where it said you'd get. More or less the same workflow.

Colour: The data is really good. Here's a quick play with the sliders and a star mask in gimp -sorry haven't got time to denoise. There's loadsa colour! Oh, and had to crop a long way top and right. If any of those artefacts are left in, it could be interfering with the stretch (?). HTH.

[emyliano2000]

1 hour ago, alacant said:

Hi. Framing: Looks good to me. You got exactly where it said you'd get. More or less the same workflow.

Colour: The data is really good. Here's a quick play with the sliders and a star mask in gimp -sorry haven't got time to denoise. There's loadsa colour! Oh, and had to crop a long way top and right. If any of those artefacts are left in, it could be interfering with the stretch (?). HTH.

Wow. That's exactly what I was aiming for regarding the color.  I did crop it just because of that reason.

Thanks