M51 with more data

[steviemac500]

I added another 2 hours worth to M51 so 6 intotal and it's come out OK but i cant helpp feeling a little disappointed. When you consider how many lights have gone into this and then compare the image to the recent one below (irt75914) i dont think they stand together at all. I would have liked to have seen more colour but it's still something i struggle with and i think i may have over sharpened it too. I know this was taken with an ED80 and the other with the 200P so it has been cropped to get some size into it but i dont really know how to get the image sharper with more detail. I'm also using PS, not Pixinsight which probably doesnt help. In total 79 subs @ ISO1600 X 5 mins each. 40 Bias, 25 Flats, dithered using APT and PHD2.

Am I expecting too much? All comments/critiscism as always are greatly apprecited.

Steve

[lrt75914]

2 hours ago, steviemac500 said:

I added another 2 hours worth to M51 so 6 intotal and it's come out OK but i cant helpp feeling a little disappointed. When you consider how many lights have gone into this and then compare the image to the recent one below (irt75914) i dont think they stand together at all. I would have liked to have seen more colour but it's still something i struggle with and i think i may have over sharpened it too. I know this was taken with an ED80 and the other with the 200P so it has been cropped to get some size into it but i dont really know how to get the image sharper with more detail. I'm also using PS, not Pixinsight which probably doesnt help. In total 79 subs @ ISO1600 X 5 mins each. 40 Bias, 25 Flats, dithered using APT and PHD2.

Am I expecting too much? All comments/critiscism as always are greatly apprecited.

Steve

Your ISO setting seems a bit high. Aside the noise, however, I think your results are actually amazing. You could upload your files so I could give run them through PixInsight if you want. 

[steviemac500]

Hi, I know what you mean about the ISO but I was under the impression that for my Canon, 1600 was the optimal setting (maybe someone will comment on this). Ill Dropbox the files later if you wouldn't mind having a go with PI?

Steve

[lrt75914]

3 hours ago, steviemac500 said:

Hi, I know what you mean about the ISO but I was under the impression that for my Canon, 1600 was the optimal setting (maybe someone will comment on this). Ill Dropbox the files later if you wouldn't mind having a go with PI?

Steve

My dad's Sony Alpha 77 Mk II has great low light performance but the images still get to noisy for my taste once you go past ISO 800. I have never owned an Canon though, so I couldn't comment on the optimal setting for their models. 

I will be working late today, but I would love to have a go at your images. I will try to process them once I get back home.

 

Patrick

 

 

[bogdog]

16 hours ago, steviemac500 said:

Am I expecting too much?

i would be more than happy with that image,ok there is noise but at iso 1600 there will be 

you will never get hubble type pics from everyday consumer products,all you can do is best with what you have,and from what i see here you have done well

but now you know iso 1600 is a bit much @ 5 min interval as it introduces noise

try iso 800 @ 5 min or more subs at iso 1600 for shorter time maybe 3 min subs but more of them ?

[hjw]

6 hours ago, steviemac500 said:

Hi, I know what you mean about the ISO but I was under the impression that for my Canon, 1600 was the optimal setting (maybe someone will comment on this). Ill Dropbox the files later if you wouldn't mind having a go with PI?

Steve

Hi Steve, nice picture by the way. The ISO range is a bit like the zoom on some cheap video camera. When using the optical zoom you gain information but when using a digital zoom you just increase the pixels. Same with ISO. The sensor has a certain dynamic range where increasing the ISO increases the amount of information captured. When exceeding this range the signal get amplified by the software together with the noise. Each camera has their own turning point and there is information on the net where this point is for different camera models. For my Pentax for example, it somewhere close to 2500. For faint objects I am therefore comfortable at ISO1600 but I also have used ISO3200 before (theoretically 900 increase is real and 700 increases the noise). Absolutely no point going to 6400 or above.

New sensors become better and better. In the days of film 400 was a fast film. My first DSLR (Nikon D50) had a top ISO of 1600. On paper my max ISO is 25600 while there are now cameras going to 400,000+. Noise will also come from how much you have to stretch your image in post processing. I don't think there is a simple rule to follow but a lot of experimenting to be done.

 

[steviemac500]

5 hours ago, lrt75914 said:

My dad's Sony Alpha 77 Mk II has great low light performance but the images still get to noisy for my taste once you go past ISO 800. I have never owned an Canon though, so I couldn't comment on the optimal setting for their models. 

I will be working late today, but I would love to have a go at your images. I will try to process them once I get back home.

 

Patrick

 

 

Patrick, here's the link to the image. I've just realised that i may have forgotten to flatten the layers so its pretty big i'm afraid.

https://www.dropbox.com/s/g593y9z0mu7uce3/Autosave.tif?dl=0

[lrt75914]

22 minutes ago, steviemac500 said:

Patrick, here's the link to the image. I've just realised that i may have forgotten to flatten the layers so its pretty big i'm afraid.

https://www.dropbox.com/s/g593y9z0mu7uce3/Autosave.tif?dl=0

Hi Steve

Did you use DSS to stack your images? If so, what Bit Depth did you use to safe the .tif file. Saving your stacked file as an unsigned integer image might be one of the reasons why you lose so much information in your final image. I will give it a try once I get back home. If you want you could also upload your raw files so I could process them with PixInsight as well. Thank you for the effort of uploading that file to your dropbox folder, though .

Patrick

[lrt75914]

Hi Steve,

I tried to improve the image to the best of my abilities and this is what I came up with:

I have the feeling that the image is slightly defocused, but other than that I would be very happy with your results. Keep in mind that I'm still a novice at this and there will be a lot more that you can do to improve your image.

 

Cheers,

Patrick

[steviemac500]

Lovely, your colours are much better than mine. Can I ask what you did, I struggled to remove the blue but you seem to have it. I'm thinking about switching to Pixinsight as I currently use PS6 but can't decide if the money is worth it?

[lrt75914]

7 minutes ago, steviemac500 said:

Lovely, your colours are much better than mine. Can I ask what you did, I struggled to remove the blue but you seem to have it. I'm thinking about switching to Pixinsight as I currently use PS6 but can't decide if the money is worth it?

Hi Steve,

Unfortunately I can't tell you weather you're going to like PixInsight or not. It is a very comprehensive program that allows you to tweak a lot of stacking and image processing parameters to your liking. That flexibility, however, comes at a price. Some people find its learning curve a bit steep and the documentation is somewhat lacking. There are, on the other hand, a lot of people that praise Startools for it's accessibility and intuitive layout, while I couldn't get a single usable image out of that particular piece of software. It's probably best if you download the trial versions of these programs

• PixInsight
• StarTools
• Nebulosity

and see weather you prefer one over the other. These are all just toolboxes and all of them will produce great images. It's just a question of which one will work the best for you!

Workflow:

1. Dynamic Crop to remove stacking artifacts
2. Color Calibration
3. Background Neutralization
4. Denoise using the inverted image as a mask (this is done to reduce the noise in areas without much signal information while keeping the bright parts of your image fairly intact)
5. Masked deconvolution (sharpening) of the Galaxy
6. Histogram Transformation
7. Curves Transformation (Contrast and Saturation)
8. Multiscale Contrast Sharpening (Astra Image)

 

Cheers,

 

Patrick

[raathistle]

That edit is lovely, it looks like a different image.

Maybe I gave up too soon on Pixinsight - it does have quite the intimidating interface

 

[toilandtrouble123]

I'd be astounded at producing that! Well done!!!

[iapa]

On ‎12‎/‎05‎/‎2016 at 04:09, steviemac500 said:

Hi, I know what you mean about the ISO but I was under the impression that for my Canon, 1600 was the optimal setting (maybe someone will comment on this). Ill Dropbox the files later if you wouldn't mind having a go with PI?

Steve

There was something I read in the past few months - it got quite detailed around sensors/noise and such - that summarized that ISO800 is optimal for recent Canon cameras.

I'd settled on that setting for my 600D/&00D and 70D before I came across the article. (really need to keep track of these things somewhere)

[bendiddley]

I think your image is amazing. I would be very happy with that. 

[wornish]

I think your original  image is amazing. The PI processed version done by Patrick certainly brings out more colour.

Pixinsight does have a steep learning curve and it allows you to do hundreds of different adjustments, but the more you use it the better results you can achieve.

 

[Hicks]

Comparing the original and Patrick's it just shows how different processing can make the same image look.

I'd be happy with either of the two images although Patrick's version appears to be a little less noisy and the colours a little less blue?