First attempt at imaging

[ianpwilliams]

What time of night did you have to stay up to take these? I admit to not trying at all in the summer as I don't do late nights.

I have no tips for Gimp I just played with levels.

I watched that guy who images using camera and static mount as his video covered a bit of everything. I have shared it before I think.

And read lots on this site when other members post.

Next time I have a go I will take raw and jpeg to see what a raw is like in dss. I guess using RAWS for me will be down to if my pc can cope.

What kind of levels do you modify in GIMP?

[Atreta]

I too find difficult to process raws after beeing stacked.

all my images processed were made using jpegs.

[Atreta]

Just did a try unchecking the median filter before stacking and i improved a lot.

More stars are showing and when i moved the sliders the details popped out too.

maybe you can try that also, uncheck the median filter option and compute the stars again.

don't know if it's related, but here improved quite well.

[ianpwilliams]

The issue I'm having is the difference between the file formats before I even begin registering or stacking. Here is the "Light 1" JPEG in DSS (which is how it looks in everything else), and the "Light 1" RAW in DPP (as it appears in everything else), and in DSS, much darker.

[Atreta]

It is darker because it wasn't "developed" yet.

after you stack it you will move the rgb/k levels and saturation.

here is my stack before and after i did it, in the after picture i didn't raise the saturation yet.

[ianpwilliams]

Oh I see. Maybe that's what "raw" means - it hasn't been "developed". Although I followed the tutorial through to the end (including the RGB, saturation, and luminescence stages, and it was still extremely dark when I'd finished. I'm pretty sure I did an ok job at the RGB stage, so maybe the saturation and luminescence stages needed more attention. I'll have another go with the RAW files then.

So for the stacking mode, did you go for "Average" instead of "Median Kappa-Sigma Clipping"?

[ianpwilliams]

Hold on, were you referring to unchecking "Reduce the noise by using a Median filter" option in Register Settings? Because I've always had that unchecked (based on the tutorial).

[Thalestris24]

Hi

'RAW' refers to the image file containing raw data which, in principle, means uncompressed and containing all the detail recorded by the image sensor. In practice, dslrs seem to do something to the data, possibly run length encoding or something which presumably doesn't involve taking anything out.

Louise

[happy-kat]

Sorry not Levels it is Curves I sue to tweak the final image.

[ianpwilliams]

Oh ok.

Is it possible to save your DSS project after registering and stacking are done, but before RGB etc? It'll take hours to stack the RAWs again.

Also, does anyone know what "2xdither" means?

[Atreta]

Yes it is, just click on save picture to file.

can't help with the second question.

[wxsatuser]

The issue I'm having is the difference between the file formats before I even begin registering or stacking. Here is the "Light 1" JPEG in DSS (which is how it looks in everything else), and the "Light 1" RAW in DPP (as it appears in everything else), and in DSS, much darker.

Stop using jpegs.........use only RAW.......set you camera to RAW only.

You want the full bit depth/tonal range, you won't get it with jpeg.

The RAWs may or will appear darker, you job along with software is to stretch that data to get a reasonable image.

The only time jpeg comes into the equation is when checking the in camera histogram.

The in camera histogram is a histogram of a jpeg, of the RAW image.

The RAW image histogram will more than likely be shifted further to left, ie darker.

[ianpwilliams]

I'd prefer to use RAW if I can (as long as my PC can handle stacking them), I just need to know how to process that stacked image so that I can bring all those stars back. Because if I don't know how to do that, then JPEG is my only option, as demonstrated by the pictures I uploaded, where the stacked RAW image is "The Plough" only (I've since learned that it's not Ursa Major, because the rest of Ursa Major isn't visible), whereas the stacked JPEG contains lots of other stars as well (albeit at lower quality).

So if anyone knows of any good tutorials for getting the most out of DSS after stacking, and also processing with GIMP, then that would be great.

[wxsatuser]

What exposure are you using?

See Atreta's right hand image.

He has DSS histogram about right.

Get yours like that.

All channels aligned and the steepest portion of the curves line should run approx up through

the lower third section of the aligned channels.

Set the saturation to around 15>20% and you can save as is.

You will need to still stretch it a bit later.

If you save embedded you will need decent software to bring out the best with levels and curves.

[ianpwilliams]

I took ten 6-second Lights and the same as Darks.

As for the DSS histogram, I like to think I did an ok job on it (I got it close to what the guy in the tutorial had).

I'll try it again, this time stacking the RAWs again, and see what I can come up with.

[ianpwilliams]

Actually, I've still got a TIFF file that DSS created when stacking all the RAW files, so maybe I could process that in GIMP or something, rather than waiting hours to stack them again? I'm assuming the data (ie the rest of the stars) will be in there somewhere?

[Alien 13]

You can load the TIFF back into DSS by using the "open image file" option then reprocess the colour etc as much as you want it normally only takes a few mins.

Alan

[ianpwilliams]

Thanks, had a quick go, but the image is still very dark, with virtually no stars other than The Plough. I'll play around with it some more.

[ianpwilliams]

I managed to bring out the stars more in both versions anyway, having just played around with the curves (i.e. starting out at zero, and then rising sharply to the maximum level). Still can't solve the mystery of the RAW vs JPEG situation though. But I suppose it doesn't matter so much with this basic image anyway.

[toxic]

an easy way to get focus with a lens or scope is to get an old lens cap and cut 2 holes in it 10mm for lens cap then go to live wiew at 6400 iso zoom in to a bright star and focus till you only get 1 star.

[Atreta]

Ian,

Give a try with the 3.3.4 version of DSS, i forgot to mention that i was using it in my previous posts.

To me the difference between both versions in development is quite noticeable using raw files.

Maybe it will be better for you too.

here:

[ianpwilliams]

an easy way to get focus with a lens or scope is to get an old lens cap and cut 2 holes in it 10mm for lens cap then go to live wiew at 6400 iso zoom in to a bright star and focus till you only get 1 star.

lens cap focus aid.jpg

Thanks, will bear that in mind

[ianpwilliams]

Atreta, I think I already have that version, having had to upgrade anyway because I was getting that common issue where the image is tall and narrow