Impressive.

I recently gathered 6min of m42 with a Samyang 135 and the astrotracer and will give it a go using you guide. Not that the result will be anything to talk about but it’s a fun exercise anyway.

Very nice Pete! I think APOD is calling, you're doing our little Pentax social group proud!

Hi Pete
Just watched your video and it's brilliant
Neil

Maybe 6 minutes of light are not enough to see the advantages of the method but perhaps enough to understand the principles. Little integration time means few photons and a lot of noise comming up when you stretch the data. But M42 is bright and I wish you good luck anyway. Please show us the result no matter how it looks like

So this is what I finally arrived at. Had a little problem around the Higpass part in the tutorial, I guess the group should be in linear light mode? But what about the different filters inside the group? I ended up with overlay after trial and error as that seems to work...

Very good result for just 6 minutes of interation time. And though it must be a heavy crop the stars are quite decent. So it worked!

As I wrote in step 7b the highpass filter layers have to be in soft light mode. Overlay mode or a combination with soft light works too. Be sure to adjust the layer and the group opacity to have a decent effect. Use masks on the layers and the group to control strength and location of the effects. So you can paint sharpness into the image with a smooth brush of low opacity. Remember you can copy masks the to other layers by using ctrl-click on the mask to get a selection and then open a new mask on the layer to copy to with the selection active.

Did you test your "normal" workflow against mine?

Yes it's heavily cropped, almost 100%.
This was a very good exercise as I did learn some new tricks that I hadn't done or even thought about before. So thanks.

I tried my "normal" workflow and realized that I had messed up a little in the beginning of the process right before stacking in GRIP (I use GRIP instead of DSS, mainly because it's faster and works in 64bit) so I actually got a little more clouds, however the stars are not as clear so filtering them out is a clear plus. Also I like the noise reduction with a reverse mask, that was a neat trick.

Anymore details on GRIP would be appreciated. I have never heard of it.

Likewise. I've never been able to get DSS to work in 64bit Windows 7 or Windows 10.

grelf.net - Photography with Java

[quote=Gimbal]So this is what I finally arrived at. Had a little problem around the Higpass part in the tutorial, I guess the group should be in linear light mode? But what about the different filters inside the group? I ended up with overlay after trial and error as that seems to work...

Very nice! I have something to strive for!

Not to continue to be off topic, but I recently did the exact same with the K-1 and the 135mm, and honestly I like your result better. Which ISO and shutter speed did you use? I was trying ISO 200 and 30s. I recently tried a bunch of shutter speeds to find the astrotracer limit. It seems 50s is the max I can get, but 30-40 is much safer.

Pete, as far as your workflow, my plan (if I have clear skies), is to do that mosaic with m42, horsehead, flame, m78, and Barnard's loop this weekend with much more data. I downloaded stellarium (awesome!), and have it all mapped out. I even made a bahtinov mask and tested it last night (worked!). Once I get that data I'll be going through your workflow step by step.

Hi Jeff,

I had a similar "winter project" this year but I miserably failed because of insufficient focus (have no mask for the 50/2.8 macro), big gradients because of the low azimuth of the constellation under light polluted skies and too many stars in the big fov. And because of the LP and low azimuth I was limited in exposure time and did not get enough photons per frame from the DOSs under the balance. I will give it a new try next winter.....and again a bit wiser !

But as I saw in Stellarium the constellation rises up fairly high in your skies. I would like to note that using good flats is essential for this enterprise. I recently shot very good and easy flats by pulling a white t-shirt over the lens and press a white tablet screen against it. I will stay with that method. And I would also recommend to shoot minimum way more then 2 hrs of intergration time because some of the DSOs in the fov are quite dim for an unmodified camera. Finally I would propose to shoot a series of some ten or so lights with shorter exposure for the bright core fom M42 and to get better stars for blending in at the very end of the workflow instead of the brighter and less defined stars of the main series. For this purpose it is necessary to define a reference frame in the bright series, stack it and use and reference this frame also in the dark series stack to have aligned results in the DSS stacks.

So good luck and clear skies for you Orion Project !!

I used iso100, 30sec and f2.4. I had to stop down a little to avoid blowing out the center part.

GRIP is a little different in usage so can be weird at first, for instace there is no “undo” so be sure to always copy the result and play with that so you can discard the current window if regreting something and then start again with a new copy. But once you find the right workflow it’s very fast to use. RobG has the right link for it.