First LRGB Attempt - M101 With 183M

[bobro]

My first attempt at LRGB using a recently acquired uncooled Altair 183M (thanks @Adam J for advice). It certainly takes some thought to work out how to process the image. Plenty of issues to work on - a loose RA coupling didn't help guiding, CC spacing not correct yet and registration wasn't made easier by the lack of a filter wheel - next purchase! Still, it was great to see colour added to the initial lum image taken whilst waiting for the RGB filters to arrive.

All subs 120 sec: 77 LUM, 22 each of RGB. Processed in DSS and GIMP.

[Adam J]

43 minutes ago, bobro said:

My first attempt at LRGB using a recently acquired uncooled Altair 183M (thanks @Adam J for advice). It certainly takes some thought to work out how to process the image. Plenty of issues to work on - a loose RA coupling didn't help guiding, CC spacing not correct yet and registration wasn't made easier by the lack of a filter wheel - next purchase! Still, it was great to see colour added to the initial lum image taken whilst waiting for the RGB filters to arrive.

All subs 120 sec: 77 LUM, 22 each of RGB. Processed in DSS and GIMP.

 

That is a great first LRGB, certainly got some nice color and detail in the galaxy. Am glad that you are happy with the camera so far, I think it was certainly the best choice for your budget and does not suffer so much from the lack of cooling as some other sensors do as can be seen here.

In terms of things to improve I would have a look at your flats.

If it was me I would make a 130PDS and coma corrector my next purchase over and above a filter wheel. Part of the issues you are having and speak about on your other thread is caused by the 1.25inch focuser on your current scope struggling to support the cameras weight without flex. I think that once you add the weight of a filter wheel to the camera you will really see the limitations of your focuser.

Adam

 

 

Edited June 2, 2019 by Adam J

[Kev M]

Thats nice, I would be more than happy with that.

[bobro]

16 minutes ago, Adam J said:

In terms of things to improve I would have a look at your flats.

If it was me I would make a 130PDS and coma corrector my next purchase over and above a filter wheel. Part of the issues you are having and speak about on your other thread is caused by the 1.25inch focuser on your current scope struggling to support the cameras weight without flex. I think that once you add the weight of a filter wheel to the camera you will really see the limitations of your focuser.

I find flats a little tricky to judge due to uneven screen illumination of my laptop, so I look at the sky background values using GIMP. Some gradient likely came from the sky background (not very dark!), though I tried to remove it.

No doubt purchasing a 130PDS would improve things a lot, especially as I shortened the main tube on my Meade reflector to allow a DSLR to come to focus. The side effect of pushing the camera outwards doesn't help the focuser. I still have the 150PL to check out with the new 130M camera. Even with x2 binning it's likely oversampled with my setup at 0.8 arcsec/pixel, but let's see how it goes....

Bob