400mm f5.6L "First Light" - M42

[Hagar (Doug)]

Very nice Doug, detail, colour, focus and depth look great. Just those pesky satelites.

[dugnsuz (Doug)]

Originally Posted by marc4darkskies

Verrry nice Doug!! An excellent rendition!

Cheers, Marcus

Thanks Marcus - nice when a new toy lives up to one's expectations.

Originally Posted by Dennis

Hi Doug

I used a custom mask designed and sourced my H0ughy for my Vixen 102mm refractor – it is a little oversize for the Canon lens but it hangs on the 400mm F5.6L lens hood by a thin foam ring that I glued onto the mask. If I remember correctly, I had to choose a bright star (at least Mag 1) and used Remote Live View fully zoomed in.

I tried the same mask on my 70-200mm F4L and had a little difficulty as the spikes were quite small in extent, but after I took a 30 second image and downloaded it, I could see that that focus was good as can be seen in the attached 40D full frame shot, down-sampled to 800x533 pixels.

I know that Ron at Sirius Optics sells Farpoint Bahtinov Masks with the smallest size covering the range 2.5" - 4.5". These have x3 locating screws at 120 degrees located in slots at the outer edge that can slide in/out radially, so the mask will fit snugly on the lens hood.

I guess that once you have used Remote Live View zoomed in, it would be best to then take say, a 5 sec shot, download it and inspect it full size to confirm best focus?

Cheers

Dennis

Cheers for the information Dennis - I will investigate further.

Originally Posted by Hagar

Very nice Doug, detail, colour, focus and depth look great. Just those pesky satelites.

Thanks Doug - M42 seems to be a magnet for satellites.

Doug

[h0ughy (David)]

well looks like you have a nice imaging lens

[dugnsuz (Doug)]

Originally Posted by h0ughy

well looks like you have a nice imaging lens

Thanks Dave - yes, I landed on my feet with this one I reckon!
Cheers
Doug

[multiweb (Marc)]

Great shot. Wealth of dark nebs in there. Nice work.

[dugnsuz (Doug)]

Originally Posted by multiweb

Great shot. Wealth of dark nebs in there. Nice work.

Thanks Marc - I've binned all the obvious satellite trail subs and will hopefully add to the remaining subs around the new moon if weather permits.
Doug

[Octane (Humayun)]

Doug,

Why did you bin them? What stacking algorithm are you using?

At least in IRIS, kappa sigma stacking removes anomalies. I'm sure MaxIm's sigma clip works the same way, too.

It's too painful throwing sub-exposures out, unless the stars are uber-wonky : )

H

[dugnsuz (Doug)]

Originally Posted by Octane

Doug,

Why did you bin them? What stacking algorithm are you using?

At least in IRIS, kappa sigma stacking removes anomalies. I'm sure MaxIm's sigma clip works the same way, too.

It's too painful throwing sub-exposures out, unless the stars are uber-wonky : )

H

C'mon H I'm a perfectionista!
Doug

[dugnsuz (Doug)]

Rethink - as usual you're probably correct H

So, all is not lost - I keep the original RAWs on the camera CF card and also d/load them to the astro laptop...Belt N' Braces!!!

I'll try restacking with your suggested settings (or their ImagesPlus or Nebulosity equivalents)