Some wide field experiments

[michael.h.f.wilkinson]

I had a bit of a fruitless hunt for noctilucent clouds last night, but at least tested the Samyang 10mm F/2.8 and my old Contax mount Carl Zeiss Distagon 28mm F/2.8 on the area centred on Cygnus.  I I forgot to switch to raw, so these are some JPEGs stacked in APP. No tracking was used, so some star trailing visible.

First up the Carl Zeiss Distagon 28mm F/2.8, 1 frame 20s, ISO 400, 2x 20s at ISO 800, on my un-modded EOS80D:

four frames at 20s with the Samyang 10 mm F/2.8 at ISO 800

I used full aperture in both cases. In the lower left of the latter image M31 is visible, right near the edge. I need to do this properly, non a tracking mount, perhaps one stop down in the case of the Samyang, capture loads more data, use the modded EOS 550D, and use flats and darks, but I am still quite pleased with the potential.

I also took two shots of the lack of noctilucent clouds with both lenses at full aperture:

Samyang 10mm:

Zeiss 28mm:

 

[Rob]

They have come out nicely.. good stuff.

Rob

[MarsG76]

Those milky ways are soooo speckled with stars...

 

[MarsG76]

I think that if you used the "Despeckle" filter in PS, you would end up with a milky nebula and no stars.... ?

 

[michael.h.f.wilkinson]

1 minute ago, MarsG76 said:

I think that if you used the "Despeckle" filter in PS, you would end up with a milky nebula and no stars.... ?

 

Don't have PS, but have developed algorithms for so-called area opening filters (wrote some papers on that), which can do the same. These data aren't worth much more effort. I will try to get much more, using a tracking mount (my EQ3-2 will do nicely) and see what that does. If tonight is clear, I might even capture a couple of hours of data without problems. Then I will start doing some serious processing. I might go for the Zeiss first, as its less wide view is less likely to pick up LP from my location.

[MarsG76]

Keen to see the results...

I exposed parts of the sky using my 50mm and 150mm Sigma EX prime lenses the other night, all tracked and guided while piggy backed on my 8SE... I'm still to stack and process, but single exposures already look promising.

[michael.h.f.wilkinson]

3 minutes ago, MarsG76 said:

Keen to see the results...

I exposed parts of the sky using my 50mm and 150mm Sigma EX prime lenses the other night, all tracked and guided while piggy backed on my 8SE... I'm still to stack and process, but single exposures already look promising.

Looking forward to the results. Might also try the 50mm F/1.4, or the old Zeiss 85mm F/1.4 as well (choices, choices )

 

[MarsG76]

23 minutes ago, michael.h.f.wilkinson said:

Looking forward to the results. Might also try the 50mm F/1.4, or the old Zeiss 85mm F/1.4 as well (choices, choices )

 

Why does it have to be choices? Do it with them both...

[michael.h.f.wilkinson]

Just now, MarsG76 said:

Why does it have to be choices? Do it with them both...

But not at the same time! I need more modded cameras!!

[MarsG76]

1 hour ago, michael.h.f.wilkinson said:

But not at the same time! I need more modded cameras!!

Couple of hours with one lens, meridian flip, couple of hours with the other...

[michael.h.f.wilkinson]

1 minute ago, MarsG76 said:

Couple of hours with one lens, meridian flip, couple of hours with the other...

Nights are too short here at 53 north. Later in the year I should be fine

[happy-kat]

The samyang has really tight stars but way more vignetting but I'd use that one as the milky way looks very promising.

[MarsG76]

30 minutes ago, michael.h.f.wilkinson said:

Nights are too short here at 53 north. Later in the year I should be fine

Right ok...... how many hours of Astro dark??? Halve the time on each...

[michael.h.f.wilkinson]

1 minute ago, MarsG76 said:

Right ok...... how many hours of Astro dark??? Halve the time on each...

No real astro dark yet, but getting there. It does get dark enough, sort of for about an hour. One advantage of the 50mm and 85mm is tha at F/1.4 I would be grabbing data on fuzzies 4x faster than at F/2.8. I will run some trial shots this evening should weather gods allow

[MarsG76]

1 hour ago, michael.h.f.wilkinson said:

No real astro dark yet, but getting there. It does get dark enough, sort of for about an hour. One advantage of the 50mm and 85mm is tha at F/1.4 I would be grabbing data on fuzzies 4x faster than at F/2.8. I will run some trial shots this evening should weather gods allow

Cool, I hope to see your results...