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Red sky in Cepheus

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#1 Michal1

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Posted 15 February 2013 - 03:23 PM

A part of sky very rich for red nebulae, the southern part of Cepheus. The edge of IC 1396 is visible at the bottom side.
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Takumar 400mm, f/5.6, 69 min, Kodak E200

M.

#2 Michal1

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Posted 20 February 2013 - 02:43 PM

The image can now be seen here in higher resolution (5.9 Mpix).
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#3 Nightfly

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Posted 20 February 2013 - 07:07 PM

Enjoyed the larger image very much Michal. The 400 does very well to control CA overall. Your exposure time / f-ratio combination worked well and this is a decent scan. Keep up the great work.

#4 THEPLOUGH

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Posted 20 February 2013 - 07:36 PM

Wow............ :bow:

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#5 Nebhunter

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Posted 23 February 2013 - 06:58 PM

This is really good Michal. Lens is doing a good job as well. I've found that with longer exposures the nebulae especially the faint ones benefit, but many times the stars loose colour saturation and depth. It's a fairly new lens for you so I would imagine some experimentation to come?

Igor

#6 Michal1

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Posted 26 February 2013 - 02:27 PM

Thank you all!
Igor, I haven't noticed the films would be less or more exposed than that with other lenses at the same f-ratio and exp. time. Have you found the optimal time for your 400mm lens to be different? I've tried shooting the lens wide open at f/4, but vignetting was quite strong. I'm going to upload some unprocessed frames from the lens and comment them here. I'm going to experiment with shorter exposures times around 30min with all of my lenses next season. Oliver Stein (estellar.de) often used to combine two 30min pushed frames with outstanding results.

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#7 Nebhunter

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Posted 28 February 2013 - 09:50 PM

Michal - Jim and I have experimented quite a bit with exposures with E200. I've taken some really long at 150 minutes with the f/7 Tec - and up to 90 minutes with the 400 at f/5.6. We have compared these and similar to some of Jim's 30 to 45 minutes and were quite surprised at the richness of the star colours, regardless of push. Nebula are a different story, and really dependent upon other factors eg: NGC7000 vs Veil.

Shooting longer seems good for fainter nebs, but stars seem to wash towards white. Sure, there is still colour, but not the vivid brightness of the shorter exposure. I am quite familiar with Estellar and his work with the 400 EDif lens and have studied his exposures. However, he did shoot a high altitudes above the LP in most cases.

I must agree with his stacking of frames. It brings out the best from both frames. Especially with bright globular clusters. Always difficult to produce a sprinkling of stars with them instead of the typical blown out highlights.

I'm hoping to do more of that this summer, if sky conditions co-operate. Last summer was almost a total loss for anything better than average conditions. Sun spot activity is near max - and so getting a really dark sky is just not happening compared to some years ago. Need to do more visual anyway before my eyes really go south due to floaters.

I've standardized exposures to f/5.6 at 50-55 minutes with push 1. A bit less on some objects, and a bit more on fainter neb. But that is for my area with some light domes in the south area, and being close to Lake Erie - a very large body of water about 10 km away. Flat farmland all around me and subject to light to very heavy fog or dew during spring and fall. Your area will be different and that is why I was referring to the experimentation.

Igor






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