Red sky in Cepheus
Posted 15 February 2013 - 03:23 PM
Takumar 400mm, f/5.6, 69 min, Kodak E200
Posted 20 February 2013 - 07:07 PM
Posted 23 February 2013 - 06:58 PM
Posted 26 February 2013 - 02:27 PM
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.
Posted 28 February 2013 - 09:50 PM
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.