View Full Version here: : IC4628 with Achro and Nebula filter
avandonk
20-02-2008, 09:08 PM
This is a stack of ten 4 min exposures at an ISO of 1600. They were taken with the Canon 5DH and the 150mm F4.5 SkyWatcher achromat after the Moon set. The Canon was in the fridge at -4C.
Large Image 1.1MB
http://members.optusnet.com.au/~cheekyfish/ic4628.jpg
The red channel was a bit out of focus compared to the green and blue but not bad for an achro. There is no violet ring as the Hutech nebula filter does not pass any shorter wavelengths than Hbeta that cause this.
I used ImagesPlus to slightly reduce the red channel with the star and halo reduction option. This got rid of the slight red ring around the brighter stars.
Bert
EzyStyles
20-02-2008, 10:32 PM
this must be really early in the morning bert, alot of photons and nicely captured. might be just slightly, only slightly too red.
glenc
21-02-2008, 03:07 AM
Superb Bert! I like your series on nebulae.
It is interesting that John Herschel missed this bright nebula.
A fine capture Bert, very detailed.
Cheers
tornado33
21-02-2008, 01:22 PM
Gee its so rich with nebulosity and stars.
The colours of the star clusters really add impact too
Scott
avandonk
21-02-2008, 01:44 PM
Thanks all. I just wanted to show what you can do with an $800 achromat and a nebula filter. Note this achromat is an F4.5 with the FR/FF. That is why there is so much nebulousity. I will collect a HDR data set with the 100ED and 'colour in' all the stars.
If I can get an unvignetted (is that a word?) 150mm diameter F5 achromat to have the same quality stars at the corners as at the center with a full frame. Imagine what you could all do with a C size sensor. You would only need a resonable FR/FF and a nebula or UHC filter.
The other Skywatcher in this size is a 150mm diameter F8 and that would be even better if you wanted tighter stars although you lose the abilty to collect as faint nebulousity.
At a slightly smaller scale you could use an 80ED to collect full spectrum data and say a 120mm achro for the nebula data. Just a thought.
Bert
Alchemy
21-02-2008, 07:23 PM
havent followed the technical stuff too closely here, what focal reducer /field flattener wwere you using as its done a good job. does the DH in the camera designation mean anything, im presuming its modded because of all the red.
sorry for being so ignorant.
vBulletin® v3.8.7, Copyright ©2000-2025, vBulletin Solutions, Inc.