Capture of the Cone Nebula in Monoceros with the 5DH. This nebula is not very bright. This also is a quick process from Raw to 16bit tiff stacked in Registar adjusted in Photoshop at 4AM.
Details 5X6min exposure ISO 1000 300mm @ f2.8, Hutech Nebula Filter,in camera noise reduction ON.
FOV is 6.8X4.5 degrees.
Bert I have just seen the same thing with a post by Astroboy. A wonderful photo you have taken. Might I ask 1 small favour, PM astroboy and see if you can merge the two images to see what may come of it, there is heaps of detail in both and they are bth sharp shots. Congrats mate, top shot!
Such a faint object is hard to shoot in colour are you able to get under dark skies and go for a long exposure.
I wonder if its posible to use a Ha filter and work in B&W so you could shoot long exposures from any site.
How does the lens perform at F4? does it tighten up the stars at the corners.
keep 'em coming
I wonder if its posible to us a Ha filter and work in B&W
Zane, how do you think it would look using a B&W Ha shot similar to the one you did in your thread as a luninance channel. Would that be likely to increase resolution/detail in Berts shot?
my wife loves coffee and so every weekend the family trots into town to Gloria Jeans for a fix. Even the 2 yr old has a buba chino.. Right next door is our states best camera shop. And so every weekend I drool at the Canon cabinet with the 5, 20 and 350. I look at the price tag and convince myself once and for all that it is not necessary.
AND THEN YOU GO AND CONVINCE ME I SHOULD BY POSTING THESE IMAGES!!!!!!
Thanks for all the comments. But don't forget one thing these shots are all taken at F 2.8, which is as you know twice as fast as F4, four times as fast as F5.6 and eight times as fast as F8 and so on. To record this dim nebula at the same signal with F8 say would take an exposure of 8X6=48 minutes or sum (rather than average) eight exposures of six minutes each.
To record an image of a point source (ie star) depends purely on aperture size and is independant of F ratio. To record an extended source F ratio is the main consideration and is independant of focal length.
What I want do do with the 5DH is to make large moderately detailed mosaics with the 300mm lens so that all the images we see at higher magnification and detail can be seen relative to their environment.
Here a small pic of Alpha, Omega and Beta Centaurus and if you look carefully Cent A. and a shadow of a bit of tree. Also the Jewel Box.
The reason i asked about the F4 performance is it may clear up the coma off axis so the full format and resolution of the 5D can be used , and I imagine will be a big help if you want to make mosaics , I wouldn't think you would need to stop down to F8 though.
Back in the days of film imaging just about every lens had to be stoped down to some degree to get the off axis performace up to scratch and film is quite forgiving compared with digital.
I just think its better to take a longish shot , say around and hour at F4 and get les noise and aberations . at the start of CCD imaging years ago people were amazed with what a short exposure could do , but now most people are imaging for several hours and getting much better results .
Just gets to how much effort , time and expense a good result is worth and what our definition of a good result is ,which changes as we get more and more into the hobby .
After saying all that , the main reason for building the 10" F3.5 was so guests could get a good image fast ( under one hour ) but still will get better ones shooting longer.
Only the really bright stars show any aberrations. Using the lens at F4 would tighten up the brighter stars but halve the speed. Heres a high resolution picture of Carina taken with an 80ED @ F7.5 and the 5DH. Field curvature among others is a problem here.
1.6M
FOV 3.438X2.292 deg. http://users.bigpond.net.au/avandonk/CAR01ac.jpg
The ED80 certainly looks like it needs a field flattener , the Borg 85L should be ideal will give full coverage for the 5D and the stars are 13 micron at the corners .
One thing I've noticed about all the 300 F2.8 shots I've seen is there is more distortion on the right than the left , what could cause that ?
I can't say I have noticed left to right asymmetry but this would be due if present to misalignment of sensor to the optic axis of the lens. Don't encourage me too much, a Borg would be nice but which one? One good thing about the borg system as it is modular buy one bit at a time and minimise GST imposed by customs.
The DGL is the one you need for 35mm coverage and a 2" tube to fit your focuser , a bit expensive ( $349 ) but at least you know what your getting , the Tele Vue stuff is quite vague about image quality just saying it flattens the focal plane and as you know the Borg camera adaptors suffer less fron vignetting.
Havent ever had to pay cumtoms for Hutec stuff , posted gear seems to go straight through .
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