Hi
Was pressed for time last night but managed to squeeze this in. Orion area with Canon 50mm f1.8 lens @f3.5, with the IDAS LPS filter sitting on top.
3x5 mins ISO400, modded 350D. The focus is so fine that moving the focus ring a fraction of a mm makes a big difference. I took 5 sec. test images to check focus till the faint stars were only a pixel in size.
Note Barnards Loop in the image and the very faint Witchhead Nebula (near bottom)
The hassle with widefield imaging is the greater chance of satellite and aircraft intrusion, as we can see from bottom left.
Digital imaging never ceases to amaze me. To get this in just 15 mins from a light polluted place...... Only gas hypersensitized 2415 technical pan film would get anywhere near it.
Scott
Nice wide field Scott ... I think you should maybe add another 3 frames or more to bring out some greater detail in Barnard's Loop and probably show up the Witches Head better as well ... nothing wrong with this image by the way ... well done.
I like this shot too.
I also note how clearly visible the ultra-red variable star W Ori appears, which is at the bottom centre of the posted image. This star appears brighter than 6th magnitude it appears to the telescopic eye - agreeing almost with the 6.2 of 27th January 2009.
This is a semi-regular variable, whose range can be between 8.2p and 14.2p, but sometimes this is quoted as 5.9v to 7.7v and shines as a carbon star of spectral class C5,4(N5). The mean magnitude for previous data suggest an approximate long period of 2450 days (6.7 years!) It is presently a wonderful time to look for it.
(A magnitude charts is available from the AAVSO at; http://www.aavso.org/cgi-bin/shrinkw...RI/WORI-AB.GIF )
I have taken a snapshot of this image to highlight W Ori and an identifying finder chart, both being attached below.
Hi
Was pressed for time last night but managed to squeeze this in. Orion area with Canon 50mm f1.8 lens @f3.5, with the IDAS LPS filter sitting on top.
Scott, how do you mean the IDAS "sitting on top" - do you mean not threaded? Had wondered if there was some way I could use my IDAS for widefields.....
Heres a much deeper shot. Oddly enough no air, or space craft intruding this time despite the much longer imaging time.
Yes another warm night, but thermal noise didnt seem too bad.
Yep, I have the LPS filter simply sitting on top of the lens (it will sit there without touching the front lens element. In fact it fits underneath a lens hood that screws on with its own UV cover filter, but the idas filter will just sit there itself (as long as the camera is pointing upwards). Houghy says its possible to get step down rings to screw it on properly, but yes nebula filters do work well for wide field work.
This effort is 19x5 mins ISO 400, masked with 2x30 sec ISO 200, again with the lps filter and modded 350d, 50mm f3.5.
Larger version here
Lots of light pollution, and lights from next door, shows what can be done from suburbia
There'll be a plethora of wide field Orions soon.
I'll be giving it another go now that I have the mount to do a half decent job.
Just waiting for clear skies.
Just gets better and better.
Sorry for all the questions Scott - were you guiding for these?
(JJJ is right - there's obviously plenty of us fascinated by these orion widefields....! )
Thanks.
No worries Rob, yep I was guiding, and trying to be as accurate as if I was using my 6 inch scope rather than the lens for imaging. I had the camera piggybacked onto my rig. When I check focus I have the lens wide open at f1.8, the tiniest adjustment makes a difference, I keep tweaking till faint stars are just 1 pixel dots, I then stop down to F3.5 knowing I have perfect focus. Its only a cheap lens, so there is still some coma
Scott
W Orionis : Sticking out like the proverbial,,,,
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