View Full Version here: : Witch from Leyburn
Bolts_Tweed
15-11-2009, 03:26 PM
Had some haze to the east on Thursday night here so imaged the witch hunting faint dust.
Just got the usual witch (was hoping for fainter dust but its beyond the 4 inch televue and 350D if it is there).
Two versions conventional and rotated 90 degrees. Amazing the perception change. Conventionally it looks like my wife yelling "Mark! you are always in that observatory - come and help with dinner" (Boy amI going to pay for that - She is standing behind me - hands on hips - shaking her head going tch tch tch - and laughing).
Rotated it looks like faint reflection nebula with the light streaming from Rigel (lower left off frame) and bouncing back to us - seeing bunnys in clouds is fun but I think the rotated version stands up as an another nice view of a faint nebula.
Televue np101is, Modded Canon 350D, all the usual other suspects, 8 x 20 min subs
Mark Bolton
Benny L
15-11-2009, 03:50 PM
thats a pretty good effort there! definitely not the easiest target to image :)
Its at the top of my to-do list this season
AlexN
15-11-2009, 04:59 PM
I like the horizontal view more mate.. This is a fantastic rendition of the witch head... something that is not often imaged! :) The focal length of your NP101is is 505mm or there abouts is it not? Looks like a lovely target for the wide field APO imagers! :)
You've obviously had a very productive weekend! :)
dpastern
15-11-2009, 05:40 PM
I like the vertical version - just looks *right* to my eyes Mark. That's a very nice target and you've done a good job on it.
Dave
PS probably won't be up @ Leyburn next weekend, prolly won't be able to get Friday off, and have to work Saturday as well...looks like I'm going to be stuck working Saturdays once a month, and guess when it'll be...dark moon...
AlexN
15-11-2009, 06:01 PM
Dave, Could be worse mate.. Im stuck working Saturdays every week... I can sometimes wrangle the Saturday off.. but 90% of the time I'm trapped at work on Saturday... Upside = Overtime rates! :)
dynobolt
15-11-2009, 07:03 PM
Very nice Mark. Is your 350D modded and what iso setting do you use for such long exposures?
Dave
dpastern
15-11-2009, 07:14 PM
overtime rates, what are they?
Dave
Bolts_Tweed
15-11-2009, 08:29 PM
Gday Guys
Thx for the comments but Mr Marples rang me on the drive home tonite and said something doesnt look right with the stars in the Witch and surprise - one of the few times - he's right. Luv ya Pete
I've converted the mild Lucy Richardson filtered image to the jpg not the MLDB image. There are about 3 other steps after this haloed image. Sucks being a blind astrophotographer - I usually use the magnifier when processing but did this conversion this morning asfter 3 nights with next to no sleep. Just got home and im buggered but I'll post the correct image soon - haloed stars annoy the heck out of me.
dynobolt dave : It is modded by Eric so I end up with a red witch from raw data but thats pretty easy fixed. It would be interesting to see how an unmodded 350D does on an all blue object like this (or M45) _ I dont know but i dont think there is a lot difference at the blue end (any ideas Alex or others) Imaged at 800 with in camera NR on. A few smoke and mirrors in processing but mostly just a log stretch in Maxim DL5 and a layer masked colour dodge at about 40% opacity as per Jase's instructions from this forum. Then just a multi layer deconvolution blend but I havent pushed the decon on this object. Im not an expert but if you want any info let me know - I have just started experimenting with this deeper imaging technique and I am learning too.
Makes for a long night taking an image with nr on at 20 minute subs. The biggest pain is reframing after the meridian flip. I'm also building a mosaic of the LMC (Bert inspired me) so I go to that when the orion object is near the meridian for an hour or so then pick up on the subs after its passed the meridian.
Thx for the interest & comments guys. Might catch you at Leyburn in the New Year David
Mark
Bolts_Tweed
15-11-2009, 08:36 PM
Sry Alex - I forgot - the np is 540mm. I am waiting for a wide field corrector so my mosaic frames are overlapping about 1/4 of an image at the moment - and this is cropped (about 1/4 frame top to bottom) to remove some slight vignetting as well.
You would think for a 4 inch Apo that used to retail at nearly 7k from memory until they dropped the price to 5.5k that is built primarily for astrophotography they would include a corrector for large DSLR chips (they say they are built for them)- I would have paid the extra 300 or so instead of waiting now for Big Als crew to get around to sending one. Not a complaint just an observation - really happy with the optics.
M
AlexN
15-11-2009, 08:46 PM
Well, Actually you would expect a scope "designed" for imaging with large sensors (APS-C through to 35mm sensors like the NP 101~NP127) to not need a corrector... The optics are very sharp as you say, but you would think, if they are going to release a scope that claims to be aimed at photographic use, that it would have a large (at least 50mm) corrected imaging circle, with a similar area of full illumination... Take the Tak FSQ106 for example... Similar price to the NP101iis, similar focal length, similar optical configuration, yet the Tak delivers a dead flat field with full illumination over a 35mm sensor without any problems what so ever.. Makes you wonder what Big Al was thinking, doesn't it..
A great result Mark. Interesting to hear the use of deconvolution for such wide field work. Typically the sampling doesn't suit such an activity. You did indicate the application was mild so may not have made a considerable impact. Well done. Looking forward to seeing more.
Bolts_Tweed
15-11-2009, 09:01 PM
Thx Jase
Your tip re colour dodging has made the most difference to this faint stuff I am try to gather at the moment.
I made the MLDB mild - not a lot in this wide field to use it on as you said. I just tried to highlight cloud edges a bit.
M
Bolts_Tweed
15-11-2009, 09:38 PM
Sry to boimbard the forum with posts but I have been talking to dynobolt david off forum about capturing the Witch and need to post this sub as an example for him.
David - this is a 20 min sub - modded 350D, in camera nr on, 800 from a 540 mm Apo refractor from a pertty dark sky site. As I said - a touch red :eyepop:but it isnt too hard to adjust as discussed.
Mark
Hagar
16-11-2009, 09:21 AM
Very nice witch Mark. I found this a hard one to process and make somewhat blue. You have done very well.
Well done
multiweb
16-11-2009, 09:27 AM
Very well done. Colors are great. Smooth as too. :thumbsup:
Bolts_Tweed
16-11-2009, 11:29 AM
Thx Doug & Marc
Ive got to be honest - the smoothness is smoke & mirrors.
The doging & processing for neb enhancement introduced a lot of noise and I didnt have the number of subs to fix it so I used an old trick.
Ran a median filter on the data to smooth it then ran a little (mild) ML decon enhancement on the original and layer masked the sharp stuff through (cloud edges etc) then bought the slightly colour saturated stars over from the original. Worked ok - I suppose but as I said its a bit of smoke and mirrors. Alls fair in love, war and astrophotography.
Mark
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