Rosette Lum with ST8300 + ED127 - Page 2

AlexN · #21 14-01-2010, 07:28 PM

Frank, From what I saw, I'd assume the ED127 will have a flat field over the 5D, I only say this because I had pinpoint stars even through the off axis guider, where as on my TMB/LOMO 80mm F/6 the stars in the OAG are fairly warped... The ED127 seems to have a nice flat field..

Congrats on the G11 too!

Should be a real beast...

Best of luck with the new rig mate, I'm sure you'll do well with it..

Thanks for the great responses again everyone... All very much appreciated..

Octane (Humayun) · #22 14-01-2010, 07:38 PM

Frank,

I've tried the combination, and, whilst the resolution is mind-blowing, with the standard ED127 focuser, there is a horrible amount of vignetting, that even critical flats can't really fix.

What you'll end up with is the almost the same field that a 1.6x crop sensor will give you, really.

H

gregbradley · #23 14-01-2010, 07:41 PM

Great shot Alex. That shows an amazing amount of detail there. I like how you captured the "twister" so nicely.

Slight amount of sag from somewhere with bottom left stars a bit elongated. Did you use a 2 inch nosepiece or a screw on adapter?
A screw on would probably handle that minor issue. Something has a small amount of slop in it, not much just a tad.

The 8300 is the best chip in the current crop of chips around that size I reckon. There is a 10100 but only in colour which is a shame.

How much do ED127's cost? China is flexing its muscle now eh? and soon it will be the Tak of China emerging.

Greg.

AlexN · #24 14-01-2010, 08:11 PM

Thanks for that H.. I remember you posting the Eta Carine shot that you took with yours... If you upgraded the ED127 to a bigger focuser you might get better results.

Greg - Thanks mate.. Yes, the focuser on the ED127 didn't like the 2.8kgs of camera/cfw/flattener/OAG/guider that I had hanging out of the focuser.. and there was a touch of slop... I was using 2" push fit connectors, I would like full threaded connections, however the focuser on the ED127, and on my 80/480 do not have threads standard... Thats definitely an upside of the Tak focusers... everything is thread on, and very rigid..

I was very happy with the twister as well.. Selective sharpening did a lot to bring that and some of the other detail up nicely..

I agree the KAF-8300 is as good as it gets at the moment, great pixel size, great QE, a decent sized sensor and relatively low noise (compared to a KAI-11002M) They are fantastic... The 10100 looks like it would be amazing too, except it being colour only is a real shame... However, its the only colour camera that can do binned colour images.. You can bin the sensor 2x2 and still get a colour image... This does it wonders, as you could use the camera with 9.25 micron pixels binned 2x2 and get a colour image, then on nights of magnificent seeing, go back to bin 1x1 with 4.75 micron pixels... I don't remember exactly, but I don't think Kodak even make a monochrome version of the 10100.. That said, the KAF-8300 rules the roost, especially for these wider field scopes..

I asked how much the ED127 cost, and it was around $1150 USD including delivery.. At that price, I think the scope is amongst the best bang for buck we've seen from an APO telescope... colour correction is great, its hellishly sharp... I have a comparison image that I'll post up later today... HST vs Mikes AP152 vs ED127 on the fickle finger in Eta Carine... The results really speak for themselves.. while the ED127 is no Astrophysics, its definitely a hell of a lot of scope for the money..

Cheers.
Alex.

Garyh · #25 14-01-2010, 08:31 PM

That is one cracker shot Alex!
Very impressed with what you have done with the 127 and your new camera!
Gary

AlexN · #26 14-01-2010, 08:38 PM

Thanks Gary, The 127 + KAF-8300 make a good pair... I might get a chance this weekend to test the 8300 in the 80/480.. Hopefully I can get something with similar detail, although I might have to shoot at something I'd hoped to avoid this season... Good old M42..

Hopefully not, but maybe..

RobF (Rob) · #27 14-01-2010, 09:02 PM

Wow! Stunning pic Alex. You can really stick your head into that one and have a look around

I had to look twice - thought you must have been shooting Ha.....

AlexN · #28 14-01-2010, 09:12 PM

From what I understand Rob, a lot of the real fine wispy detail in there is actually OIII and SII wavelength light.. in an RGB shot, the rosette looks like a predominantly Ha region, as most of it appears as red. however in narrowband images, the OIII channel is very strong too, and SII shows a fair bit of detail as well...

I bet you're dying to get that QHY9 pointed at the rosette!!

CoolhandJo (Paul) · #29 14-01-2010, 09:36 PM

I agree, the detail is definately there! Looks very promising

RobF (Rob) · #30 14-01-2010, 10:57 PM

Quote:

Originally Posted by AlexN

I bet you're dying to get that QHY9 pointed at the rosette!!

You bet!!

I did run off some 30secs subs Sat night while I was trying out my "L Plates", but they won't come anywhere near those glorious 10min subs you've got there. You and Peter sure got the 127Apo singing!

Paul Haese · #31 15-01-2010, 04:34 PM

Alex, nice shot. Looking forward to the colour.

What program are you using to stack your images? I cannot see much noise in your image.

What temperature are you running at? I usually work at -15c to maintain a good amount of head room.

DavidU (Dave) · #32 15-01-2010, 04:46 PM

Alex, I'm still waiting to hear from Gillman.

AlexN · #33 15-01-2010, 04:56 PM

Paul - I'm using DSS to stack the images, 10 darks were subtracted from each light frame before the lights were stacked...

The image was taken at -10C.. Some selective noise reduction was used to clean up the image here and there, other areas were selectively sharpened... It took quite a long time to process actually.. Trying to get the detail to come out without incurring the wrath of the noise gods...

No worries David, Keep me apprised..

pmrid (Peter) · #34 15-01-2010, 05:30 PM

Quote:

Originally Posted by Octane

Frank,

I've tried the combination, and, whilst the resolution is mind-blowing, with the standard ED127 focuser, there is a horrible amount of vignetting, that even critical flats can't really fix.

What you'll end up with is the almost the same field that a 1.6x crop sensor will give you, really.

H

Hi Hamuyan,

mind if I butt in? The Ed127 Alex used is mine so I claim some connection to this thread. I am planning to put a modd'd 20D on this scope and seeing your response to Frank about his 5D wondered why it might be that the focuser would cause vignetting? This ED127 is fitted with what Gilman called (als sold as) their upgraded focuser for astroimaging. Make any difference to the vignetting?

Peter

AlexN · #35 15-01-2010, 05:55 PM

Peter - The 5D has a sensor 1.6x the size of the 20D or the QHY8 that you're used to... 35mm diagonal. And given that the focuser tube is 2" (50mm round) I dare say the inside of the focuser tube would clip the light cone somewhat. If you were to put a 3" FT focuser on it you may.. MAY get rid of the vignetting.. but I don't know that for sure obviously.

I will say though, with a chip the size of the KAF-8300, you do not need to worry about that. I did not take flats and did not notice any vignetting in the images..

spearo (Frank) · #36 15-01-2010, 07:10 PM

Great detail
well done
frank

Bassnut (Fred) · #37 15-01-2010, 07:14 PM

The detail is just stunning Alex, very impressive.

Omaroo (Chris Malikoff) · #38 15-01-2010, 08:46 PM

Damn you Alex - you've done it now. I've ordered one too. I've sent the email...

Thanks very much....

Rigel003 (Graeme) · #39 15-01-2010, 09:57 PM

I've just caught up with this photo, Alex. Absolutely amazing! Great capture and processing. You must be very pleased with the new camera. Looking forward to more.

Octane (Humayun) · #40 16-01-2010, 12:38 AM

Peter,

Alex beat me to the reply. He's spot on.

I also have the "advanced" focuser. I think all they mean by that is that it can carry a larger load and is rotating. That's about it, I think. I'm saving my pennies for a 2.5" Moonlite. I'm not too fussed if that won't illuminate the entire field on a 35mm frame, as, I have plans to jump into the CCD world. So, with an APS-C size chip of the 8300, which is very similar to a standard 1.6x crop Canon, you don't have to worry about vignetting. Feel free to refer to the images I've posted lately taken with the ED127 and 40D. No vignetting.

H