Pleiades AP140 @ F5.6

gregbradley · #1 10-01-2011, 01:22 PM

I had a dream run of weather at my dark site over the Christmas break. I had 10 out of 12 nights clear and 1 night clear for several hours.

It seems to me that the western side of the Great Dividing Range (leeward side) is the drier side and the usual weather pattern is that even if its cloudy during the day it very often clears after dusk when the air cools a bit and the clouds are reabsorbed so you often get completely cloudless nights. So if you are looking to find a nice location for dark imaging in NSW then I suggest the western side of the mountains. I have seen it time and time again. I left Sydney and it was completely overcast only to find completely cloudless skies all night there.

Seeing was variable with 3 nights of excellent seeing and several where it was OK to poor.

I managed to image the Pleiades on the night that had cloud come in at about 2:00 am giving me about 4 hours of available imaging time (dark is about 10pm now) .

AstroPhysics 140 scope with specialised reducer/corrector giving F5.6. This is no ordinary reducer as it gives .75X reduction but it also corrects the field so its pinpoint stars corner to corner on a 16803 chip.

A remarkable optical achievement. Such a great scope.

I wanted to bring out the background dust and nebulosity and managed to do so to some degree. As usual more hours would add but its at a good point here.

LRGB 30 40 20 40 minutes FLI Proline 16803, Astrodon Gen 11 filters and Tak NJP mount at my dark site observatory at Bigga NSW where the wild goats and goannas roam and the occassional Kangaroo says hello.

http://upload.pbase.com/gregbradley/...17600/original

Here is a darker version of the same area with less background showing but better contrast:

http://www.pbase.com/gregbradley/image/131722349

Here's a photo of the setup:

http://www.pbase.com/gregbradley/image/131718019/large

Greg.

iceman (Mike) · #2 10-01-2011, 01:26 PM

Wow, that's beautiful. Incredible work Greg!

TrevorW · #3 10-01-2011, 01:32 PM

very nice Greg, plenty of detail, but bright may need to tone it back a bit IMO personal taste

gregbradley · #4 10-01-2011, 01:37 PM

Quote:

Originally Posted by iceman

Wow, that's beautiful. Incredible work Greg!

Thanks Mike. I was happy to be able to bring out the background dust given the exposure time. The dark skies certainly help.

Quote:

Originally Posted by TrevorW

very nice Greg, plenty of detail, but bright may need to tone it back a bit IMO personal taste

Thanks Trev. Yes it is pretty bright. But hey, I already pulled it back!! hehe. If I pull it back more I lose the background dust as I have already looked at that. So its a compromise really.

Greg.

h0ughy (David) · #5 10-01-2011, 02:40 PM

WOW, yes it is bright but it is beautiful. you did well with the weather.

in a word - Awesome

strongmanmike (Michael) · #6 10-01-2011, 03:14 PM

Really lovely Image for a quicky Greg.

The brightness looks ok to me...but it would be interesting to see a dimmed version with more highlights, just for interest to compare. The short exposure time looks to have necessitated a bit of smoothing especially in the outer regions..?

...Aaarggllll... the that setup looks veeery sexy...

..I'm off to be alone..?...with mine

Mike

DavidTrap (David) · #7 10-01-2011, 03:32 PM

Very impressive Greg, but on my calibrated monitor, I also feel that it is too bright. Would something like "Shadow-Highlights" be able to bring it back a bit - that is currently my favourite photoshop tool, I've been using it quite a bit processing my holiday pics, unfortunately not astronomical shots (apart from the moon visible in the sunrise & sunset shots).

I have my name down on the waiting list for the AP140... Let's see what the world holds in 10+yrs time. My hunch is that it will be too heavy for my mount and imaging gear (limit 20kg), so I might have to settle for the 130 (on the list for that too!), or upgrade the mount...

I got a Christmas card from AP in the post today. I presume you get one in the year after you buy something from them. Wonder if you they send you one while you're on the waiting list???

DT

gregbradley · #8 10-01-2011, 04:30 PM

Quote:

Originally Posted by h0ughy

WOW, yes it is bright but it is beautiful. you did well with the weather.

in a word - Awesome

I couldn't believe my luck with the weather. After so many cloudy nights here in Sydney and driving into clear skies it seemed surreal.

Quote:

Originally Posted by strongmanmike

Really lovely Image for a quicky Greg.

The brightness looks ok to me...but it would be interesting to see a dimmed version with more highlights, just for interest to compare. The short exposure time looks to have necessitated a bit of smoothing especially in the outer regions..?

...Aaarggllll... the that setup looks veeery sexy...

..I'm off to be alone..?...with mine

Mike

A darker version here:

http://www.pbase.com/gregbradley/image/131722349

It doesn't show the background dust so much but gives better contrast. Always a compromise one way or the other unless you get megadata.

Quote:

Originally Posted by DavidTrap

Very impressive Greg, but on my calibrated monitor, I also feel that it is too bright. Would something like "Shadow-Highlights" be able to bring it back a bit - that is currently my favourite photoshop tool, I've been using it quite a bit processing my holiday pics, unfortunately not astronomical shots (apart from the moon visible in the sunrise & sunset shots).

I have my name down on the waiting list for the AP140... Let's see what the world holds in 10+yrs time. My hunch is that it will be too heavy for my mount and imaging gear (limit 20kg), so I might have to settle for the 130 (on the list for that too!), or upgrade the mount...

I got a Christmas card from AP in the post today. I presume you get one in the year after you buy something from them. Wonder if you they send you one while you're on the waiting list???

DT

Thanks David. I posted a darker version reined in a bit more and it gives more contrast.

I got this scope 2nd hand (it was 3 months old) so no Christmas card for me! I have my name down for a Riccardi Honders but no notification yet.

The scope is quite chunky and heavier than you'd expect for the size.
With the camera, guide scope and filter wheel plus rings and finder scope it would be well over 20kg.

Did you know the tube is made from a solid piece of aluminium and hollowed out? The tube has baffles machined into it. Amazing eh?

Greg.

DavidTrap (David) · #9 10-01-2011, 05:19 PM

Thanks Greg for the info. I thought it would be well over 20kg, but the 130 would probably be doable.

I much prefer your darker version. I had a quick fiddle with your first image using Shadow-Highlights and achieved something similar. I didn't think you lost too much background dust.

Cheers
DT

strongmanmike (Michael) · #10 10-01-2011, 05:20 PM

Quote:

Originally Posted by gregbradley

I have my name down for a Riccardi Honders but no notification yet. Greg.

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Alchemy (Clive) · #11 10-01-2011, 05:38 PM

Stunning image Greg, you've done really well, as for too bright

works for me, they are very bright stars after all. Plenty of extended nebulosity too.

As for the clear skies.... Might as well be on mars given I don't consider my gear portable. Currently raining here... All week too.

spearo (Frank) · #12 10-01-2011, 05:43 PM

Greg,
love the dark version
frank

multiweb (Marc) · #13 10-01-2011, 06:18 PM

A truly magic picture Greg! I'm in awe.

Love it!

Hagar (Doug) · #14 10-01-2011, 06:25 PM

Lovely image Greg. A quicky, my God you have squeesed every bit of gas and dust in the area into this image. What are the single dif spikes on your stars? ?Shutter maybe.?
Very impressive image.

gregbradley · #15 10-01-2011, 06:36 PM

Quote:

Originally Posted by spearo

Greg,
love the dark version
frank

Thanks Frank. Yes I like it too now.

Quote:

Originally Posted by multiweb

A truly magic picture Greg! I'm in awe.

Love it!

Wow, thanks Humi.

Quote:

Originally Posted by Hagar

Lovely image Greg. A quicky, my God you have squeesed every bit of gas and dust in the area into this image. What are the single dif spikes on your stars? ?Shutter maybe.?
Very impressive image.

Thanks, I try to get the most out of it. The diff spikes? I am not sure where they come from. The camera for sure but what I don't know.
One person said it was the screws in the filter wheel and if you blacken them they go. I blackened mine with a permanent marker and it made no difference. I don't think the Microline does this and I saw an image with a Microline 16803 and no spikes so something to do with the Proline.
It doesn't bother me particularly but it would be good to isolate the cause.

Greg.

Paul Haese · #16 10-01-2011, 06:37 PM

Superb image Greg and I reckon probably you best yet. Detail is great colour and contrast all lovely in my opinion.

gregbradley · #17 10-01-2011, 06:40 PM

Quote:

Originally Posted by Paul Haese

Superb image Greg and I reckon probably you best yet. Detail is great colour and contrast all lovely in my opinion.

Why thanks Paul for the nice words.

Greg.

renormalised (Carl) · #18 10-01-2011, 06:52 PM

Both great piccies, Greg. Ace setup too with the AP

pgc hunter · #19 10-01-2011, 07:01 PM

wow look at all that nebulosity! Definately the best image of the Pleiades I've seen.

gregbradley · #20 10-01-2011, 07:39 PM

Quote:

Originally Posted by renormalised

Both great piccies, Greg. Ace setup too with the AP

Thanks for that. I hope you are OK up there with the flood problems in Qld.

Quote:

Originally Posted by pgc hunter

wow look at all that nebulosity! Definately the best image of the Pleiades I've seen.

Gee thank you, high praise.

Greg.