View Full Version here: : First go at Astrophotography - All advice most welcome
29-03-2012, 01:31 PM
I was testing a nice 120 ED 7.5 refractor last night, with my Nikon D700 attached, and although I'm a professional photographer- this is my first go at this genre, and it's great fun!
All feedback is welcome positive or negative. I'm only going to learn by getting constructive criticism from all you experts out there.
This is a single 60 sec capture - iso 640. There are 9 more similar images to stack, but I have a mac, not a PC. Can anyone recommend some Mac friendly stacking software? It would be fun to see how much more info I can get from these images.
Can anyone recommend links to good image processing tutorials?
29-03-2012, 01:41 PM
I wish my first go had looked that good.
If you have a mac, try nebulosity out and see if you like it. You can try before you buy, and it is cross-platform.
It is a great starter program.
Some other useful apps there as well.
There is also StarTools which I am just learning now, it looks good so far.
The image looks a bit overprocessed, a bit heavy on saturation and sharpening, but a cracker of a result for a first go. You will be able to bring the noise down a bit with the stacking and pull some more detail out.
A 7.5 means long exposures, might look into a reducer for that scope.
What was it mounted on?
I'd go to ISO 800 on the D700.
29-03-2012, 02:07 PM
Not bad at all for a first crack.
First of all unlike photography, astrophotography processing is a little bit different as the colour reproduction generally is spread over so little of the histogram its not that the data isn't there.
As for your image the tracking looks alright, but the colours are a long way off, the black point is clipped. Use something like Photoshop to inspect the raw image (not processed). Use Levels to bring the histogram into line The RGB channels should line up pretty much and that will give you basic colour balance.
With your black point and white points don't go too over the top. stay clear of the tail of the histogram as thats where your faint data sits, cut this the background goes nice and black which is bad :(
Ive found Deep sky stacker a great tool for handling large raw bayer DSLR images its computer friendly on resources. Nebulosity is a decent capture tool, but so is Backyard EOS, and a number of other ones as for cross platform. Well i got cluey :) I run with a little eeepc and there for you have no issues with getting programs to sing together Mac although it works on some it can be a nightmare on others... whats a few hundred for a dedicated Telescope/Camera/mount controller that you can log into via something like Team viewer? very handy.
29-03-2012, 08:04 PM
You are miles ahead of my first attempt at M42. :thumbsup:
Keep the photos coming.
29-03-2012, 11:54 PM
If I was going to spend a few hundred I'd get a 2GHz 2nd hand macbook, you can run OSX, Windows, Linux, and it has a reasonable amount of grunt
30-03-2012, 11:41 AM
Peter i use the KISS theory! when your 400km from the nearest street light the last thing you want to be stuffing around with is multiple OS's :) You may be happy with that set up, I am not I have seen very skilled people fail epically when they don't have resources around them! :)
30-03-2012, 06:34 PM
Hey thanks guys, appreciate the tips and feedback, most helpful!
Not sure if Nebulosity supports my Nikon, it only lists Canon Dslr's on the specs, but will download a trial version and see, if it works as I really prefer to stay on the mac if at all possible. I'll try some of the others as well : )
The 'scope is on an EQ5 goto mount. Hey Peter, what's a reducer?
30-03-2012, 06:47 PM
Multiple OS's give you redundancy, if your windows craps out, you can boot something else. I have never had multiple OSs cause any problem in the field.
30-03-2012, 08:11 PM
Whats the point of having a macbook at night? No one is around to see you using it.
30-03-2012, 08:21 PM
:rofl:Better duck for cover....INCOMING.
30-03-2012, 08:47 PM
Hey AC, great to see you on here. To over simplify it, a reducer effectively reduces the focal length of the scope so (to use my celestron as an example) with the .63 reducer that you can get for it mine becomes an F6.3 with the wider field and reduced exposure times that go with it compared to its original F10
31-03-2012, 01:44 PM
This is the Same image reprocessed per suggestions from BMitchell82 & Poita. Somewhat more subtle now. Interesting - there's a fine balance required between getting a technically vs. aesthetically good result.
Goes to show how steep a learning curve I have ahead : )
When I can get my hands on the gear again, I'll do some more - looking forward to it!
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