Quote:
Originally Posted by h0ughy
OK did you take flats and bias's?
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I don't even know what a
bias is or how to take it. I'm not going to bother with flats until I get the lights and darks right. I believe (perhaps wrongly?) that taking and calibrating flats will only offer slight improvement to my image, compared to the rest of the things I need to get right first, which will improve the image by much more.
Quote:
Originally Posted by Dennis
The background looks a little too dull or grey on my LCD display.
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Thanks Dennis, I agree - my processing leaves a lot to be desired. The dull grey background is indicative of the sky that night but I probably could've done more to process it out, or reduce it. Looking at it now (on a proper screen) I could've adjusted the black point more, but I did all the processing on my laptop screen while on the plane over to Perth. In hindsight I should've waited.
Quote:
Originally Posted by jase
Mike, a fine achievement. I think you've highlighted your deficiencies in original post and agree with them. The longer the integration time the easier the data is to work with and the smoother final image will be. ...and yes, there is a lot more to DSO processing than levels and curves, but don't underestimate the power of these two tools. They play a major part in what you want to display to the viewer. Histograms are your friend, know how they respond to different techniques will ensure you are making the most out of your data. There are of course many more linear and non-linear stretching tools that are suited to different objects. Look forward to seeing more as you develop your style/processing work flow.
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Thanks Jase - I appreciate your comments and look forward to your constructive criticism. And you're right - I need to work on my processing workflow - at the moment it's too rushed and I'm not paying enough careful attention to the data I've got. But with better data, the motivation will be there to do it better
Quote:
Originally Posted by tornado33
Well done, great to see youre getting into DSO imaging now |
Thanks Scott - DSO imaging is a different beast, that's for sure. I'm not sure i'll ever take the time needed to do it really well like you and other guys here do. If I've only got a spare hour, you can capture a great planetary image if the seeing is excellent. But in DSO imaging, you need to spend much longer to get a good image. I also need more "tools" to do it properly but maybe I'll build them up over time.
Quote:
Originally Posted by Bassnut
Well Mike, im going in hard here, cause I know you can take it ;-).
Not good, and you have told us EXACTLY why already, thats why I recon within a few weeks or mths you will absolutely cream this DSO stuff.
You are one of the best on the planet for planetary (sic) and you are a perfectionist, this is a very short stepping stone to DSO nirvana, stop mucking around dude ;-).
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Thanks Fred, I appreciate your honest feedback and I can take it. I know what I need to do to get better at this DSO imaging, it's just a matter of the right tools and techniques, and more time.
I'm happy with this as my first image, but certainly not happy with it as a galaxy image. There's a lot to do!
Quote:
Originally Posted by rat156
A couple of tips for you;
Try to not saturate you stars when hitting the picture with levels. All your stars are white, very white.
Your grey level is too white, about 90% is what I work with most of the time.
Use layers to get the colour right in one pic and the detail in another, then recombine, you can even fake a luminance from the RGB data.
Don't be tempted to go too long in you exposures, 2 mins is about all I can get without skyglow dominating, even from relatively dark skies.
Lastly, stop pissing about with the DSLR, get a mono CCD, you've got the LRGB thing going in the planetary stuff.
Why don't you use the DMK as a guider?
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Thanks for your tips and feedback, Stuart.
You're right about the stars.. There was very little colour in the galaxy and pushing the saturation brought a little colour into the galaxy but most likely to the detriment of the stars. I need to do more masking and selective processing. I really haven't taken the time to learn DSO image processing properly yet. Once I am capturing enough quality data then that'll motivate me to improve my processing routines.
I'll be persisting with the DSLR though - I already have the mono DMK but i'm not planning on using it for DSO imaging, and I can't afford to buy a mono deep space camera.
I do plan on using the DMK to guide with, but I need to set up a guide scope first. I've got a cheapo 80mm refractor which I'll use (with the DMK) to guide the ED80, but I need to get the right mountings to set them up side by side. Guiding is definitely one of the next steps for me.
Quote:
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Originally Posted by nandopg;258626
If you don't mind, a couple of suggestions:
1- Use ImagePlus to calibrate, align and stack your images. [B
Always[/B] calibrate with darks, flats and bias frames.
2- Use an off-axis device for image composition and coarse focus. I use one carried by Taurus Technologies ( www.taurus-tech.com). In my opinion this is a must have accessory.
3- For fine focusing I use DSLR Focus. It is much better than the focus resource present in ImagePlus.
4- Fine tune your polar alignment making sure that the mounting is able to track a star for at least 40 minutes. Use a cross hairs eyepiece for that. I use in this case the star's drift method.
5- Don't use ASA 1600 in your camera, use ASA 800 at most. |
Hi Fernando, thanks for your comments and suggestions.
1- I tried using IP to calibrate but my dark frames ended up with pixel spots all over the place and when subtracted from the lights, left dark pixel spots. I'm not sure what I did wrong, but I'll give it a go next time.
2- The Taurus device looks interesting - did you get the Mini Tracker or the Tracker III? Do you have to replace it with the camera afterwards?
3- I don't have DSLRFocus - what makes it better than what is in ImagesPlus?
4- Yes, definitely something I need to work on. I've been very lazy and haven't spent any time getting alignment right.
5- I would've liked to use 800, but wanted to capture as much light as possible given my shorter exposures. I was hoping I'd be able to avg the frames (instead of adding) if I got enough exposure at ISO1600, but 90s just wasn't enough.
Quote:
Originally Posted by glenc
Nice shot Mike. You should be able to get the galaxy 253 and the globular 288 in the same 2 degree wide field.
Caroline Herschel found 253 and it was the first galaxy I ever saw with a telescope.
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Thanks Glen, i'll definitely work on the composition next time.
Thanks all for your comments, tips and suggestions. I appreciate your feedback.
