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lensman57

Ready to be Slated, please feel free.

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Hi to all you good people of the forum,

Here are my first two serious attempts at DSO imaging using my new atik 428EX OSC. What I have done so far in the last 3 months or so, using a modded Canon 1000d has not really tickled my fancy so please blame the operator and not the equipment. I took the opportunity of having a couple of "clear hazy nights" by Manchester standards to use the Atik, to be fair both nights were far from clear, haze, high thin clouds and a lot of moisture in the air were the order of the day and as I live less than 3 miles from Manchester airport I am used to adversity and LP filters now. One image is M27 and the other from M101, SW 80 ED Blue @F7.5, 50 mm guidescope with an ASI 120MC as a guide camera and PHD guiding with GPUSB, the mount is SW EQ5 pro, hardly exotic stuff. I have a window of opportunity for imaging between 11.45 pm and 3.15 am at present, dependind on which part of the sky I am aiming at. My back garden is very small with tall trees to the west and the north and houses to the east and the south. M101 is a stack of 23 subs of 450s each @ -2.5c, the M27 is a stack of 25 subs of 240s each , darks, flats and bias frames were stacked in DSS and processed in StarTools and a bit of tweaking in CS2. Any advice and guidance is greatly appreciated as long as it doesn't mean spending any more money, so here it goes.

Regards,

A.G

post-28808-0-66949800-1373403465_thumb.j

post-28808-0-63888400-1373403585_thumb.j

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I'd probably say that high hazy cloud was your worst problem.

M27 looks alright but somethings made it look like its been taken through misshapen glass.

So I would give it another go on a clear night.

I can usually tell now if the high cloud is too thick but i do tend to be very picky and won't

Image if i can see any.

Sent from my GT-P5110 using Tapatalk 2

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As ncjunk said the hazy really put a downer on those images. But its a good start and can tell its taking in good data.

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Well I have to say that I reckon those both look pretty good and way better than my first CCD images!

The hazy has probably impacted on the quality of the subs. You can overcome this to some extent with more subs, but as it is you might find that you get a better result by dialling back the processing a tad. The focus and guiding look good to my eyes so just hold the stretch back a bit and I think it would look more natural.

These are both good images, though, IMO.

Ian

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Well I have to say that I reckon those both look pretty good and way better than my first CCD images!

The hazy has probably impacted on the quality of the subs. You can overcome this to some extent with more subs, but as it is you might find that you get a better result by dialling back the processing a tad. The focus and guiding look good to my eyes so just hold the stretch back a bit and I think it would look more natural.

These are both good images, though, IMO.

Ian

Thank you all very much for your comments, I am bit surprised at how weak the M101 image was to be honest as I gave it well over 2.5 hours of exposure with just an LP filter in place, I guess under circumstances it is the best that I could manage. Your point about processing is quite right, I have just started using StarTools and the controls are bit geeky for my simple mind but I am sure that in time I will master it. I have already done a more tame version of the M27, but the M101 is more of a challenge even though the data is there somewhere.

Regards,

A.G

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Thank you all very much for your comments, I am bit surprised at how weak the M101 image was to be honest as I gave it well over 2.5 hours of exposure with just an LP filter in place, I guess under circumstances it is the best that I could manage. Your point about processing is quite right, I have just started using StarTools and the controls are bit geeky for my simple mind but I am sure that in time I will master it. I have already done a more tame version of the M27, but the M101 is more of a challenge even though the data is there somewhere.

Regards,

A.G

Well keep it up. I must say that I bought StarTools but I just can't get on with it... hope you have better luck as from some of the images posted on here it is clearly very capable software....

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No slating.

Sky conditions apart there are a couple of things I'd advise.

You have dark rings around the stars which probably come from a sharpening routine like Deconvolution or Unsharp Mask. I'd advise you to exclude the stars and the background sky or faint parts of the image from any sharpening because all you'll get are artefacts and noise. Ps makes this easy with a variety of selection tools but the easiest way for starters is to create a copy layer of the unsharpened image and sharpen the bottom layer. The use the eraser on the top layer to erase the parts you'd like to sharpen. Simple! (Conversly you can use the same idea to noise reduce one layer and use the eraser to remove the noise reduction from regions of good sharp detail.)

Also, watch your histogram;

Black%20clipping.-L.jpg

In the bottom image the imager is on the point of black clipping the data. He has moved the black point slider too far to the right. When he clicks to apply this, all the faint data seen on the left of the upper histogram will be gone forever, leaving a jet black sky without the subtle and faint outer reaches of the object. Try to leave a little bit of horizontal line on the left as in the upper image.

You've made a cracking start. No slating here!

Olly

http://ollypenrice.s...39556&k=FGgG233

Edited by ollypenrice
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Thank you Olly for your detailed reply, all points taken and digested. The deconvolution is indeed what produced the black halos around the stars even thought I had masked the stars, will try your method instead. Hoping for a clear night and a sound mind.

Many thanks and regards,

A.G

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Well I think they're nice images particularly M27 :) I don't think I did as well as that with a DSLR :D

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Pictures look OK to me, I'm only an observer so I always appreciate any astro pictures on here.

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Pictures look OK to me, I'm only an observer so I always appreciate any astro pictures on here.

Many, many thanks to all of you. I have a steep learning curve ahead of me but I like this hobby, I am not going to get stressed and will try and learn and enjoy it for as long as I can. Now if anyone needs advice for doing some old fashioned photography I would be glad to be of help, particularly with the wet stuff. Does anyone know what these are anymore? LOL, !!!

Regards and thanks to all,

A.G

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Nice going and congrats on getting the Atik up and running!

If at anytime you need any help with StarTools, do contact me. Happy to do a personal tutorial, specific to your data if you wish. In that case just share a typical night's worth through a service like Dropbox and we'll do our best to take the mystery out of working with ST for you! :)

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Nice going and congrats on getting the Atik up and running!

If at anytime you need any help with StarTools, do contact me. Happy to do a personal tutorial, specific to your data if you wish. In that case just share a typical night's worth through a service like Dropbox and we'll do our best to take the mystery out of working with ST for you! :)

Hi Ivo,

Manty thanks for your comments and support, I may take up your offer of help if it is ok with you. I have opened a drop box account and will leave the two captures in the shared folder once I get back from work tommorow morning, some hobby for a restaurant manager.

Many Thanks and Regards,

A.G

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Don't be hard on yourself, these are good first images. The 'easy' part is in the data capture, get good guiding and good focus and then I think that's the most important part of the capture process sorted.

Processing on the other hand is something of a mystery! What works on one image doesn't work on another, somthing that you've learnt to deal with one issue doesn't work on different data - A real minefield. Olly makes good points about clipping the black point. This is certainly something that I have been guilty of, trying to hide a less than perfect background for example, but it's worth trying to sort out the problem rather than just darken it into submission!!

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