New to imaging - direction of next step

[Brymstone]

I'm quite new to imaging and I have to say that the learning curve is astoundingly steep. There is the getting the image side of things and then the whole processing side which seems to be an art of it's own. I've finally got an image that I'm pretty happy with, much better than my previous efforts. What I'm looking for is some suggestions of what I need "more of" to improve it. Sorry that it's yet another M42 image but it's an easy target to practice and try stuff on.

I know that there are a lot of areas that will provide improvement but because I've got a limited amount of sky time and time to process. I'm looking for what would give me the best bang for the buck improvement. Basically, what's the next best direction or thing to do to improve the image. Think the 80/20 rule, 80% of the results are gotten with 20% of the effort.

This is what I started with, it's kind of green because of the light pollution filter but the stack came out ok.

I stacked 9 x 30s images with DSS and tweaked with the settings to get the image below.

So when I look at other people's pictures I see them being a lot of darker backgrounds and more detail. A few of the things I know I can do are:

More subs - I see anything from 1 to like 100 subs so I don't know what's really needed per the 80/20 rule

Dark frames - I get so little time to use the telescope that I don't really want to sit there and just take darks, but I will if it gives a good return.

Flat frames - I'll have to build a light box or something if I need to do these, not high on my immediate list 

longer subs - This has been a real issue for me, when I get up to the 60s range things get really washed out, so I don't know how people get 5 min subs, dark site?

Dark site - is it as simple as I need to travel to a dark site for imaging?

post processing - I seem to have the best results so far tweaking DSS but I know a lot of people use PS but I've tried it and honestly just don't know my way around it enough to use it.

Any thoughts and suggestions would be appreciated. It's all a learning curve to me just not sure where to focus next.

Thanks,

Chris

[zcdawson]

Can you tell us what your equipment is?

[Brymstone]

Sorry, I should have mentioned the equipment. I don't have a lot of experience with any piece of the kit so I'm still figuring some stuff out.  It seems like I get 1-2 days a month to get out with the scope and find that I need to buy something else to bring the images to the next level. The LPS filter was the last piece and these images were the first I've taken with it, and they're the best I've gotten to date.

Skywatcher 10" CF Quattro F4

AZ-EQ6 GT Synscan GPS mount

Orion Starshoot autoguider

Optolong V4 CCD LPS filter

Backyard EOS to aquire images

PHD2 to guide

Thanks,

Chris

[Brymstone]

And the imaging camera is a Canon T1I / 500 with no modifications.

[kalasinman]

Is this a crop? I seem to see coma on the left and stars better on the right. I guess I missed it, is the camera a Canon?

Darks can be automated with BYEOS. Just set up and pop off for a nap. With longer subs, you wouldn't have to stretch as much and more detail. Maybe try 240 sec? I like to go 25-30 subs, stack in DSS, then press register again, then press cancel and select the best subs and re-stack. Try a range of ISO.

[wxsatuser]

So when I look at other people's pictures I see them being a lot of darker backgrounds and more detail. A few of the things I know I can do are:

More subs - I see anything from 1 to like 100 subs so I don't know what's really needed per the 80/20 rule

Dark frames - I get so little time to use the telescope that I don't really want to sit there and just take darks, but I will if it gives a good return.

Flat frames - I'll have to build a light box or something if I need to do these, not high on my immediate list 

longer subs - This has been a real issue for me, when I get up to the 60s range things get really washed out, so I don't know how people get 5 min subs, dark site?

Dark site - is it as simple as I need to travel to a dark site for imaging?

post processing - I seem to have the best results so far tweaking DSS but I know a lot of people use PS but I've tried it and honestly just don't know my way around it enough to use it.

Any thoughts and suggestions would be appreciated. It's all a learning curve to me just not sure where to focus next.

Thanks,

Chris

Decent LP filter will get longer subs.

Depending on sky conditions, I have moderate LP, I can do up to 10 minute subs.

5 minutes at f/4 is about the norm here with a Canon 60Da.

[Brymstone]

Kalasinman:

It's not cropped and I did use the F4 Coma corrector that they say is made for my telescope. It has helped a lot with the coma but it doesn't mean that there might still be some there or I've wondered about collimation. I did just notice the other night that there was dew forming on the primary mirror so I made a little heater to help deal with it. I can't remember if I did that before or after taking these pictures though so I'm wondering if that coma you see might be dew getting in the way?

For the Darks I thought that they needed to be taken at the same temperature as the lights meaning that you had to take them at the same time as you're doing the lights? This would of course cut my imaging time in half which is why I hadn't wanted to do them unless it would make a big difference.

For the longer duration subs, I've been really trying to get them longer which is the reason for purchasing half the kit! However, it seems no matter what I do they get really over exposed at even 60s let alone longer. I thought the light pollution filter would solve the issue and it has helped but it's still not to the extent that people have said it would. I live relatively close to the coast so I'm wondering if we just have a lot of water vapour in the air and the light pollution is diffracting off the vapour?

For the ISO setting, I'm finding 800 is about the max at 30s and I've gone as low as 100 for 60s. I'm a little baffled as to how people get 5 min subs at 1600 iso. In the back of my mind I keep wondering if it's as simple as needing to drive an hour out of town to get some darkness. From the last session I started finding dew on the mirrors and CC so I'll pay a lot more attention to that next time and hopefully I'll get some longer subs.

[Brymstone]

Blue straggler:

These images were taken with a filter on, hence the greenish blue tinge to everything. I'm actually amazed that DSS managed to remove the blue tinge while stacking, I didn't do it, the stacking process got rid of it. I've ordered the IDAS p2 filter as well since everyone speaks so highly of it but the current filter blocks out a LOT of stuff and I still can't seem to get the extended subs.

Here is the spectrum on the current filter.

[kalasinman]

Ahh, I see. I'm new at this too. Maybe we can help each other. I have a fast Newtonian, an f/5. I am told that the sweet spot for collimation shrinks dramatically between f/5 and f/4. You remove the comma corrector before collimating? What do you use to collimate with? When I purchased my scope I passed on an f/4 because of criticality of collimation. I wish I had a high power eye piece. A proper star test should be the last step and a star test needs that.

Heating the primary mirror can be counter productive, as it can cause air currents which in turn cause distortion. If you have a dew issue, try making a dew shield. I made on out of some sparkly project paper (all I caould find). Rolled it around the aperture with wider at the outer opening, and taped it. Slips on and off, but doesn't fall off.

Darks should be taken at the approximate same temp as the lights. Don't waste imaging time. Take your subs, then program BYEOS for your darks, and retire.

Your scope is big and fast. I think for bright objects like M42. try 400 or even 200. I'm mostly dealing with reasonably dark skies...when the farmers aren't burning rice stubble or sugar cane ;-) . There is no substitute for dark skies. Filters can only remove data.

Your filter

Hutech IDAS LPS

[swag72]

If I can just go back to your original thread, where you say that you want to get 80% of the result with 20% of the effort - I think that you need to be a little clearer about your expectations with regards to your images. If you look on the imaging forum, what sort of images are you aspiring to? I ask as if you are looking at getting to the quality of the best, you need to give it 100% of everything to get there.

Your initial image looks pretty good for starters and certainly gives you a good base to build on. But how far do you want to go? What do you want to achieve?

Flats are an easy win - Get them done and right and they will make a significant difference with little effort.

More subs will definitely help - How many you take and how far you want to go really is a personal preference really - I take long subs and tend to do relatively few, but still rack up many hours of imaging time per completed image.

[lensman57]

Hi Chris,

You have done well for starters. One thing that you need to accept in AP is that there are no short cuts. To get decent images a lot of effort in acquiring the data and then in processing has to be put in. If it is said that to calibrate the subs correctly to give the data best chance of being separated from the noise, Bias, Darks and Flats are required and in large enough numbers then that is what you need to take correctly and apply correctly to the subs so that you can process them correctly and extract max detail. There is no substitute for a lot of data and this means long integration times, subject to a minimum length of sub how you get there is up to you but  most of the successful imagers such as Sarah prefer long subs and long integration times to build the signal. An image with strong signal stands a better chance of being processed more aggressively without triggering the dreaded noise.

Regards,

A.G

[kalasinman]

If aspiring to image as well as Sara, or A.G 20% of effort won't get close. 100% and years of learning might.

[Brymstone]

I should be a little clearer on the whole 80/20 thing. I do aspire to the incredible images I've seen here and at Astrobin and I know this is a hobby that will take many years to master, as I said before the learning curve is astounding. Because I'm so new I'm just not sure where I should be focusing my efforts. From reading the forums I can tell that all the flats, bias, longer duration subs, post processing, etc. etc. will help and be required for those images but what I don't have a feel for is how to prioritize these efforts. By looking at the pictures you can probably tell where I'm at imaging wise  so I'm trying to figure out if I should be focusing on troubleshooting why I can't get longer subs or start working on a light box? Eventually it will all get done but I'd rather take the path that gets me a 10% improvement to the image rather than the 1% improvement path.

[kalasinman]

Obviously you have an interest in DSOs as that's where you started. OK, so maybe lay aside the concerns about risk/reward and just start following suggestions you get here.

Remove the obstructions that hinder results with the kit you have now.

You have to walk before you can run.

Collimation will be a challenge with such a fast scope. Get that nailed first.

Start a calibration library so you can organize the Bias, Darks, and Flats by ISO temp and exposure time.

Darks are simple start using them.

Bias is also very easy, perhaps the easiest calibration frame.

You don't need a light box to take flats. 2 layers of white T shirt and aim at a clear morning sky, or even that uniform grey sky that coastal BC gets.

Polar alignment good?

Put aside the coma corrector for just a bit and post some images without it. That will make things easier to evaluate.

I think you are getting distracted by concerns about LP at this point. If you get the above items done and dusted, your images will improve, lacking that you will not progress.

[zcdawson]

I'm also new to AP. My answer was to throw money at it. At about 7k into it I'm learning that nothing replaces experience. I spent 9 hrs last night to have a bunch of images that are going to need alot of processing.

To start i would spend just a little time every chance you get on the calibration frames. You can build a library of exposure lengths for the darks. Make a master flat (works as long as you don't change your image train and pay attention to the timing of your thread on attachments). Bias are easy.

Me, I have a cooled CCD so i don't need darks or bias most of the time. I made a flat box and found that the 5 minutes of good sky is easier for the flats. My problem is at f/2 focus is a pain even with an autofocuser. Polar alignment was a pain to figure out but i think I've got that down. Now I just have to figure out how to maximize the equipment i have because the wife is eyeballing the account.

[zcdawson]

I'm also new to AP. My answer was to throw money at it. At about 7k into it I'm learning that nothing replaces experience. I spent 9 hrs last night to have a bunch of images that are going to need alot of processing.

To start i would spend just a little time every chance you get on the calibration frames. You can build a library of exposure lengths for the darks. Make a master flat (works as long as you don't change your image train and pay attention to the timing of your thread on attachments). Bias are easy.

Me, I have a cooled CCD so i don't need darks or bias most of the time. I made a flat box and found that the 5 minutes of good sky is easier for the flats. My problem is at f/2 focus is a pain even with an autofocuser. Polar alignment was a pain to figure out but i think I've got that down. Now I just have to figure out how to maximize the equipment i have because the wife is eyeballing the account.

[dph1nm]

The biggest difference anything  made to my imaging was when I started taking flats. And I just use the twilight sky - it works pretty well.

NigelM