M81 and M82

[ashworthacca]

Hi guys, last night I managed to grab a couple of hours trying to fine tune my imaging processes and finally managed to use LiveView on my Canon 1000d to focus and also find and sync alignment stars. That is an achievement in itself for me so I was well pleased.

Anyway, my back garden gives restricted viewing of the nights sky and all the lovely objects to the east are blocked by my house.

This is only my second attempt at imaging and I thought I'd grab another shot at M81/M82. Used APT to run 22x120 secs lights and 20x120 secs darks. Stacked and processed in Nebulosity 2 finished off with GradientXterminator, Neat Image and a selective sharpen in Photoshop.

My monitors are not calibrated, it looks lighter on my laptop but dark on my works monitor.

It obviously needs plenty more time spending on it to get more detail but I'm happy with it so far.

EDIT: I revisited the original and tried to remove the blue and get a little more detail. Background too dark?? False colours in stars or have I just brought out their true colours?

[jgs001]

Looks like a good start Martin, I'm no expert on this side of it, but it looks like you have more details in the spiral you might be able to dig out... As you say, more time will help a lot and make a big difference.

[ashworthacca]

Looks like a good start Martin, I'm no expert on this side of it, but it looks like you have more details in the spiral you might be able to dig out... As you say, more time will help a lot and make a big difference.

Thanks John, I can see a little detail in the spiral but I'm not sure how to get more out:D. I've processed this image for about 3 hours this morning and gone back to the beginning a couple of times. I need to do a little more reading and playing with the processing side me thinks.

Thanks again John

[russ]

That's very nice Martin. Very smooth, really nice pin point stars and you have retained the star colours too. As John says, you maybe able to extract some more detail from the sprial arms but if you reprocess it, don't push it too far. See so many images that are pushed too far and they lose their natural feel.

[jgs001]

Ah now, that processing system sounds very familiar we must have gone to the same school...

Just had a very quick play... and slapped it with a curve that looked a bit like...

And there's more there... just be more gentle than this curve, repeat as needed, try to keep the background the same as it is now... that's why the lower point is there... Working with the original data you should be able to get more out of it... start with the TIF for the current save.

Good luck.

[ashworthacca]

That's very nice Martin. Very smooth, really nice pin point stars and you have retained the star colours too. As John says, you maybe able to extract some more detail from the sprial arms but if you reprocess it, don't push it too far. See so many images that are pushed too far and they lose their natural feel.

Thanks Russ, I could see the detail when I was processing it but I did like you say, pushed it too far, created noise and went back to the drawing board when I'd created a mess.

[ashworthacca]

Ah now, that processing system sounds very familiar we must have gone to the same school...

Just had a very quick play... and slapped it with a curve that looked a bit like...

And there's more there... just be more gentle than this curve, repeat as needed, try to keep the background the same as it is now... that's why the lower point is there... Working with the original data you should be able to get more out of it... start with the TIF for the current save.

Good luck.

Brilliant, thanks again John.......I'll have a bash when I get home from work later.

[russ]

Good luck Martin.

[cloudbuster]

lovely image Martin...well done!

[ashworthacca]

Good luck Martin.

lovely image Martin...well done!

Thanks guys:)

[EA2007]

Good target, especially with the really light skies we have with the sun not setting until 21:30 or so.

I would maybe leave off the darks, you have quite a lot! maybe try only half that amount.

What ISO were you shooting at?

[ashworthacca]

Good target, especially with the really light skies we have with the sun not setting until 21:30 or so.

I would maybe leave off the darks, you have quite a lot! maybe try only half that amount.

What ISO were you shooting at?

Ahh, thanks for the tip. Not really sure what I'm doing with darks etc so any advice more than welcome. I used ISO 800.

[ollypenrice]

Wow, sharp. Look at the dust lane splitting the cigar! Well done.

On my monitor a bit too blue?

Olly

[ashworthacca]

Wow, sharp. Look at the dust lane splitting the cigar! Well done.

On my monitor a bit too blue?

Olly

Thanks Olly.

My monitors need calibrating:D It doesn't look too blue on my laptop which I use for processing but it does on my works monitor.

Looks like I need to calibrate the laptop screen.....another learning curve.

[george7378]

Great! That's a beautiful combimation - I remember spending a lot of time with those two earlier this year, and would love to see them again.

[ashworthacca]

Great! That's a beautiful combimation - I remember spending a lot of time with those two earlier this year, and would love to see them again.

Thanks George. They are a great target for me at the moment. The sky is quite restricted in my back garden but these are in view pretty much all night.

[george7378]

Right - I bet they are circumpolar from 53 degrees north too. I am yet to pick out that lovely dust lane on M82 - I'm sure I'll get it eventually

[ashworthacca]

I've just had another play using only 10 Darks and applying the curve suggested by John. The crop is slightly different. I'm not sure whether doing this has made it look a little more blotchy to the dark sky???

I think I need to get my Synguider connected and increase the exposure for each sub to get more detail.

[russ]

Hi Martin, you've certainly got more detail, especially in M81. But i think you are right, it's at the expense of the background sky. It's a hard thing getting the balance right. I always struggled too.

[george7378]

That said - I wouldn't be disappointed with what you have there!

[adamsp123]

For only the 2nd go that is impressive indeed! Well done.

[ashworthacca]

Hi Martin, you've certainly got more detail, especially in M81. But i think you are right, it's at the expense of the background sky. It's a hard thing getting the balance right. I always struggled too.

Any tips for getting detail and keeping the sky from blotching happily received:D

That said - I wouldn't be disappointed with what you have there!

Thanks again George.

For only the 2nd go that is impressive indeed! Well done.

Thanks Pete, I'm at the very bottom of a very steep learning curve.

[EA2007]

Hey again,

Hmm, the second one shows the arms of the spiral in M81 more clearly.

As for the blotching...are you processing the images before stacking them? I know that if I tamper with RAW's or JPEG's before stacking then I get the blotching effect.

I wasn't criticising before by saying that you had too many darks : ) was just saying that most people only use a few to counteract any rogue hot pixels or lighter frames. Its personal preference.

[adamsp123]

I dunno about only using a few darks, I thought it was the other way around?, too few darks and you can increase the noise, I use 30+ from a darks library for a master dark plus about 30 flats.

To get more out of the image you probably need more subs, that does work! BTW I use kappa sigma clipping for the lights in DSS.

[ashworthacca]

Hey again,

Hmm, the second one shows the arms of the spiral in M81 more clearly.

As for the blotching...are you processing the images before stacking them? I know that if I tamper with RAW's or JPEG's before stacking then I get the blotching effect.

I wasn't criticising before by saying that you had too many darks : ) was just saying that most people only use a few to counteract any rogue hot pixels or lighter frames. Its personal preference.

I didn't take your post as a criticism, I welcome any comments and help as I honestly don't know what I'm doing.

I don't do anything with the raw files before they are processed in Nebulosity so not sure what I did to generate the blotchy background second time round.