Widefield M51...

[tooth_dr]

Pretty much straight out of APP ( @Xiga big thanks to Ciaran for help on using this programme), with just a little adjustment in PS/GIMP.  106x300s ISO800, with 50% moon, ED80

I will try to process it later with new flats.  I used existing flats but three dust bunnies have shifted so it made things worse, hence the crop.   I seem to have picked up a few faint background galaxies, the guiding and star sizes shapes etc seems better than I've done to date.  If I do a meridian flip, do the flats and bias automatically flip too?

 

Any pointers welcome

 

Thanks

Adam

[DaveS]

The flats and bias will flip too, as they don't depend on where the 'scope is pointing.

Good image by the way. What's your sky like? Did you use any kind of LP filter?

[alacant]

1 hour ago, tooth_dr said:

Any pointers welcome

Nope, love it; contrast and colour nice. And yeah, if you've still the camera attached, new flat frames will nail it.

But hey, 300s with a half moon, that's amazing, Last night we got no more than 180s at m81. So gave up:( Trying to work out if m51 is further from the moon...

Cheers and clear skies

[tooth_dr]

44 minutes ago, DaveS said:

The flats and bias will flip too, as they don't depend on where the 'scope is pointing.

Good image by the way. What's your sky like? Did you use any kind of LP filter?

Thanks Dave. I didn’t use any LP filters. I’m not sure how to quantitatively evaluate my skies, but what makes you ask about it?

[tooth_dr]

@swag72 I’ve just tagged you Sara to say thanks for telling me how to stack subs from different nights 

[tooth_dr]

6 minutes ago, alacant said:

Nope, love it; contrast and colour nice. And yeah, if you've still the camera attached, new flat frames will nail it.

But hey, 300s with a half moon, that's amazing, Last night we got no more than 180s at m81. So gave up:( Trying to work out if m51 is further from the moon...

Cheers and clear skies

Thanks! It looks a bit redder on my phone now than on my work monitor. Maybe 300s was too much!

[DaveS]

11 minutes ago, tooth_dr said:

Thanks Dave. I didn’t use any LP filters. I’m not sure how to quantitatively evaluate my skies, but what makes you ask about it?

I'm looking at the faint stuff around M51, as well as the faint galaxies in the background. There's no way I'd get those from where I live. Have a look on this map

https://www.lightpollutionmap.info/#zoom=9&lat=6598280&lon=-263593&layers=B0FFFTFFFF

Move to your location, and it'll give a fairly good reading of your SQI

[Craney]

 106 x 5 mins !!!!!!    my goodness.... that's commitment to an image.   But I suppose you need that to get the 'dust / gas ' detail off of the interaction region.

Good work.

[tooth_dr]

1 minute ago, Craney said:

 106 x 5 mins !!!!!!    my goodness.... that's commitment to an image.   But I suppose you need that to get the 'dust / gas ' detail off of the interaction region.

Good work.

Sean Thanks! 1 night, using my dual ED80.  58 subs from each scope, dropped a few with clouds, stacked the rest.

[tooth_dr]

7 minutes ago, DaveS said:

I'm looking at the faint stuff around M51, as well as the faint galaxies in the background. There's no way I'd get those from where I live. Have a look on this map

https://www.lightpollutionmap.info/#zoom=9&lat=6598280&lon=-263593&layers=B0FFFTFFFF

Move to your location, and it'll give a fairly good reading of your SQI

Thanks for that link, very useful.  I've posted below:

Zenith sky brightness information

SQM 21.47 mag./arc sec2

Brightness 0.278 mcd/m2

Artif. bright. 107 μcd/m2

Ratio 0.627

Bortle class 4

Elevation 213 meters

[swag72]

1 hour ago, tooth_dr said:

@swag72 I’ve just tagged you Sara to say thanks for telling me how to stack subs from different nights 

Glad it helped!! I may do a video tutorial for it, but it was quite simple to explain!

[DaveS]

1 hour ago, tooth_dr said:

Thanks for that link, very useful.  I've posted below:

Zenith sky brightness information

SQM 21.47 mag./arc sec2

Brightness 0.278 mcd/m2

Artif. bright. 107 μcd/m2

Ratio 0.627

Bortle class 4

Elevation 213 meters

That's pretty good, probably as much as most of us can hope for, though there are some with darker skies, Olly for one.

[swag72]

1 hour ago, tooth_dr said:

Thanks for that link, very useful.  I've posted below:

Zenith sky brightness information

SQM 21.47 mag./arc sec2

Brightness 0.278 mcd/m2

Artif. bright. 107 μcd/m2

Ratio 0.627

Bortle class 4

Elevation 213 meters

Wow you have skies that most of us could only dream about  

[tooth_dr]

11 minutes ago, DaveS said:

That's pretty good, probably as much as most of us can hope for, though there are some with darker skies, Olly for one.

I checked the readings at the new ‘dark site’ which is near my house (6 miles away) and it is as follows:

 

[DaveS]

Argh! Rub it in why don't you .

[DaveS]

*sigh*

This is what the map says I have

I think they're being optimistic

Zenith sky brightness information

 

SQM

18.70 mag./arc sec2

Brightness

3.56 mcd/m2

Artif. bright.

3390 μcd/m2

Ratio

19.8

Bortle

class 7

Elevation

45 meters

 

 

[celestron8g8]

Love the WF capture ! You got several companion galaxies also . That ED80 has great WF images . Thanks for sharing . 

[nightskystargazer]

Adam,

Very nice M-51  .

CS,KLU,

Thanks  .

Tom

 

[Xiga]

Very nice Adam, glad you got APP to stack them all for you. This looks great, especially as it's had virtually no post-processing. Plenty of faint fuzzies in there too, and once you get the dust bunnies sorted this will be top notch!

A quick bit of APP advice, the first two things to do once you have your stack is to run the 'Remove Light Pollution' tool (which deals with gradients) and then the 'Calibrate Star Colors' tool (avoid putting any boxes over areas of genuine nebulosity. stars are ok). They are usually very quick tools to use, but boy are they effective! From this point on, you just have to save the file (with or without a DDP stretch) and then move over to using PS. 

Another tip, while APP's DDP stretching capabilities are impressive, at the moment it is not a fully 'colour-preserving' stretch (it's on Mabula's to-do list). It still retains the colour pretty well, but for something like a Galaxy image, i would try using sharkmelley's excellent PS Arcsinh stretching technique instead, just to see if it improves things (bonus tip, record as an action to REALLY speed it up). 

I also like the 'Camera Raw' filter in PS for dealing with colour noise. A small amount (max 20%) of the colour slider under noise reduction can work wonders on background colour noise. Just be sure to use a star mask first, in case it accidentally picks up any tiny faint stars as noise by mistake. 

[tooth_dr]

6 hours ago, Xiga said:

Very nice Adam, glad you got APP to stack them all for you. This looks great, especially as it's had virtually no post-processing. Plenty of faint fuzzies in there too, and once you get the dust bunnies sorted this will be top notch!

A quick bit of APP advice, the first two things to do once you have your stack is to run the 'Remove Light Pollution' tool (which deals with gradients) and then the 'Calibrate Star Colors' tool (avoid putting any boxes over areas of genuine nebulosity. stars are ok). They are usually very quick tools to use, but boy are they effective! From this point on, you just have to save the file (with or without a DDP stretch) and then move over to using PS. 

Another tip, while APP's DDP stretching capabilities are impressive, at the moment it is not a fully 'colour-preserving' stretch (it's on Mabula's to-do list). It still retains the colour pretty well, but for something like a Galaxy image, i would try using sharkmelley's excellent PS Arcsinh stretching technique instead, just to see if it improves things (bonus tip, record as an action to REALLY speed it up). 

I also like the 'Camera Raw' filter in PS for dealing with colour noise. A small amount (max 20%) of the colour slider under noise reduction can work wonders on background colour noise. Just be sure to use a star mask first, in case it accidentally picks up any tiny faint stars as noise by mistake. 

Ciaran, thanks for the very detailed reply.  Tried to get sky flats last night but it was mizzly. Might give it a go with an iPad over the end of the scope. 

[Xiga]

34 minutes ago, tooth_dr said:

Ciaran, thanks for the very detailed reply.  Tried to get sky flats last night but it was mizzly. Might give it a go with an iPad over the end of the scope. 

That's how I do mine. Ipad resting on the end of the dew shield, with a sheet of opal in between to act as a diffuser 

[tooth_dr]

Despite taking new flats, still having trouble.  Cropped and reprocessed:

 

[Rodd]

I like the original one better--the black point in the last is a bit low and you are losing some faintbstuff.  Nice amount of detail for a small object--very nice capture.

Rodd

[Allinthehead]

I have to say i like the last version better. The first looks like the background has been over stretched. Nice work.

[tooth_dr]

Thanks guys. Version one wasn’t really processed. Just the DPP that APP does!

The last version I tried to process it. The laptop I use has a weird screen, I can hardly get the brightness or colour right on it.