today's early digital shot M16

[raymo]

Yesterday's offering attracted no attention, so here's another for today. As usual 8" f/5 Newt. 10x 40 secs ISO 1600. This needs viewing at about 50-60% screen.
raymo

[gb44]

Looks more like coma than tracking to me. Elongated stars lower left and upper left pointing towards centre of the pic - versus all elongations in the same direction.

What say you? Needs a coma corrector.

GlennB

[xelasnave]

You always get my attention Raymo I try to comment but sometimes I miss doing so and mean to later but dont get around to it always.
And everyone I am sure looks forward to your photos so just keep them coming.
I suppose you dont have the original subs for any of these..but if you did it wouls surprise you what running them through startools or pixinsite.
There are features that round up stars for example.
But the current image is rather decent in my view and thank you for posting.

Now everyone please post your comments or Raymo will use lack of comments to slack off posting and we cant have that☺.
Alex

[raymo]

Cheers Glenn, yes coma for sure; I only got a CC for that scope years later.


HI, Alex, yes I have the original subs for almost all my stuff. If I wanted to make a silk purse out of a sow's ear I would have tried years ago, but I'm
not interested in trying again to get my head around processing, which is
why I stuck with JPEGS and DSS, no guiding etc.
raymo

[xelasnave]

I know where you are coming from Raymo.
I was all about keeping it simple and then went and got me a narrow band set up...I have still not done one capture by the rules..you know all your filters, darks and flats and darks for the flats☺...but the main reason I did it was to push myself to commit to more than I knew I was capable of...so spent the last two days trying to set up the 80mm rig ..now gone to a 70mm guide scope and a dual finder scope and guide scope mount. ...got the electric focuser working but it has issues with belt falling off..but I dont think in the field it will fall off because the adjustments are minimal between filters and focus correction...but its a start...and honestly my legs have been so bad the last week if not for the pressure to get everything working I think I could have slashed my wrists.

Anyways not suggesting you go Startools but I bet you would be surprised just how good your images would become ( not saying they are not good) but I know from stuff that I re ran thru star tools you would be surprised.

Startools aint hard if you changed your mind and I have no doubt you could do it..look if I can do it you could as you are probably a great deal smarter than me.. heck and you did film photography which is real easy eh...you managed it Startools would be a breeze.
But I suppose the good thing is you show folk starting that one can get excellent results with a relatively simple approach.

Its good that you have your original subs that is both luck and good management.

Its clear here, but being in Sydney and with only 20 degrees of sky I must say I cant get excited...I have no idea where anything is when in Sydney..maybe just switch everything on and surprise myself☺ mmm probably should test the focuser thing I did. .. the belt works but its not aesthetically pleasing☺

Actually I have a remote vacuum cleaner that I will pull down and see if I can use its wheels and belts etc...who needs to vacuum anyways.
Alex

[raymo]

Hi Alex, I assumed that you had the SW motor focus that connects directly to the focuser shaft.
Nah, I'm not interested in trying to improve the pics, and nor are my poor old eyes.
cheers raymo

[Outcast]

I find your images simply stunning Raymo & a source of encouragement in the KISS principal of developing my imaging skills.

Last night I managed a few hours of clear skies & attempted my first polar alignment of my cg5 Adv Gt. I was a bit sloppy with some things, long story....
I then just took some images at different exposure lengths of some bright stars through my piggy back mounted DSLR.

I have a few things to discuss with a mate to get my head around a couple of things then I'll post my procedure, my stuff ups & pics for more analysis & advice. When I get this bit sorted... I'll move along in my journey, one step at a time...

[mynameiscd]

Brilliant shot of the Eagle. You can see the pillars clearly and like Calton said, about using the KISS principal which has been getting you stunning results for years.
Forgot to comment on yesterday's image, just a busy thing on my behalf.
Cheers
Andy

[Startrek]

Great image Raymo
Nice colour, contrast and detail
Yes there is a little bit of coma, but interesting to mention that my 6” f6 produces more coma than your f5 ??
I use Startools through the repair module to reshape my coma affected stars in the off axis areas, does a great job , but you have to mask out the larger stars with diffraction spikes as they end up looking a bit jaggered.
Amazing image with just short subs !!

[raymo]

Cheers Carlton and Andy.

Martin, My 8" collected nearly twice the light that your 6" does.
I'm pretty sure I cropped off much of the coma on this image.
cheers raymo

[Startrek]

Raymo
Gee twice the light gathering capability, fantastic !!
I’m setting up my new 8” f5 on a EQ6-R next week down at my holiday house dark site using a Baader coma corrector and PHD2 guiding etc..Also fitting a heavy duty longer losmandy dovetail bar and tube rings to make the image train rock solid !!!
Can’t wait for some clear nights down there
Cheers

[raymo]

Hi Martin, just square the aperture in inches to get the light gathering ability
relative to a different size scope. 3"x3=9, 4"x4=16, 6"x6=36, 8"x8=64 etc: so 64=1.78x the light of your 36.
Also, I just remembered that your 6" is photographically slower at f/6 than my 8" is at f/5, making the difference even greater.
raymo

[Startrek]

Thanks Raymo
Can I assume that my new 8” f5 will have a wider image field than my existing 6” f6 , so therefore I should be able to capture more whole DSO objects like the Running Chicken Nebula , Rosette Nebula etc ... ??

[raymo]

No, your 6" f/6 has a focal length of 900mm, [6"[150mm]x6=900. Your 8" f/5 has a focal length of 1000mm, 8"[200mm]x5= 1000. So all other things being equal, your 8" will have a F.O.V. 10% narrower than your 6". The longer the focal length, the narrower the F.O.V., 1000mm is 10% longer than 900, so the F.O.V. is 10% narrower. Laboured that point didn't I.
50mm is approx 1x magnification, so your 6" has a prime focus magnification of 900mm ÷ by 50=18x. The 8" has 1000 ÷ by 50=20x.
An 8" f/4 would have a wider F.O.V. than your 6". 8"[200mm]x4 =800mm ÷ 50= 16x. Hope this helps.
raymo

[Startrek]

Sorry
I didn’t know what I was thinking , of course it has a narrower FOV due to focal ratio
Thanks