Markarians Chain wide field

[gypsy (Mick)]

Hi All

Not the best image of this subject but I was amazed by how many galaxies are in there, I was so excited I couldn’t resist posting it

it probably needs a longer exposure time.
but anything much over 30 seconds and over 400mm with the star tracker gets harder.
I took just over 400 subs but only got 206 usable and even then, they are not perfect
decided not to crop this one as there are several other galaxies in the frame such as M99 and M87
happy for any suggestions on how to improve on this next time I have a go at this one

206 subs,30seconds, F6.3, ISO 6400 lens @ 400mm
Nikon D850 with Tamron 150-600 and star tracker 2i

regards mick

[raymo]

Hi Mick, You have actually over exposed this image. Bright galaxies like these don't benefit from longer subs,[or higher ISO]. All the detail in the brighter ones is completely blown out. Try again using 800 or 1600. You also don't need hundreds of subs. Try 10 at 800, and 10 at 1600, and see what you get.
Here's an early try of mine of the Grus Quartet. 10 x 30secs DSLR ISO 1600.
raymo

[gypsy (Mick)]

Thanks Raymo

sounds like less is more with galaxies
i will try exactly that next time
I most likely would have tried longer exposure hahahaha
great advice
thanks again
mick

[astro744]

You may be interested in these at http://www.jburnell.com/Markarians_Chain.html

Top one with Tele Vue NP127is and middle and bottom image with TV-60is.

Enjoy!

[gypsy (Mick)]

Raymo
i tried another stack just using my existing data and only 18 subs (tried 10 but felt the result wasn't as good maybe with lower ISO it will be)
have attached the original for comparison as well
I used my existing master calibration files 50 x Each darks, flats, bias,
so not sure if i should reduce the number of them as well
i also spent a bit more time on the processing

the result is a definite improvement, the cores are not as washed out.
thanks again for the help

I'm doing a few trips this year to dark sky locations (Bortle 1)
so will have another crack at this one with lower ISO settings

Astro744
those are great images with a high bench mark

thanks
mick

[astro744]

Originally Posted by gypsy

...Astro744
those are great images with a high bench mark

thanks
mick

Sure are. Not mine though (I’m only visual) but, I am very impressed at what the TV-60is can do. If you read the last sentence at the bottom of the page, it says 19th magnitude galaxies were captured with it.

[raymo]

Yep, the galaxies are improved, but the cores are still solid white.
raymo