This is different

I'm curious to get feedback on this shot of IC 5070, which is an emission nebula shining at 656.3 nanometers (red) and has a temperature of 10'000 K.

48minutes at ISO 400, 60mm refractor f/6.2, 7D

Cool shot, I like it.

Unfortunately, I don't think you will get a ton of critique here...have you posted this in the astro forums??

This is a terrible image...the crop is all wrong...image should be rotated and flipped...I could go on but it's obvious that I pulling your leg.
I like it just the way it is...your skill makes me green with envy.

Two questions: Where is it? How do you know how hot it is?
Otherwise... what Chauncey said!

Thanks for the feed-back! I did post this in the astronomy section and I did get comments - the idea was to see what those who don't do Astrophoto think about this.

Image should have been cropped more tightly, N America nebula is cut, and it's true that there's no scale or correction for orientation. No flip though - I use a refractor for deep sky, so true image is ok

Where it is - well... It's far away (photons in my picture are 1800 years old) and can be found in constellation Cygnus. Google told me it's 10000 K hot

ecce_lex wrote in post #16460169
Thanks for the feed-back! I did post this in the astronomy section and I did get comments - the idea was to see what those who don't do Astrophoto think about this.

Image should have been cropped more tightly, N America nebula is cut, and it's true that there's no scale or correction for orientation. No flip though - I use a refractor for deep sky, so true image is ok

Where it is - well... It's far away (photons in my picture are 1800 years old) and can be found in constellation Cygnus. Google told me it's 10000 K hot

For those wondering, 1800 light years is about 10,581,525,671,730,494 miles, or ten quadrillion, five hundred eighty-one trillion, five hundred twenty-five billion, six hundred seventy-one million, seven hundred thirty thousand, four hundred ninety-four miles!!!

davidmtml wrote in post #16460810
For those wondering, 1800 light years is about 10,581,525,671,730,494 miles, or ten quadrillion, five hundred eighty-one trillion, five hundred twenty-five billion, six hundred seventy-one million, seven hundred thirty thousand, four hundred ninety-four miles!!!

So you can't get there on a single tank of gas!

Nicely detailed image for being so far away and shooting through earths atmosphere but I am curious about the green tint on most of the stars. Is that normal?

It's so far away that when those photons were emitted by ionised hydrogen atoms, romans were roaming around crucifying people :P

The green tint - that's because I suck at post processing and am unable to compensate for the two green pixels I have for each red and blue on the bayer matrix of my camera.

There's little to no chromatic aberration in the instrument (sexy fluorite glass that focuses all wavelengths in the same plane) so there's only myself to blame.

Coming back to the distance - it blows me away to know that a bunch of tiny photons spent all this time travelling towards my camera. And now they're forever (well... "forever") on the almighty internet.

While I don't understand a lot of what you are saying here (I saw the big numbers and thought we had entered a discussion of the US national debt) I do appreciate the skill involved in this shot. I don't have those skills but I do appreciate them.

Love it the way it is. The explanation just makes it all the more fascinating. It is an amazing universe no matter how you look at it.

Oh my goodness, I love it! Astrophotography is incredibly intriguing, although I don't know enough about it to give any useful feedback.
Amazing what the camera can pick up that our eyes cannot see - well caught!

Hm - have you considered maybe a couple of steps more to the right?

am i right in thinking your exposure was 48 mins? if so .....i know this is a dumb question before i ask it but why havent they moved? if i expose for justa few seconds maybe a minute or two the stars move and create a blurred image.
thanks
Bill

billozz wrote in post #16461374
am i right in thinking your exposure was 48 mins? if so .....i know this is a dumb question before i ask it but why havent they moved? if i expose for justa few seconds maybe a minute or two the stars move and create a blurred image.
thanks
Bill

You need to either take many shorter exposures and merge.

Or have a tracking mount that slowly rotates the camera with the same speed as the earth rotates.

i see what you mean obviously if the camera tracks with the earth rotation then you can expose for longer and get a better image

Many thanks for your comments.

The skill is purely technical, no "eye" is required: the subject is very pretty in itself and you don't have much choice in framing or angle .

You are both right concerning exposure - the mount tracks the sky and several exposures are taken. High class astrophoto involves a dedicated instrument that follows a star and gives instructions to the mount in real time to keep a steady tracking and correct for mechanical imperfections.

This photo is a stack of 120s unitary frames, not guided, under a very nice dark sky.