Photographing the ISS

[MarkS]

I took this at 5:20 this afternoon.  It's my first ever attempt at the ISS.  I can't believe my luck - it actually worked!
I manually swung the C11 on the EQ6 mount and had the Nikon D70 attached.  It's the best of 7 shots.


Details:  C11 with F6.3 reducer.  ISO 1000.  Shutter 1/1000s.  This is a crop of the original with no rescaling.

According to http://www.heavens-above.com/ it was magnitude -2.4 over Sidcup

[Mike]

Wow!! That's a fantastic image Mark. The detail is incredible. Well done. How did you focus?

[MarkS]

I focused on the moon earlier - it's the only thing in the sky that's easy to focus on.

[Rick]

Wow! Great shot!

[Tony G]

Well done Mark, excellent clear image.
Its amazing how many more objects and different items the society is imaging in the past couple of years and how it is encouraging many others to start imaging and others to venture even further into the realms of astrophotography.

Tony G

[MarkS]

It's mind boggling to think that this is flying 210 miles above our heads. 
So from Sidcup it's like trying to photograph an object as far away as Devon! 

Next time I'll take the F6.3 reducer off.  That'll give an image of 60x60 pixels instead of 40x40.

[Ian]

It's mind boggling to think that this is flying 210 miles above our heads. 
So from Sidcup it's like trying to photograph an object as far away as Devon! 

I've never thought of it like that. We get so used to looking at objects lightyears away it becomes meaningless. That's just about the closest object we're likely to try to image and when you say it's as close as Devon, that puts it into an unusual perspective.

excellent image by the way. Without the focal reducer, do you think you'll be able to see the astronauts inside?

[Mike]

Mark,

Any chance of posting the original proportioned image up please so we can get an idea of how much this thing filled the FOV? Thanks.

[MarkS]

Sure, I'll post it later tonight - it's 3000x2000 pixels of blackness with a misshapen dot somewhat off-centre!

Each pixel is roughly 0.9 arcsec ( though I haven't done the exact calculation for the D70 on the C11+ F6.3 reducer).   
So, in the sky, it has the same overall dimension as the width of Saturn's rings.

[Mike]

So in other words it's TINY !!

I am amazed the NASA guys haven't got images of the ISS using those huge satellite tracking platforms they've got.

[JohnP]

According to Ron Wodsaki it's .93 arcsec/pixel - FOV is 35x41 arcmins... see below - I also shown picture of Saturn in FOV - it's the tiny little dot in the middle. Mark I think you did a great job on capturing this...



John.

[Mike]

I guess it makes aiming teh scope a bit easier though. Imagine trying to track it manually if it filled the FOV?!?! 

[MarkS]

If you want the full frame, here it is (but horribly compressed):
http://homepage.ntlworld.com/the_shelleys/photos/ISS_fullframe.jpg

It's very similar to what John calculated with Ron Wodaski's calculator.

I'll put all 7 images into a single montage later this evening.

[MarkS]

Here are all 7 images taken over a period of 30 seconds - the good and the bad. 



The first was taken at its highest altitude (70deg) because I spent the first 30 seconds fumbling to line it up in the finderscope.  Next time I'll align the EQ6 axis as vertically as possible so it's more like an alt-az mount - this will make it far easier for hand tracking.

All were taken at ISO 1000 & shutter 1/1000sec - there's no time to adjust settings!

[Mike]

Very impressive Mark. Some of the best ive; seen. You should send them in to NASA - they might put them on APOD!

I can't wait to see your attempt at the higher magnification.