PDA

View Full Version here: : First light for canon 300mm lens - ANTARES


DJScotty
02-04-2016, 10:20 AM
Hi all. This is a 4 hour pretty much uncropped luminance (CLS filter) shot of the Antares region, shot through my canon 75-300mm lens at 300mm at f8. 10 minute subs.

I have just completed the contraption to hold the lens, as detailed here... http://www.iceinspace.com.au/forum/showthread.php?p=1240074#post124007 4

Posting so that you wonderful people can critique and find things that I can't see to improve the image.

Anyway, thanks for looking.

Cheers,

DJ Scotty :D

Atmos
02-04-2016, 10:38 AM
Looking quite good Scott, bet it looks better in the high res over the 200kb :)

Out of curiosity, are the diffraction spikes around the stars caused by the lens iris or the camera shutter?

Andy01
02-04-2016, 10:40 AM
Well that contraption is not going to win any beauty contests but I salute your engineering skills and perseverance, well done!

I look forward to seeing what you can image in full colour next :)

DJScotty
02-04-2016, 10:58 AM
It doesn't really!
I am assuming it would be the lens iris as the Atik doesn't have a shutter. Thanks Colin :thumbsup:

DJScotty
02-04-2016, 10:59 AM
Maybe 9th runner up out of 10 things...

HaRGB of Antares is in the pipeline!

Thanks Andy :thumbsup:

AstroJason
03-04-2016, 08:32 AM
Looks good Scott. The diffraction spikes are def from stopping the lens down to f/8. I really like the look of diffraction spikes in images. Have you tried imaging with the lens at f/5.6 at 300mm?

DJScotty
03-04-2016, 08:42 AM
Thanks Jason.
No I haven't but I will have to experiment.
Cheers

Ross G
03-04-2016, 09:55 AM
Nice looking capture Scott.

Good detail and looks sharp right across the frame.

Your invention looks pretty amazing as well!

I have just started experimenting with a Nikon 300mm lens on a QHY9.
The 300mm focal length gives a nice FOV for a lot of objects.

Looking forward to seeing more photos.

Good luck.
Ross.

DJScotty
03-04-2016, 11:38 AM
Thanks Ross for the kind words
May I ask you how you go about focusing your lens?

Slawomir
03-04-2016, 01:06 PM
Awesome work Scott :thumbsup:

rustigsmed
03-04-2016, 02:38 PM
looking good Scottie, hanging to see how it turns out when the colour arrives!

Rusty

DJScotty
03-04-2016, 03:20 PM
Thanks very much gentlemen.
Let's hope this weather holds out for 3 more nights

Ross G
03-04-2016, 08:55 PM
Hi Scott,

I have an adapter of sorts that has a T2 thread on one side to attach to the QHY9 camera and a Nikon bayonet at the other end.
The back focus distance of Nikon lenses is about 45mm. The chip to front distance of the QHY9 is about 19mm and the adapter makes up the rest, allowing me to focus with the lens' focusing ring.

Focusing is quite fiddly but ones achieved remains constant all night.

Thanks.
Ross.

DJScotty
04-04-2016, 01:50 PM
Aaaah ok. Thanks for that. Sounds simple