M20 - pushing the 400mm lens a bit!?

[dugnsuz]

Hi all,
Wanted to see what kind of detail I could get out of my 400mm f5.6L lens on M20 (La Triffid!)

Had to crop it into next week ensuring that the stars look like bloated disasters!:( That and the 15min subs!!!

Bit of fun, so be kind!!:lol:

Canon Astro 40D
Canon 400mm f5.6L @ f5.6
17x15min subs (255mins total), iso1600

Also attached a "Murphy's Law" image!!:rolleyes:

High Res (link to repro version)...
http://s327.photobucket.com/albums/k461/doug-robertson/?action=view&current=19c.jpg

Doug

[leon]

Ah well Doug, can't win em all mate, a bit like this one mate, :shrug: from an earlier experience.:lol: :lol:

Leon :thumbsup:

[dugnsuz]

You been raking around at the back of my sock drawer Leon!!??:P

[jase]

Pretty cool Doug! The 400mm looks to be a keeper. I guess thats the downside of going long on subs, you're bound to pick up satellites, planes, cosmic ray hits, etc. Nothing data rejection can't resolve of course. I think your images could do with some more green in them. This will keep the magenta cast at bay. Other than that, top work.

[Ross G]

I really like your photo Doug.

Great colours and lots of sharp detail.

Pretty good for a DSLR and camera lens.

DSLRs and lenses is starting to become my favourite form of astroimaging. So portable and a huge choice of FOVs and filter options.


Thanks.

Ross.

[dugnsuz]

Thanks jase - the 400mm lens has become my weapon of choice. Your advice as always is most appreciated:thumbsup:



+1 on that Ross although I've always got my eye on the elusive FSQ/FLI combo!
Cheers mate.

Doug

[Paul Haese]

Not a bad set of images. Seeing that re-entry image takes me back a couple of years now. What a weird experience it was seeing this live.

I am considering getting a Nikon adapter for the QSI so I can use my 300mm f2.8 lens on it. I like the idea of getting something like this together for trips and doing some more wider field work.

[dugnsuz]

Cheers Paul - just a bit of an experiment really.

That lucky re-entry pic got me on 'Universe Today' - infamy!!

The QSI + lens sounds very nice.
Doug

[steve000]

Thats a fantastic image man. I also have a 400mm f5.6 I look foward to giving it a shot next new moon.

I had a thought the other day, taking a couple of shots in monochrome mode with a colour filter inbetween then merging the images. obviously tough with a lens, but on a 400mm scope quite easy.. whats your opinion on this. an attempt to get better colour reproduction

[dugnsuz]

Cheers Steve - the 400mm f5.6L is a great lens for astro due to the minimal number (7) of lens elements it uses to get a nice flat, colour-corrected field.

Monochrome mode on the DSLR isn't the same as true monochrome I'm afraid as the camera just produces a B+W version of the RGB image. The bayer matrix filter used to produce an RGB image is still in place on the sensor unlike a mono ccd camera...
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/4601648/Main/4598730

Doug:thumbsup:

[rcheshire]

With Pixinsight you might be able to reject those trails out of the image. It has come up very well otherwise.

[dugnsuz]

Thanks Rowland - I'm going to try a repro of this image over the weekend with particular attention on the bloated stars.
Doug

[dugnsuz]

REPRO...

Changed orientation/framing and tried to de-bloat stars

http://s327.photobucket.com/albums/k461/doug-robertson/?action=view&current=19c.jpg

:thumbsup:

[Craig_L]

Hi Doug,

Reckon that's a nice improvement over the previous version. Those stars seem to have tightenned up nicely.

Had a go at reprocessing some of my old images of this target but was overcome by the noise of my uncooled DSLR and gave up.


Craig

[midnight]

Some good colour in there Doug as well as the detail is quite good too!

Congrats - It seems a really good combination.

Darrin...

[dugnsuz]

Cheers Craig and Darrin,
But, I don't think I'll be pushing the lens with 100% crops in future.
Still, it's nice to see the resolving power of the lens.
Doug:thumbsup: