Cygnus NAN Canon 24-105mm f4L test 105mm

[Psychobilly]

Finally got a chance to point the Canon 24-105mm f4L IS USM at the sky last night .. conditions weren't brilliant with smeared contraisl and cloud so I only have 26x60s ISO400 of useable unguided subs (EQ3-Pro PA'd with Polarscope and just left to track (no star alignment) from the BCF modified 1000D fitted with the Hutech IDAS P2 MFA filter...

The 240-105mm f4L is a parafocal zoom and works fine on the unmodified 500D but on the modified 100D with the additional inbody filter this is no longer the case.. At 105mm focus is pretty close to the infinity mark on the lens but at 24mm best focus is at around the 5m mark similar things happen with 70-200mm f4L as well...

Anyway decide to shoot low ISO 1 min subs wide open and see what happened I focussed with Liveview as I still havent got round to designign and makng a mask for this lens yet......and I wanted a computer free night lastnight so didnt use APT with its FWHM autofocusing..

Here's Quick process of the result... 26x60s ISO 400 Lights, 24 EL Panel Flats , 24 Bias NO DARKS.. Thrown into DSS then CS3...

Pity I didn't have more than 3 useable 120s subs or any 180s subs due to drifting cloud

I Still need to test it at 24mm and do the same for the 70-200 f4L but this lens will hopefully be my MW weapon of choice in a few weeks time...

Thanks for looking...

Peter...

[Beyond_Vision]

Looks good to the corners and the focus looks spot on Pete

Regards

Kevin

[CGolder]

stunning image

[ashworthacca]

Peter, that's a cracker and the lens looks to be very sharp all the way to the edges. Looking forward to see how you get on with the 70-200.

[Psychobilly]

Thanks the data is too shallow to push had another 2 1/2 hours of 120s and 180s subs but only about 5 frames were totally cloud free

No chance last night clouded out and more cloud and rain at the moment... I really hope it performs around 24mm as well there is a bit of coma in the corners on the highres image but not bad for a zoom wide open...

I really want to get the 3 lenses tested before I hopefully get to play with the Milkyway... it was takign to long at 50mm last year...

[AndyUK]

Looks like you have a really good lens there (and focus is spot on!).... and even I can easily pick out the NA and Pelican nebulae! Nice image Peter...!

[Psychobilly]

The Outlier (Kappa Sigma) stacked one with all the cloudy frames in is better instead of 26 mins of clear this has 26 mins of clear and another 50 of patrially cloudy frames added...

[AndyUK]

That's even better... Nice one Peter!

[Tim]

Great result Peter, really like that.

[Coco]

Lovely image Peter, as you say its quite low at the moment but you have done well with keeping gradients controlled..

Thats a nice lens, L lenses are infectious

.

[Psychobilly]

Thanks..

I am not going deep with them at the moment just trying to find the sweet spots with them across the FL range... I also have a Tamron 10-24 DiII to try out not expecting much from that unless its stopped down to at least f5.6 and maybe even f8.0

[Yoddha]

Beautful image Peter! I like the star colors contrast