Sigma 85mm Art First Light

[Atmos (Colin)]

About two months ago or so I bought a Sigma Art 85mm F/1.4, it had some QE issues in regards to the auto focuser. Had it out under the stars to see what it was like optically and it had some zonal errors at F/2.8 and F/4, star shapes moving in different directions across the frame. Decided to get a replacement due to the auto focuser motor, seemed that if the focus motor made it though QC the optics seemed to have as well.

Well yesterday afternoon I picked up its replacement, took a couple of months but OMG it is sharp. Sadly I last 1/2 of my data last night due to the Q setting on my Nikon D7200. I know I cannot use the Mirror Up setting with an intervalometer but I was hoping that the Q setting (designed to be quiet, slows down the timing between mirror up and exposure) would relax any potential mirror shutter, and it did, but also only saved every second exposure for some reason.

This is 44x120s of Rho Opt with a Nikon D7200, Sigma 85mm F/1.4 @ F/2.8. Haven't done any calibration as of yet, just wanted to see what would show but I'm planning on getting another 6 hours or so tonight so I'll get all of the stuff then.

Processing has been a run of ABE, colour calibration, histogram stretch and 30s of playing with curves.
All in all, very happy with the lens! By tomorrow I hope to have flats, darks, bias and ~8 hours of exposure.

[Retrograde (Pete)]

Looks great!

Whole Rho region including Blue-horsehead in the one frame

[traveller (Bo)]

That looks great Colin.
Go out this weekend and do more
Bo

[strongmanmike (Michael)]

That's pretty nice Col, I agree with Bo, more please

Mike

[atalas]

Looks great....got a bigger image Col?

[Atmos (Colin)]

Originally Posted by Retrograde

Looks great!

Whole Rho region including Blue-horsehead in the one frame

Sigma Art 50mm would fit it all in better

Originally Posted by traveller

That looks great Colin.
Go out this weekend and do more
Bo

Originally Posted by strongmanmike

That's pretty nice Col, I agree with Bo, more please

Mike

Car is packed and I'm gonna leave soon!

Originally Posted by atalas

Looks great....got a bigger image Col?

I'll hopefully get one up tomorrow after I've got some more data and done some calibration. It'll give me something to do at 6am when I'm freezing in my caravan
Current weather forecast for Heathcote is -3° but a feels like of -7°C

[multiweb (Marc)]

Wow! That's very cool.

[Paul Haese]

Like this Colin. Nice colour and processing.

[gregbradley]

That's a great image Colin. I am doing the same thing right this minute with an 85mm lens. Great minds eh?

Greg.

[Ryderscope (Rodney)]

Seriously nice, great colour and well resolved.

[Camelopardalis (Dunk)]

Now you've got me drooling...what a cracker

Did you take any shots wide open to see what the corners were like then?

[RickS (Rick)]

Looks like a keeper this time

[Stevec35 (Steve)]

Wow - really like this Colin! Looking forward to many more.

Cheers

Steve

[alan meehan (Alan)]

Colin that's a real nice rho there colour and processing is beautiful
AL

[Decimus (Richard)]

What a fantastic image, Colin. Did you use the DDM60 mount? The lens is a corker - little wonder that it received the highest score for a lens on DxOMARK. It was a more than even match for the Zeiss Otus! Great work.

Cheers,
Richard

[glend (Glen)]

Wonderful Colin. Where did you buy from?

[Atmos (Colin)]

Originally Posted by multiweb

Wow! That's very cool.

Originally Posted by Paul Haese

Like this Colin. Nice colour and processing.

Thanks

Originally Posted by gregbradley

That's a great image Colin. I am doing the same thing right this minute with an 85mm lens. Great minds eh?

Greg.

What lens are you using? I wasn't entirely impressed with the Nikon 85mm F/1.8G.
85-135mm is pretty much perfect for this area.

Originally Posted by Ryderscope

Seriously nice, great colour and well resolved.

Thanks Rodney, cannot wait for next new moon to find some more targets to hit!

Originally Posted by Camelopardalis

Now you've got me drooling...what a cracker

Did you take any shots wide open to see what the corners were like then?

I'll have to give that a shot but no, I haven't. I have shot at F/1.4 in the house though and it is noticeably soft, longitudinal chromatic error but I'll give it a shot.

Originally Posted by RickS

Looks like a keeper this time

I'm pretty happy with its performance. I should test its performance from F/2 to F/4 to see what I can do with it.

Originally Posted by Stevec35

Wow - really like this Colin! Looking forward to many more.

Cheers

Steve

Loving the lens! I should get some adapters to connect it to my QHY163 for some wide field HaOIIISIILRGB imaging

Originally Posted by alan meehan

Colin that's a real nice rho there colour and processing is beautiful
AL

Thanks Alan. I've done a drizzle integration version which I'll do some processing on when I get some time

Originally Posted by Decimus

What a fantastic image, Colin. Did you use the DDM60 mount? The lens is a corker - little wonder that it received the highest score for a lens on DxOMARK. It was a more than even match for the Zeiss Otus! Great work.

Cheers,
Richard

Thanks Richard. Actually shot it with my HEQ5 on the first night and my EQ6 on the second. Not sure whether the slight shift in the first image was caused by my PA being slight off or if it was periodic error.
Yesterday afternoon I managed to get four ADM plates bolted together allowing me to get enough weight on the camera side to be able to balance on the DDM60. My current counter weight shaft is 400mm and is too heavy for light loads, thinking of getting a 150mm one machined at some point but next new moon I'll use my Losmandy plate stack and use it

Originally Posted by glend

Wonderful Colin. Where did you buy from?

Got it from my local Teds store. One of the guys at mine is a pleasure to deal with, one of the others, not so much