M8M20M21 new rig test

[ReaPerMan]

I have recently set myself up with a new portable rig comprising a Telescope Express Imaging Star 71mm F 4.9 5 element APO, Skywatcher AZEQ5GT & Skywatcher Synscan Guider. Prior to heading out to the bush I thought that it would be nice to test it out to get a feel for how wide a pic it took and so I mated to my Sony A7s and tried it out with some Easy M8 and pals! After a really simple to do 2 star align and polar alignment the target came in exactly as shown in the pic. The picture itself is 42 X 15 seconds (lots of LP so time was kept low) at ISO 3200. I think the result is not bad and I'm looking to get it out of the LP and into the dark skies ASAP. The pic was processed in Pixinsight (DBE applied to get rid of the LP) and finished in photoshop. Overall I'm happy with the gear and I'm thinking of all the targets that will do it justice.


Large Pic http://www.astrobin.com/full/217163/0/

There is also a version with 5 minutes of integration and using the Unmodded Canon 6D http://www.astrobin.com/full/215998/0/

Thanks for looking

Paul :thumbsup::thumbsup:

[Paul Haese]

Paul this is a great field of view and shows so many interesting areas around the trio. The colour looks good too.

[ReaPerMan]

Thank you Paul.
I'm looking forward to being able to image a little deeper with this setup 10 minutes in total hardly counts as real integration time.

all the best

Paul :thumbsup:

[AlexN]

Considering this is 10 minutes of total exposure that is without a doubt a ripper of an image. As someone who has spent literally hundreds of hours imaging this area of the sky I can say I've never achieved something that nice in 10 minutes.

[ReaPerMan]

Thanks Alex

The combination of F4.9 and the A7S gets a quick result. I have seen some maths that suggest there is not much more to be gained from an A7s attached to a fast scope beyond 30 secs at ISO 3200. I have seen really deep pics with stacks of 150 to 200 at this setting as soon as I get some dark skies i will be trying that out

Paul :thumbsup:

[AlexN]

I'd love to put an a7s on the back of my 300mm f/2.8.. Even with just my 450D it manages to get down to magnitude 13 in 1 minute. In dark skies with the a7s I'd imagine it would dig deep.

[ReaPerMan]

I have used it on my 300mm F 3.8 in suburban skies it starts to 'white out' at 20 seconds. Lots of DBE needed to fix the pics.

[alpal]

Nice work Paul,
I like that little scope:
http://www.teleskop-express.de/shop/product_info.php/language/en/info/p7085_TS-Imaging-Star71---71mm-f-4-9-Imaging-APO---covers-full-sized-sensors.html

I wonder if it has enough back focus to use with a QHY9m camera?

cheers
Allan

[RickS]

Nice golden stars! Looks great, Paul.

[ReaPerMan]

The current setup with the A7S is
Scope, M48-Canon adaptor, Mallabones Canon - Sony E adaptor, Sony A7S after focusing of 18mm of draw tube travel this makes approximately 70mm to the sensor face. There is plenty of draw tube travel left so I think that you should have no problem in getting a QHY9 to focus. At some point in the future I would like to try it with my 11002M and Filter wheel.



Thanks rick it's all down to Pixinsight's great DBE feature. There was some smoke haze in the air on the night I took the pic so there was a 'generous ' amount of LP to be dealt with. attached is an example of 1 sub showing the LP prior to removal.
:thumbsup:

[AlexN]

That's crazy how good the resulting image is despite the LP present in that frame. A testament to good processing.

[gregbradley]

That's a great image. At some point I plan to attach my Sony A7r to my AP RHA to see what it can do. A bit of mirrorless camera goodness would be nice.

Despite both these cameras (and most modern DSLRs as well) being excellent at high ISO the fact that dynamic range drops heavily once you get above about ISO1600 means that you are better off with longer integration time than simply using high ISO.

High ISO low noise is really best for nightscape up to 30 seconds perhaps even 90 second type shots.

Do you use a light pollution filter? I take it your A7s is unmodded?

Greg.

[ReaPerMan]

Thanks Alex I keep trumpeting about PI's DBE module It really is the bomb for getting the LP sorted.



Thanks Greg,
I don't have a LP filter at this stage and the LP was exaggerated by smoke haze. Tonight looks clear so I'm hoping for some better results. Yes I know what you mean about the High ISO and I saw some reference by Fritz Helmut Hemmerich and his awesome A7S pics. He states that the dropoff for the A7S is ISO 3200 and suggests that that is the sweetspot with 30 second exposures. I encourage you to get some mirrorless love! :) we would all like to see the resulting pics

all the best

Paul :thumbsup:

[AlexN]

I've got to give PI a fly I think.