M45 with astrotrac

[stan26]

1hr and 15minutes data total, but this time and for the first time ever I imaged using my 200L lens "wide open" at f2.8. In the past I have always stopped it down to around f4.....I'm now realising that stopping it down in the past could have been costly in terms of photons.....

Modded Canon 1100D, ISO800, 5minute subs,  Canon 200L f2.8 (@f2.8), Hutech IDAS P2 MFA filter, Astrotrac TT320 bolted onto DIY wedge.

Stan

Hope the pic loads...? (new flickr is confusing)

[robbie c]

That looks lovely Stan you got some nice colour in that image well done 

[RT65CB-SWL]

Wow! That is the best picture of M45 I have seen anywhere.

[tdmodels]

Lovely image Stan and 5 min subs using the 200mm on an Astrotrac is very good.  I notice the brighter stars have halos around them. Was this down to dew?

[stan26]

Thanks Guys.

Tim - There was no dew present throughout the session, I think the halo's are a result of the IDAS filter. Its the rear mounted MFA version and I think I maybe getting some internal reflection off the brighter stars. When I minimised the stars I could have greatly reduced the halo's but I didn't think they were to distracting so I left them in the image. 

Cheers

Stan.

[Quatermass]

Cracking image Stan that astrotrac is awesome

Sent from my Nexus 7 using Tapatalk

[stan26]

Cheers QM, Yes the astrotrac is a wonderfully simplistic bit of kit, I just need to tweak my wedge alignment for these long exsposures, theres still a bit of trailing in there. Periodic error is almost non existent at telephoto FL's upto 400mm. With the wedge bolted onto my old EQ pier I reckon I can be setup an imaging in around 2minutes!  

Cheers

Stan

[fwm891]

Wow - that is superb

[Zakalwe]

Lovely image and really well processed.

[symesie04]

Very nicely done James. Loads of detail. Ive been having a few issues with my Astrotrac it has to be said, but hopefully they are sorted now and i can put your ex 500d to work

[Psychobilly]

Superb result.. I'm hoping to have a few clear nights over my extended Christmas Break and woul be chuffed to get anywhere close to your result

Badly typed on my Galaxay S4 in Tapatalk4

[StuartJPP]

Nice one Stan, some great detail there and nicely processed.

I always shoot wide open, unless it is a particularly bad lens and the Canon 200mm f/2.8 can handle it. As you say, no point spending all that money on a wide sharp lens to just stop it down.

Recently I took a few subs of M45 with and without an Astronomik CLS-CCD clip filter, both had halos around bright stars. I also took a few frames using my unmodified Canon 7D and there were no halos. I suspect it is either UV or IR bloat and am now suspecting that the "front" filter on its own isn't quite cutting it (pun intended).