M16 Eagle Nebula

[Garbz (Chris)]

Finally had the chance to leave the suburbs of Brisbane. Travelled to Kilcoy to get away from the light pollution. All I can say is WOW. We don't see the milky way at home.

I'm blown away at how much you can do with less out in the dark. I took this shot of the Eagle Nebula and only recorded 1h20min worth of usable data in 2min subs. The picture absolutely blows away my previous attempt from the city despite having more than double the exposure.

[David Fitz-Henr]

NIce work Chris, some good colour and detail there! What equipment are you using? The only thing I would mention is there appears to be some field curvature (?) in the outer regions of the image.
It would also be interesting to compare against your previous attempt from the city.

[Garbz (Chris)]

Probably not a fair comparison but in this thread I complained about the result: http://www.iceinspace.com.au/forum/s...ad.php?t=94148

Even despite all the noise, much of which is to do with the camera I was using and the other half being the extreme curve applied you can see significantly more stars and nebula in the recent shot.

I'm shooting with a D800 and Celestron C8 mounted on a NEQ6, guided with a 50mm Orion finder guider. I'm using the cropped frame 24x16mm but it's still a relatively large sensor. I get those edge distortions despite using a field flattener. It's worse without it.

[alpal]

That looks like field rotation from the guide star being too far
from the main frame & the drift alignmment out - strange?

You certainly grabbed some detail in the core.

[Ross G]

Nice photo Chris.

Great detail.

Ross.

[David Fitz-Henr]

Originally Posted by Garbz

I'm shooting with a D800 and Celestron C8 mounted on a NEQ6, guided with a 50mm Orion finder guider. I'm using the cropped frame 24x16mm but it's still a relatively large sensor. I get those edge distortions despite using a field flattener. It's worse without it.

I have found that field flatteners are quite sensitive to the separation between the imaging chip and camera. It does not appear to be field rotation as the off-centre stars are most definitely out of focus compared to the central region. If possible do some tests with varying distances between the flattener and the camera. Here is a link to my pbase site showing some tests that I did with a Newtonian / Paracorr showing significant improvement when the optimal separation is determined: http://www.pbase.com/david_fitz_henry/image/124811410

[Garbz (Chris)]

Originally Posted by alpal

That looks like field rotation from the guide star being too far
from the main frame & the drift alignmment out - strange?

Doubt it's field rotation as I see the same effect in my 10 second test shot I did while making sure the scope was pointed in the right patch of sky.

Originally Posted by Ross G

Nice photo Chris.

Great detail.

Ross.

Thanks Ross.

Originally Posted by David Fitz-Henr

I have found that field flatteners are quite sensitive to the separation between the imaging chip and camera. It does not appear to be field rotation as the off-centre stars are most definitely out of focus compared to the central region. If possible do some tests with varying distances between the flattener and the camera. Here is a link to my pbase site showing some tests that I did with a Newtonian / Paracorr showing significant improvement when the optimal separation is determined: http://www.pbase.com/david_fitz_henry/image/124811410

Interesting. I'll see if I can rig up something to let me adjust the spacing from the camera to the scope. At the moment I have only a fixed adapter for the Celestron C8 which is designed for use without a field flattener. Mind you even without it I still get a similar image. Think it's time for a trip to the hardware store.

[peter_4059 (Peter)]

You are making amazing progress Chris considering you only purchased your mount and scope a few months ago. It took me years to produce a half decent image. Just need to work out that flattener now.

[Garbz (Chris)]

Couldn't have done it without your advice Peter