M45 Pleiades 9-10 October 2015

[The Thing]

This is my first attempt at a mosaic. I have been trying to get rid of the obvious join with various pieces of software but have given up, partly because of the huge spikes on the top frame. That's what comes of having bright stars just out of shot. Next time I will use EQMosaic to position the frames and minimise overlap

This is 5h 20m or 65 x 300s @ISO800 taken over two nights, the first of which was a bit murky (lower frame). DeepSkyStacker did an excellent job of matching the images which were slightly relatively rotated. The calibration files were in the Master Group and the two sets of lights in two other groups.

Image date, time and location:   20151010 Manche, France
Telescope aperture and focal ratio:   Meade LX90 8", Baader Alan Gee II Telecompressor
Camera and filters used:   Canon 1000D Modded, no filters
Processing applied:   Deep Sky Stacker, uncropped.


Click for a much larger version, which is still only 60% of full size.

[Fay]

try Microsoft Ice, free

[Carole]

Looks like good data and quite noise free for a Canon too, hopefully there will be something out there that will work, I have never done a mosaic except to stitch it together manually.  You'll have to get yourself a smaller scope for larger objects Duncan. 

Carole

[The Thing]

try Microsoft Ice, free

It might be free but it had no idea!

[RobertM]

Nice try Duncan, good colour coming out on the left but those spikes definitely make processing a challenge !!!

Robert

[The Thing]

I was just happy to see the detail I've captured in the dust. I don't think I've ever captured data of this quality before, which is great since I am essentially using the same gear. Just shows you need to keep refining technique and don't blame the tools. If only I could crack processing!

[Carole]

Just shows you need to keep refining technique and don't blame the tools.

Also you now have darker skies.

Carole

[The Thing]

Ah but I never managed it at a DSC.

[Carole]

I can't get over the fact that there is no noise and it's a DSLR.

Carole

[JohnP]

Looks like a pig to process Dunc.. you'll never get it perfect with those spikes... You have some nice brown stuff going on though down the LHS... Shows real potential.  John

[The Thing]

I can't get over the fact that there is no noise and it's a DSLR.

Carole

I'd better write down my DeepSkyStacker settings immediately! It's well dithered, 5 pixels in RA and Dec (top setting in APT) with PHD's Dither ratio set to one.
One thing I did do differently was take my flats with an EL panel, not sky flats with a diffuser - but this shouldn't affect noise. The CCD temperature was 16C and ambient about 10C.

[MarkS]

That shows huge potential Duncan.  It's great to see the Pleiades at such a large scale - what a shame it doesn't fit the sensor without a mosaic.  You have good star colour.

I would take a closer look at the subs - to me it looks like there is a qualitative difference between the 2 parts of the mosaic possibly caused by an invisible layer of high hazy cloud:  the bottom star has the "headlamp in fog" effect and looks very different to the upper star which has a clear halo.

Mark

[The Thing]

I would take a closer look at the subs - to me it looks like there is a qualitative difference between the 2 parts of the mosaic possibly caused by an invisible layer of high hazy cloud:  the bottom star has the "headlamp in fog" effect and looks very different to the upper star which has a clear halo.

Mark

It was over two nights and the first was hazy and the seeing was worse. Also the first night was partly pre streetlights off time so the murk was illuminated.

I have a cunning plan which will depend on if EQMosaic can be triggered to move by a script. I see if I can set an APT exposure plan to do ~5x300s subs, run a script to kick EQMosaic to the next location and then ask PHD to choose a guide star and start guiding again, wait a minute or two for guiding to settle and then repeat. APT plans can be set to repeat a # number of times. That way as conditions change on average the subs for each area will be the same when stacked.

[JohnP]

Blimey Duncan sounds complicated. I reckon it'll be easier to get a camera with bigger sensor or a scope with shorter fl.... 😁

[The Thing]

But that's no fun. I really enjoy messing around to see what I can achieve with what I've got. I do plan to get a new scope and keep window shopping but we have a house build to pay for at the moment :{

[JohnP]

I know... In similar boat (not the bit about the house to build but putting two kids through uni simultaneously must be close... ) - Anyway I'm looking to resurrect my old Intes Micro MN56 - 5-inch F6 - with really good Russian optics... Only problem is to use it with my current setup I'll need to move primary up the tube... so hey ho here goes with the Black & Decker... It also has a really small secondary like 20% so am thinking vignetting may be an issue with the CCD in my Atik 314L - dunno though need to do some testing - like you say its fun seeing what you can get with the equipment you have...

Anyway, look forward to seeing the results of your tests...


John