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5 hour exposure of M81 and M82

Altais

By Altais
in Imaging - Deep Sky

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Altais

Altais

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Good evening everyone. Here's an image of M81 and M82 that I captured last weekend and finished processing today.

post-43721-0-61048300-1443556390_thumb.p

52 exposures of 6 minutes for a total of 5.2 hours of integration time, at ISO 1600, calibrated with flat and bias frames. I used my full spectrum modified Canon EOS 1100D with a Skywatcher Explorer 150PDS on an EQ5. Processed with PixInsight and Photoshop. The guiding worked really well, despite quite a bit of wind, and usually stayed within a couple of arcseconds.

The above image is stretched to show the faint IFN, but it could do with some more integration time, so at the moment I think it looks better with a cleaner background as in the below image.

post-43721-0-44089600-1443557225_thumb.p

Hopefully I'll be able to get some more exposures soon to bring out the IFN.

Any tips for improvement is much appreciated.

Clear skies,

Lars

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Altais

Altais

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Thanks a lot guys!  :grin:

Lovely shot ...  :smiley:

But what's the spikey thing coming in from the bottom left ... ?

It's probably a reflection from something in the optical train. Might be the coma corrector, as I've taken a lot of images without it and not gotten any reflections.

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Altais

Altais

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Thanks everyone for the encouraging feedback!

I think that is a lovely image. I like the subtle colours. Which EQ5 mount do you have? I can't guide my old EQ5.

I have a basic EQ5 with a dual axis motor set attached, as well as a handset like this, which has an ST-4 port for autoguiding. Why can't you guide with your EQ5?

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Ouroboros

Ouroboros

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Thanks everyone for the encouraging feedback! I have a basic EQ5 with a dual axis motor set attached, as well as a handset like this, which has an ST-4 port for autoguiding. Why can't you guide with your EQ5?

I only have one of the original handsets which has no ST4 port. I like the look of those new handsets, but I might just be throwing money away given the poor mechanical quality of my old mount.

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Altais

Altais

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I only have one of the original handsets which has no ST4 port. I like the look of those new handsets, but I might just be throwing money away given the poor mechanical quality of my old mount.

I found it a bit fiddly to get it guiding properly, as the (in)balance has to be just right to avoid oscillations, and the backlash is quite significant. But it guides pretty well now that I've found a configuration that works. A 200mm like yours would probably be too much of a load though, at least if there is any wind.

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Xplode

Xplode

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Thanks a lot guys!  :grin:

It's probably a reflection from something in the optical train. Might be the coma corrector, as I've taken a lot of images without it and not gotten any reflections.

I think it might be the coma corrector too since i also had some reflections with the Baader MPCC III

Very good image, i like your improvement since last season  :smiley:

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Ouroboros

Ouroboros

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I found it a bit fiddly to get it guiding properly, as the (in)balance has to be just right to avoid oscillations, and the backlash is quite significant. But it guides pretty well now that I've found a configuration that works. A 200mm like yours would probably be too much of a load though, at least if there is any wind.

Yes, probably. The longer focal length would make more demand of the mechanics of the mount too. Nevertheless your marvellous image demonstrates well what can be achieved with this system.

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