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M81 & M82 Against all ods

glennbech

By glennbech
in Imaging - Deep Sky

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glennbech

glennbech

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Last night was one of those nights where nothing ground breaking would emerge; the moon washed the sky out in a blue haze and there were slow moving patches of clouds drifting slowly over all constellations making long exposure work impossible.

I was in the mindset that I had nothing to lose; the megrez 90 would not miss out on any Sharpless objects that night. I decided to instead bring out the "Big Gun" (8" Newtonian) and do my first attempt at guiding and multiple exposures with that since I modified my 10D.

The 10d is rather heavy and weighs at least twice as much as the 400D/350D. Balance is impossible with a side by side bar, guidescope, guide scope and finder. I was real curious of how guiding would turn out. Star Alignment was the hardest part; involving standing on a chair and a table. I did not want to turn the scope in the tube rings after I had tried to balance it.

I guess the conclusion is that I'll take out the Newt more often for an imaging session. It's a big beast to setup, but even unbalanced the HEQ5 Pro seems up to the task (when there is no wind at least..) :)

Here is the "cactch" from last night. This is only 12x40 seconds. After working with 90mm @ f/5.5 I was real surprised to see how fast the galaxies revealed themselves. I also did about 20 x 2 minute subs that didn't turn out too well due to clouds, but At least I got to try out guiding. To my big sureprise I was able to successfully guide to at least 4 minutes with the Helios startravel 80 with no barlow.

9526_normal.jpeg

(click to enlarge)

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glennbech

glennbech

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I use an 8" Newt and keep having a bash at those two but they never come out as nicely as that.

I think the modified DSLR can be attributed to a lot the detail in M82. I've seen shots with unmodified cameras and the cool red glow from the core is a lot less distinct.

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Psychobilly

Psychobilly

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Cracker Glenn :)

Thats a pair that I visit quite often as well ... I have a new "project" waiting for clear skies... only managed one sub the other night and really need a load more and hopefully got a new toy on the way next week so its bound to be cloudy for a few weeks :D

Billy...

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glennbech

glennbech

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I have a new "project" waiting for clear skies... only managed one sub the other night and really need a load more

Sounds interesting! I really want to have a go at M82 / M51 with my 1800mm f/12 Mak. Im real curious to see how the guiding will be. I recon that If I can drift align fairly good first I'll have a chance :) I'm thinking maybe 100 or so 2 minute ISO 1600 shots.

My experience so far with NGC 1333, M82 and various other "bright" objects (compared to my sharpless nemesis!) is that you don't get too much more data out of it after the first minute or so. There is really no use to go "deep" on a bright object with a pretty defined shape. (Like M51, M82) To catch faint details, filaments and nebulousity the exposure time of course makes a huge difference. Do others agree?

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Psychobilly

Psychobilly

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Hi Glenn,

Im thinking of M82 at F20 on the 8" 4046mm .... had a quick go the other night ... had an ETX105 OTA as a guide scope no probs with M82 as theres a nice bright star just along side... framings a challenge though and the poor old CPC mount needs some TLC :)

Billy...

p.s. the new toy is hopefully a Megrez 72 to repalce the Equinox-66 which has been reduced to spotting scope duties.. the focuser only works with the tension backed right off so is no good for imagign anymore...

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Tim

Tim

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You are right there Glenn. Watch the histogram. Ideally the result should be away from the very left side, but if it is edging past halfway (on its left extremity) then its probably going too far.

Its amazing what you can do with RAW files, but the biggest improvement in my images came when I stopped exposing past that point. Jerry Lodgriuss (sp?) had an article about it for dslr's in last months Sky & Telescope.

It'd be well worth doing an objective comparison on successive shots to find your optimum bracket. From home I like the right hand edge of the histogram to be no more than half way, due to the LP here. But from a dark sky you can go further left and bring out the finer (darker) bits more succesfully.

M81 is my nemesis. I cant seem to get a decent picture of it. The goto struggles to find it, its hard to centre, and it just wont seem to image brightly from where I am. Gonna have another go at it later in the winter. Your camera has picked it up nicely though.

TJ

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Whippy

Whippy

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Good effort Glenn. It looks like i'll be joining the growing band of fast newtonian imagers too soon and with results like these, it's not hard to see why it's becoming more popular...

Not the best time at all to get these two, in fact probably the worst! Give it a couple of months and these two will be nice and high, out of the murk. Give them a go then and smile :).

Tony..

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glennbech

glennbech

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Im thinking of M82 at F20 on the 8" 4046mm .... had a quick go the other night ... had an ETX105 OTA as a guide scope no probs with M82 as theres a nice bright star just along side... framings a challenge though and the poor old CPC mount needs some TLC

I've been wanting to ask you what the skywatcher equivalent the CPC mount is. EQ6, HEQ5 ?

*grin* 4046mm... I reckon you're gonna barlow your way up there? With my new guide rings, I have no problems whatsoever with guide stars. Me so happy!: :) The largest frustration killer apart from my mains connection to the HEQ5 Pro mount

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glennbech

glennbech

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Not the best time at all to get these two, in fact probably the worst! Give it a couple of months and these two will be nice and high, out of the murk. Give them a go then and smile

They're actually that bad..... at 5 in the morning that is (52 degrees up) :)

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Whippy

Whippy

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Not the best time at all to get these two, in fact probably the worst! Give it a couple of months and these two will be nice and high, out of the murk. Give them a go then and smile

They're actually that bad..... at 5 in the morning that is (52 degrees up) :D

:) And astronomical darkness ends at about 5.40....

Tony..

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Psychobilly

Psychobilly

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Im thinking of M82 at F20 on the 8" 4046mm .... had a quick go the other night ... had an ETX105 OTA as a guide scope no probs with M82 as theres a nice bright star just along side... framings a challenge though and the poor old CPC mount needs some TLC

I've been wanting to ask you what the skywatcher equivalent the CPC mount is. EQ6, HEQ5 ?

*grin* 4046mm... I reckon you're gonna barlow your way up there? With my new guide rings, I have no problems whatsoever with guide stars. Me so happy!: :) The largest frustration killer apart from my mains connection to the HEQ5 Pro mount

The CPC800 is Alt/Az on my home made pier/wedge in the obs I built this spring...

Think the RA bearings need a bit of work...

I was using a x2 T-mount teleconvertor that i just happened to have lying around... hoping to reduce vignetting over a barlow... I can go F30 for 6096mm using a powermate but thats just geting silly...

which is probably a bit apt for me...

As I am a Silly Billy at times... :D

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glennbech

glennbech

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And astronomical darkness ends at about 5.40....

That is about when I start shooting darks & flats ! :)

I also have 40 more minutes than most of you guys&gals from the UK. The sun rises 15 degrees below horizon at around 06:15 for me at the moment :D

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Whippy

Whippy

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And astronomical darkness ends at about 5.40....

That is about when I start shooting darks & flats ! :)

I also have 40 more minutes than most of you guys&gals from the UK. The sun rises 15 degrees below horizon at around 06:15 for me at the moment :D

Really? I'm intrigued as to where you are..

Tony..

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