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Eeyarn

First attempts at galaxy images

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so had a couple of clear-ish nights recently and wanted to try imaging some galaxies, these are my first attempts and i know they're not amazing but im really pleased with how they have turned out. alot of light pollution near me and im struggling with alignment so exposures are quite short but let me know what you think. 

post-31733-0-61531000-1393437425_thumb.j

Triangulum galaxy 35x45s lights, darks and bias

post-31733-0-97594200-1393437646_thumb.j

m109 20x45s lights, darks and bias

post-31733-0-09666600-1393437744_thumb.j

M101 40x50s lights, darks and bias

iain

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To me they look fantastic after seeing my photos of the andromeda galaxy that i tried a few weeks ago....  its a steep and expensive learning curve and im still at the bottom of both. 

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Excellent work Iain. If you add some flats then you'll be able to correct the vignetting. It's easy to do. I use a white T-shirt stretched over the opening of the OTA.

Dave

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Hi Iain,

Yep, definitely need some flats - will make a big difference and also allow better processing. If your using a dslr, I don't think you need bias frames.

Louise

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you have every right to be pleased with these

some flats would be useful, they aren't difficult and once you get used to the routine you wont want to image without them  

Thanks for sharing

Bryan

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thanks for all the comments, yeah will definitely be trying flats next time i was unsure about whether i needed bias frames but had just seen it in an online tutorial an they don't take long so just added them in. thanks for the advice everyone. 

iain 

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Just a quick one what are your skies like as I can never bring out the arms even on M31/M81?

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they're a good start... what were they taken with?

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they're taken using a SW 150pds on an EQ5 no goto just motors, and an 1100d then dss and photoshop.

skies are really light polluted hence the short exposures (and i cant align very well yet) 

post-31733-0-21216800-1393706430_thumb.j

thats a single 50 sec frame of M101

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i'm not the most knowledgeable imager here but i would recommend getting a coma corrector. i use a baader corrector and it makes a significant difference

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yeah thought about coma corrector but saving for a new mount at the moment i want goto as i can spend hours just trying to find objects, if its faint its drowned out by LP. there's so much i want to buy but havn't got the cash haha 

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they're taken using a SW 150pds on an EQ5 no goto just motors, and an 1100d then dss and photoshop.

skies are really light polluted hence the short exposures (and i cant align very well yet) 

attachicon.gifIMG_1491_____2.jpg

thats a single 50 sec frame of M101

Hi again It's worth getting a lp filter such as an Astronomik cls-ccd. I have the same lp problem here in Glasgow city. The cls-ccd helps a lot (but doesn't cure). I've yet to try to image a galaxy but that's largely due to the combination of rubbish weather and a severely limited view of the sky. I'm sure Glasgow is the cloudiest place in the uk!

Louise

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yeah lp filters on my list too but iv heard it produces a very greenish blue tint to the image if its not a modified dslr tho ? i may have misunderstood or be thinking of something else i read that much stuff an then forget half of it haha but do want one at some point 

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yeah lp filters on my list too but iv heard it produces a very greenish blue tint to the image if its not a modified dslr tho ? i may have misunderstood or be thinking of something else i read that much stuff an then forget half of it haha but do want one at some point 

They shift the white balance but that is easy to process out. In fact, stacking with flats seems to largely correct it. Of course you have to take the flats with the clip filter in situ. They are quite expensive but I feel better to get one before a coma corrector. You can process out coma distortions in e.g. StarTools, I believe. I'm still learning the processing side - I need more images!

Here is full size image I made of NGC 6940 - you can see the increasing coma towards the corners. I can live with it for now and I haven't tried correcting it.

post-33532-0-41666800-1393712901_thumb.j

Louise

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As mentioned previously, get some flats done. It will allow you to extract the maximum amount of potential from your data - and with a newt its pretty much mandatory. When you have finished your session and done your flats - leave the camera in place (dont touch it!). That way you can reuse your flats over and over again.

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That's a very nice image there Louise. I have the SW coma corrector and it works a treat. It also has the benefit of keeping the camera sealed up so you don't get dust on the sensor.

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Hi Iain and a nice set of images from another fan of DSO objects.

If you have PS you can get Astronomy Tools Actions and it will get rid of the vignetting amongst other actions in the package.

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That's a very nice image there Louise. I have the SW coma corrector and it works a treat. It also has the benefit of keeping the camera sealed up so you don't get dust on the sensor.

Thanks! It's not that good really but certainly shows off the coma! I think I've tweaked the contrast too much on that one and killed most of the colour. Yeah, I probably should get a corrector at some point though I'm thinking about getting a modded DSLR at the moment. How does the SW corrector affect the backfocus? I'm also thinking about getting some narrowband filters but I'm not sure about using a dslr with a filter wheel as well as a coma corrector...

Louise

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latest image m51 60x60s lights and darks tried flats but they caused a really bad gradient from top to bottom, so didnt use them in the end just used Photoshop to get rid of the vignette, really pleased with this one 

let me know what you think. 

iain

post-31733-0-33214500-1394150047_thumb.j

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I use a Canon 1100d also and had trouble with flats until recently.  The answer for me was to sit the telescope a foot or so away from a white tv screen with a white shirt stretched tightly over the end and simply use the AV function.  There are many ways to take flats but this is what worked for me.  Many people use daylight but if the white screen works for you it will save having to do them the day after.

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I use a Canon 1100d also and had trouble with flats until recently.  The answer for me was to sit the telescope a foot or so away from a white tv screen with a white shirt stretched tightly over the end and simply use the AV function.  There are many ways to take flats but this is what worked for me.  Many people use daylight but if the white screen works for you it will save having to do them the day after.

Opening Notepad on a monitor has worked for me :). Had the end of the scope not far from the screen and took exposures in AV. Having said that, I've never actually analysed my flats. There is software - CCDInspector - available for doing that but it costs $180.... It might be worth getting though - probably worth the expense compared to time spent trying to figure out image quality problems which might simply be caused by poor flats.

Louise

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