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pic info: m31, 82frames, 13 min 40 sec total, iso3200.

Taken with canon 550D at EF50 1.4 @ 2.8, 10 sec frames.

Sooo, as it was waaay too cloudy to long exposure at the time i took these, i decided on taking many high iso short exposures untill the clouds went away (they never completly did, lol).

took a total of around 160 frames, out of where 82 got stacked, and here's the result. well, two actually, not sure wich one i like the best.

Also attached a timelapse of some of the frames, just to show the conditions... :icon_confused:

post-22179-133877698904_thumb.jpg

post-22179-133877698912_thumb.jpg

m31-timelapse.zip

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Amazing images! what program did you use to stack them? did u use a tracking mount? this is the kind of image i have been trying to capture. so neat

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Thanks for the response! :icon_confused:

I'm quite surpriced i got anything ~ok out of it too, concidering the weather and only 10 sec exposures. But for a low res pic, it's actually clear and noise-free enough :rolleyes:

I stacked the pictures in deepskystacker, then processed rather quickly in photoshop. The camera was put on a HEQ5 tracking mount, yes. Shoots was taken remotely so it didn't shake the camera/mount.

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That's come out very nicely. The f/1.4 does seem to do a much nicer job than the f/1.8 based on that (not tried mine as yet). The stars at the edges look pretty good (at this scale). Mounting that on an HEQ5, you should be able to hit 5 minute exposures easily.

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yep, the 1.4 is much better then the 1.8. But still, at 1.4 it looked really really horrible, and at 1.8 as well, so had to step it down to 2.8 to get somewhat round stars. a shame, i would get a Lot more data at 1.4, but oh well...

mike; will definally try longer exposure at a later time, but will give it a try at ~250mm instead then, to get closer and yet be able to see the whole galaxy (i can't in my telescope, it's just too big this thing, haha) ;)

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The 1.8 has to go to at least f/4 to get somewhat decent stars, so at f/2.8 that's a full stop faster ;)

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Thats fab... you've done a great job on the gradients.. they must have been a pain.

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The 1.8 has to go to at least f/4 to get somewhat decent stars, so at f/2.8 that's a full stop faster ;)

I 'invested' in a superfast Nikon F1.2 which turned out to be usesless for astro wide open- needs stopping down to f2.0 at least. Could have saved a packet and bought the F1.4 or even F1.8 instead. Had I got a few £K spare the legendary Noct Nikkor F1.2 is good for astro wide open apparently......

Nikon 58mm f/1.2 Noct-NIKKOR

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Nice image! I think if you move the frame a little you could have included M33 triangulum galaxy too. (it's just a little further past Mirach)

You picked up a couple of clusters near the right of the frame too. Pretty cool shot!

Doug

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Nice image, might have a go with an old pentax lens at f1.2 fully manual. Such a nice lens. Well done on the picture.

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Did you use darks and flats with the stack? It looks really nice a lot better than I have done as of yet...flat wise, you even need them with a normal camera lense? The ones I tried taking I don't think my light source was right for it, but they didn't really make a difference when I staked all my images...granted though I have long exp and high iso noise reduction on like a noob.

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Thanks for all the feedback n_n

Nice image! I think if you move the frame a little you could have included M33 triangulum galaxy too. (it's just a little further past Mirach)

You picked up a couple of clusters near the right of the frame too. Pretty cool shot!

Doug

Absolutelt possible it seems, i was thinking the same after i had processed it and looked at the FOV i used in stellarium. Though, M33 is a lot fainter, so not sure if i would ahve been able to get them both at 10 sec exposures.

gdheib0430: no, i didn't use neither darks or flats for this, nor any type of noise reduction on the camera.

About what you was wondering, if you need them or not with a normal camera lens, well, yes, and no.

Darks are not needed when you have long exposure noice reduction on, because then after you've taken the pic, the camera will automatically also take an equally long dark frame and add it to the pic. this can be good in some cases, like if you stack only like 20 frames or so. But if you're aiming for like 100 light frames, you need maybe only like 30 darks, and then it's much better to take them seperatly as it saves you a lot of time, and battery.

When it comes to flats, they are just as needed with any camera lens as with any telescope, but there is one exeption. And that is, if the camera have the lens data to remove vignetting installed, and then applies the data to the raw files. In my case, my camera have the EF50 1.4 lens data, and therefor flats shuoldn't be needed (in theory, lol).

About high ISO noise reduction, disable when stacking several pics, and enable when you take single pics... :)

post-22179-133877701523_thumb.jpg

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Just had a go at 135mm here the other day, but still really bad conditions. even worse then what i had before.

365 frames at 13 sec, ISO 6400. taken at f/5.6. total 1 hour 19 min.

Guess when it's this windy and stuff, and bac conditions, i guess a bright wide angle lens if the way to go. 50mm at f/2,8 turned out very good with less data then this at 135mm /f5,6.

Need longer exposure and lower iso for this to look good, but the 15 m/s wind was putting a stop on that option...

This lens also didn't give nice colors at all "wide open" (meaning f/5.6, lol), but at least the stars are somewhat round, even if they're not looking very sharp in my eyes. Might have missed flightly on the focus.

Wanted to try at 250mm in the first place, but well, yeah.. If i can't even hold it stable at 135, 250 would just be a waste of time... :)

post-22179-133877701705_thumb.jpg

Edited by Jannis

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nice pics! i know this is an old thread, but what about having the lens wide open stops the stars being round?

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Thanks for the replies :)

Unfortunally i don't think i have any pics at F/1.4 to show, but i'll see if i can take one later and show you how the stars look.

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Actually, i just found a pic at 1.4. it was sliiiightly clouded when the pic was taken, but the stars looked the same even when it wasn't clouded, so its a valid example still... :)

this is a crop from the middle left edge of the frame. the stars look a little better at the center, but not much... :D

post-22179-133877721688_thumb.jpg

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:) wow. i wonder why that happens?

thanks for posting!

Edited by 4lefts

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