milky way with standard canon 18-55mm lens?

[happy-kat]

Take darks deffinately. Just put lens cap on and another 10 subs all same settings.

Make sure in camera noise reduxtion is off

[Gerhard]

Will do! I hope tomorrow I'll have some clear skies... the forecast seems ok...

[happy-kat]

If you take photo with no foreground take loads of subs for stacking later. The more you take the more data you will have. Nail that focus!

[Knight of Clear Skies]

Good! because, as I said, flats would be kind of a problem from where I will be shooting. 

Do all you guys have custom made flats filters? cut out lens caps with white cloth / paper across it?

@Knight: I'm guessing you have a motorized mount for those long exposures? I will not be going over 20 - 30 secs for a sub... otherwise trail-fest...

Yes, taken using my EQ3-2 mount.

For flats, one method is to use a laptop or computer screen as a light panel. If you set the camera to Av (aperture priority mode) the camera should sort out the exposure length for you.

Take darks deffinately. Just put lens cap on and another 10 subs all same settings.

Make sure in camera noise reduxtion is off

Good point about turning off the in camera noise reduction - it's useful if you are just taking a single shot but it wastes valuable exposure time if you are stacking.

I disagree about the importance of taking darks, they may not make any difference to the final image quality. Reading up on the theory I don't believe darks will help with exposures under 2 or 3 minutes as a rule of thumb (depending on the temperature). Treat my words with a little caution here, I'm not certain about this.

I've tried taking darks and they didn't make any noticeable difference for me. Imaging is all about signal-to-noise ratio. Taking more lights will always improve SNR - if it's a choice between taking darks and lights I'd be inclined to go for the latter. If the darks can be taken without impacting imaging time then by all means give it a go.

[VigdisVZ]

Don't bother with calibration frames when shooting wide field

[happy-kat]

If there intersting foreground try 18mm 25 or 30 second single shot.

If good in photoshop try layering your foreground on.

Take lots have fun.

[happy-kat]

There was an awsome isle of wight single milky way shot with cracking foreground

[Gerhard]

ooo, another new term (or maybe a synonym?): calibration frame!! is that a term to signify darks, bias, and flats in one word?

in the initial first response to this thread 50x20s was mentioned. I was going to go for that. Do those first, and afterwards do the darks and bias anyway. It wont' hurt, and it's better to have them and not need them, than the other way 'round...

@Knight: good suggestion about the laptop screen for flats. I was just wondering: it seems flats should be taken in exactly the same setup as the lights, with focus, etc... As I already mentioned, I will not be able to do those in the same location as where I will be shooting... Not now, for the milky way, but as well for DSO shooting, later on when I'll have my telescope...

I could maybe use a tablet... put the flashlight app on it, and tie it up to the front of the camera / scope somehow... without moving the optics, focus, etc...

Have to figure this out, but maybe for wide angle shooting it's not yet such a big issue...

[Marky1973]

Gerhard - with regards your question about flats I made my own solution which you can see in this thread.

http://stargazerslounge.com/topic/227341-flower-pot-flats-the-test/?hl=%2Bflowerpot+%2Bflats#entry2449850

I am still experimenting with it and it is a work in progress (need to play with the brightness) but it seemed to have a positive effect on my first attempts. Might be worth a go if you are on a budget - for when you move on from widefield imaging!

[Gerhard]

Marky, can you read minds??? I have been looking for that thread this morning, but couldn't find it anymore, and was already flogging myself for not having earmarked it!! :-)

thanks a bunch! :-) Will definitely consider this, if the tablet flashlight method proves bogus...

[VigdisVZ]

ooo, another new term (or maybe a synonym?): calibration frame!! is that a term to signify darks, bias, and flats in one word?

Yup!

[Gerhard]

Thanks for clearing that up and adding to my knowledge!! :-)

I will do the darks and bias anyway, if not for anything else, for practice! :-)

It will be my first time round seriously trying to capture some night sky... 

[Marky1973]

Gerhard, you are welcome.....and I think the key is to just have fun experimenting - don't get too stressed trying to get everything right first time. Just relax, enjoy what you are doing and learn from your mistakes. I;ve been out and spent 3 hours shooting all my frames, only to get them into DSS and find out that, ultimately, they are a bit rubbish. BUT, the process that night taught me a little bit more about how to make it better bext time....have fun!

[Gerhard]

Marky, you're not calling those Andromeda pics from the flower pot thread rubbish, I hope??

I would be dancing the can-can if I managed a shot like that!!! (trust me, you do not wanna see me do that... ;-) )

[Marky1973]

Thanks for the kind words Gerhard - well no, they are not rubbish, but the ones I did after that were a bit ropey - and they are still leagues away from what some people get. But, if I showed you my very first attempt you would see how quickly you can progress with the minimum of kit. And they were taken with a modicum of set-up and polar alignment, but I didn't stress myself out trying to get it bang on - I'm saving that for when I go on to bigger things in a year or two....and have to drive myself mad to forget how much it all cost me.

[Gerhard]

Just to know: what do you call "minimum of kit"? I remember your post vaguely, and if I'm correct you don't have coma correcotrs, Ha / OIII filters, and so on, right?

Just your out of the box telescope with mount, aligned and motorized, right? Barlow lens? what eyepiece did you use for the andomeda?

[Marky1973]

I have a Starwave 70ED mounted on the EQ3-2 with an added RA motor (you don't need DEC motors for the EQ3-2) and then the Canon 1100d plugged into the scope via a 2-inch extension tube connected to the camera with a T-Mount. USB cable to the laptop. Oh and the polar scope comes separately as well. No filters or anything. I will look into some light pollution filters and a field flattener (I think these are kind of the equivalent of a coma corrector but for refractors!) another time, but that is all I use at the moment. No barlow or eyepiece in between the camera and the scope for imaging - the camera is the eyepiece.

For visual I have 25mm, 17mm, 10mm, and 8mm eyepieces and a 2.25x and 1.5x Barlow (it's a baader two in one thingy) - but you don't need those for photography.

[Gerhard]

Yes, I wasn't thinking when I asked about the eyepiece... Of course when doing AP, the eyepiece takes a vacation.... :-)

The polarscope is just a way of making alingnment easier, am I right? You can align also normally using the supplied finder, no?

[Marky1973]

What do you mean by "the supplied finder" Gerhard? I don't think you can align successfully using the scope finder - you don't align the scope, but you align the mount. If you don't have a polar scope you can just remove the caps from either end and sight Polaris through the mount itself. If you get Polaris central in this "tube" you should be well enough away with some shorter images - I got up to 60 second subs okay. If you lean back from the hole in the back of the mount a little, you can get Polaris more accurately in the centre.

[Gerhard]

uhmm, I was under the impression that one can align any EQ mount using the scope to center on Polaris, when the scope is aligned with the mount. Otherwise any EQ mount sold without a polarscope would be useless, no?

A polar scope will make alignment easier and more accurate, I guess, but is not essential.... no?

Do EQ mounts have a tube one can look through?? If so, does anybody actually use this very crude method to align their mount??

[Marky1973]

I am sure you can align the scope to polaris for visual use, but I believe it would not be accurate enough for long exposure astrophotography - but I do stand to be corrected - I am a complete novice at this.

On the EQ3-2 - there is a hole for the polar scope. If you don't have a polar scope, you can remove the caps from either end of this mount and look through the hole. If you are pointing towards north and have the altitude set for your location, you should be able to tweak the alt/az screws to line polaris up in the middle of this hole. So you do not have to have the polar scope and you can sight-align the mount through the hole that the polar scope slips into......at least that is what i was doing before I got a polar scope!

[Marky1973]

This is what I mean - please excuse the crude arrows! :-)

I didn't have a rear white cap over the setting circles as I had a clearance scope - just remove that, and the black cap on the front of the mount and sight through that.

Again, that is what I have been doing - it could be completely wrong, but it stands to reason you can do that, if the polar scope goes in the hole you are looking through.

Hope this helps - it is a minefield trying to figure all this stuff out! :-)

[Gerhard]

Days ago I looked up how to align an equatorial mount, and came across this video:

How to Align an Equatorial Mount:

I had never heard of a polar scope yet... I guess it depends on how accurately you put the main scope aligned with the polar axis of the mount...

[happy-kat]

From my barn door stuff it is irrelevant where the telescope/camera points but it is essential to polar align the mount it sits on. It is the mount that combats the earth's rotation and for that it has to be aligned.

I expect you might get a much better clearer answer.

[Gerhard]

Yes, obviouslyit's the mount to be aligned, but as shown in the video, the main scope is used to establish that. Once aaligned, the scope can obviously be pointed atany object, and then followed by manipulating the RA axis... :-)

I was just unclear about the polarscope. hadn't seen one, hadn't heard of it, and didn't know some EQ mounts have a special "tunnel" for it...