The great SMC experiment

[middy]

A couple of weeks ago I posted my widefield attempt at the SMC (39 stacked images, you had to squint to see it). I set myself the task of collecting 100+ images to see what difference it made to the outcome.

So after a gruelling total of 3 nights taking ~40 x 64sec images each night. I present my final image of SMC. I refuse to take any more shots of the SMC. I am like so over the SMC.

123 x 64 secs, f4.8, ISO 400

The original shot of 39 stacked images is also presented for comparison .....

[janoskiss (Steve H)]

Not a bad start but I think you need more shots! But longer exposures as well! I assume you're stacking so many short exposure frames because you don't have a tracking mount...?

Unfortunately digital cameras have what is called the "noise floor" which sets a lower limit on exposure time for single frames for a given scene. If you go below that limit, you get virtually all noise and no signal, and stacking won't help, because you'll be stacking mostly just noise on noise, and just getting more noise in the end result. What this means is that you cannot substitute one long exposure with multiple shorter ones unless the short ones go well above the noise floor.

Bert is our resident SMC master! He can tell you how it's done!

[middy]

Originally Posted by janoskiss

Not a bad start but I think you need more shots! But longer exposures as well! I assume you're stacking so many short exposure frames because you don't have a tracking mount...?

Actually, I'm stacking so many short exposures because 64 secs is the maximum exposure time of the camera.

Now if that is not a case to buy a 350D then I don't know what is.
I must do everything the wife asks me from now on.
I must do everything the wife asks me from now on.
I must do everything the wife asks me from now on.
I must do everything the wife asks me from now on.
Naahhh, I'll just make do with the camera I have.

[sheeny (Al)]

I admire your perseverance, Andrew! Looks like you're are really stretching the capabilities of your camera!

Al.

[xelasnave]

Andrew wonderful effort, I remember the frustration of not enough seconds in the camera... LPI effectively 100iso 16 second limit was my max for a long time and latter a hand held with iso 400 and 15 seconds.. The 300d was like being used to a horse and cart then jumping into a F1 racer. It is nice to see that you are concerned about spending joint savings (credit) on only one family member it is nice to see that respect for ones partner.
You must be able to get a second hand 300d real cheap now and it will blow you away the ease of getting good wide fields.
But before spending money on a camera I would suggest you think about the mount side of things, not only will you need an equatorial mount but a good one, a good starting point is a eq6 (approx $2000) but go to $10,000 if you want, even more..and there is a message there..the mount is it when it comes to astro photos.
Personally I think with your current approach there is more you can do and I recon the more frustration you can get done before you spend big cash on mounts and camera the better.. I mean what you have done is very impressive on a DOB that must give you much satisfaction if not it should..great effort
alex

[janoskiss (Steve H)]

There is always 35mm film! There is an absolute bargain of a Pentax film SLR in the Buy & Sell thread.

[avandonk]

With so many images it may be possible to try summing pairs of images for a start and then stacking and median averaging the stacked pairs. This would be the equivalent of doubling your exposure. It is better if the pairs are far apart in the exposure sequence. This is where any slight drift is an advantage as you are adding noise from different parts of your sensor. This will tend to even out any noise present.
first pair exp 1 and 50
2nd pair exp 2 and 51
3rd pair exp 3 and 53
and so on.

If this works then try by summing lots of four and then stacking and median averaging. This will be the equivalent of four times the exposure.

The LMC is very difficult to get a decent image as the contrast is very low. We all start somewhere. Your image is far better than my first attempts.

Bert

[Lee]

Nice image considering Andrew.....

[xelasnave]

And Andrew there would be many objects that you may bag this way, bright clusters maybe..and a 35mm is a great idea I got one but never used it cause the 300d came along... but you still have the mount to consider
alex

[middy]

Originally Posted by janoskiss

There is always 35mm film! There is an absolute bargain of a Pentax film SLR in the Buy & Sell thread.

Thanks but I already have a 35 mm film camera gathering dust in the cupboard. Minolta 7000 anyone ????

[middy]

Originally Posted by avandonk

With so many images it may be possible to try summing pairs of images for a start and then stacking and median averaging the stacked pairs. This would be the equivalent of doubling your exposure.

Thanks for the tip, I'll try that.

[middy]

Thanks for all your advice and kind words.

Originally Posted by xelasnave

You must be able to get a second hand 300d real cheap now and it will blow you away the ease of getting good wide fields.
But before spending money on a camera I would suggest you think about the mount side of things, not only will you need an equatorial mount but a good one, a good starting point is a eq6 (approx $2000) but go to $10,000 if you want, even more..and there is a message there..the mount is it when it comes to astro photos.

Second hand could be the way to go, I'll have to check out that well known auction site. I can't foresee any way I would ever be spending $2000 on a mount .... maybe if I win big on the lotto.

Originally Posted by xelasnave

I mean what you have done is very impressive on a DOB that must give you much satisfaction if not it should..great effort
alex

The only things I have photographed through the Dob are the moon and Jupiter. An EQ platform is on my list of things to build one day. Any non-solar system image I post has been done on my two bits of wood hinged together StarTracker