slow progress

[niccodeamus]

These images have been stacked (about 8 fames except the M82 which was about 20) in DSS wrapped in a WineSkin on a Mac and processed in PS.  I am not too displeased with the Whirlpool.  M82 was a horror show, moon, movement, cloud, weird gradient going on (any suggestions on that, I have tried to sort of compensate but got bored).  the one frame is a RAW sub for the M82 stack, untouched.

i am still suffering horribly from the Frustration Mount, it has chosen to usually limit me to 15 seconds of exposure, so i am cranking the ISO to compensate.  Currently I am seeing no way round this, but I would like some advice and some information.

This is as i understand it.  For what I am trying to image, ideally I would have ISO 800 and 3 to 10 minutes subs on an f5 1200fl scope and build a stack of 50 frames.  currently I am stuck to 15 seconds and ISO (upto) 4000.  I wonder if someone could post for me a RAW sub from a similar sort of scope of the more ideal type of exposure and ISO and and example of the preprocessed stack and the processed stack to give me some sort of idea what goes on where.  I'd appreciate that.

A question about Jupiter.  it seems there is going to be a multiple moon transit this week and I'd like to have some idea what I am doing before then to try and get an image of some sort.  At the moment my canon DSLR refuses to take video on the telescope.  anyone know why that is?  I am guessing it is something to do with no recognised lens.  what route round it?  or have i stupidly not set something???

The image is a stack of 8 all done in PS.  I think it was taken with a 2x teleconverter.  I am thinking that if i can get some video on disk, then i can worry about computer work at a later date.

Any advice, gratefully received

nicco

[IanL]

Cranking up (or down) the ISO setting is not going to get you any more (or less) information in the image; it is a common misconception.  The only benefit of a higher ISO is when you are relying on the back of the camera display for framing/focusing since you'll end up with a brighter image to work with.  See here for the low-down:

http://www.blackwaterskies.co.uk/2014/01/do-high-isos-make-dslrs-more-sensitive.html

[Astrosurf]

Hi Nic (Nick??),

It's that mount which is the problem. Plus your long focal length scope on it. My 200P has an FL of 1000mm and, even with good polar alignment and guiding on my HEQ5 Pro (considered the minimum mount for good DSO imaging) I have to be gentle and there can't be any breeze.

The streaks in the 3rd image look like you have some light getting in there. Did you have a bright street light nearby? The circular gradient in the second is vignetting. I don't know if the plugin GradientXTerminator for PS will work on a Mac, but do some research. It's brilliant.

I'm not familiar with your camera, but are you set to manual? I'm sure someone with knowledge will be along soon.

You've done well regardless of the limitations of your kit!

Alexxx

[Astrosurf]

http://www.rc-astro.com/resources/GradientXTerminator/

There you go!

[Langy]

Regardless, you have still managed to capture some detail in there far beyond what a lot of us will ever get.

Well done and keep plugging away.

[Astrosurf]

You got the supernova too!

[niccodeamus]

thanks guys.  

while i understand that on a DSLR the ISO is artificial and I was/am using it in this knowledge, it is an interesting article and I will try using a lower ISO for the working subs and see if they come out cleaner - I am sure they will - but it is going to be a hell of a lot harder to see whether your target has wandered off or trailing horribly.   eeek

still hopeful of some posted images in the whole sequence so i can get a better understanding of what can be achieved from what starting point.

Alex, I cant remember what you said about the difference between achievable exposure time on the HEQ5 unguided and guided

[Astrosurf]

Alex, I cant remember what you said about the difference between achievable exposure time on the HEQ5 unguided and guided

It depends on how good your polar alignment is but I can get, unguided, about 30s towards the horizon and if I'm lucky about 45s towards the zenith, even a minute. Some people with my focal length scope get more as they're better at PA than me!

Of course, exposure times increase the shorter the FL you have.

[niccodeamus]

Hi Nic (Nick??),

It's that mount which is the problem. Plus your long focal length scope on it. My 200P has an FL of 1000mm and, even with good polar alignment and guiding on my HEQ5 Pro (considered the minimum mount for good DSO imaging) I have to be gentle and there can't be any breeze.

The streaks in the 3rd image look like you have some light getting in there. Did you have a bright street light nearby? The circular gradient in the second is vignetting. I don't know if the plugin GradientXTerminator for PS will work on a Mac, but do some research. It's brilliant.

I'm not familiar with your camera, but are you set to manual? I'm sure someone with knowledge will be along soon.

You've done well regardless of the limitations of your kit!

Alexxx

Im not worried about the vignette, the flats and other methods should deal with that ok, as you say.  the gradients from light ingress, i guess the moon was the source, certainly it was bright.  i think i will rig up a bit of a screen of some sort to help with wind and moon.

will your 600 take video mounted on the scope?

[niccodeamus]

It depends on how good your polar alignment is but I can get, unguided, about 30s towards the horizon and if I'm lucky about 45s towards the zenith, even a minute. Some people with my focal length scope get more as they're better at PA than me!

Of course, exposure times increase the shorter the FL you have.

guided?

[Astrosurf]

Yep, my 600D does video but not tried it yet. I started a thread here:

http://stargazerslounge.com/topic/208610-planetary-imaging-with-dslr-video-mode/

I recently did 7 min subs but you can do more if it's a very calm night and guiding works well. 5 Mins is usually safe for me!

[IanL]

thanks guys.  

while i understand that on a DSLR the ISO is artificial and I was/am using it in this knowledge, it is an interesting article and I will try using a lower ISO for the working subs and see if they come out cleaner - I am sure they will - but it is going to be a hell of a lot harder to see whether your target has wandered off or trailing horribly.   eeek

If it is a choice between using a higher ISO or risking losing the target, then go for the high ISO.  It is a lot easier when you use a laptop for camera control as the various capture applications will stretch the image for you on screen so you can see what is what, unlike the camera display.

[Russe]

Good first images!! +1 on the above mentioned comments!!

Keep at it and keep posting pics for advice!