astrophotography question

[eviltomato]

no i am not jumping the gun on wanting to take pictures!

I am just trying to get some info on it.

Am looking some pics on a site and am not sure yet what this info means...

Ha. 45 x 8 minutes

OIII. 18 x 8 minutes binned 2x2

Red. 33 x 2 minutes binned 2x2

Green. 20 x 2 minutes binned 2x2

Blue. 20 x 2 minutes binned 2x2

Total imaging time. 10 hrs 50 minutes.

Are these still shots with a long exposure time? And doesnt the earth rotate enough in that 2 minutes to blur the image? Or does the telescope track it during that 2 minutes?

I assume that filters were used in each one of the lines?

Then in the end it is all put into photoshop and blended together?

And does binned 2x2 mean that this was taken with binoculars with filters instead of a telescope?

hehe sorry for all the questions

I have a dob mount with no tracking.

[OutThereSomewhere]

For the sake of clarity on the answer, I've deleted my post as it was obviously wrong in a number of respects and would only lead to confusion!

[dmahon]

They're not videos, they're stills with long exposure times. There are various shots taken with various filters, which are then put together to create the final image.

Eg. Ha 45 x 8 minutes = Hydrogen alpha filter, 45 shots of 8 minutes each.

Each set of images is processed with softwware to prduce a master image for that filter, and then they are all put together in photoshop to create a final image.

[David010167]

Each is a filter. Example, red , green and blue are taken as separate shots and then combined to make a single image. Ha is Hydrogen Alpha filter, only lets through light in the wave length that is transmitted by hydrogen.

For example: Red. 33 x 2 minutes binned 2x2

means that a red filter was used to record only light in the red wavelengths. 33 images (photos) each 2 minutes in length were taken and then combined into a single frame. Binned is taking a number of pixels and reducing them to a single pixel to increase the sensitively.

It is not video, it is number of single exposures that are taken and combined.

regards

David

[dmahon]

And yes, the Earth does rotate enough to blur the photos, but the equatorial mount has motors which allow it to track the stars and prevent this. For long exposures, the tracking is usually corrected (or "guided") by a second camera, called a guide camera.

[OutThereSomewhere]

David and dmahon, Having read your posts I've obviosly got the wrong end of the stick on CCD imaging, so I've deleted my inaccurate answer and I'll now get my coat!

[eviltomato]

videos? lol where did you guys see that in my post.

Thanks for the info guys. Would i need to buy a whole new telescope or could i eventually junk my dob mount and put it on a motor driven tripod?

I have the skywatcher 8xt classic

[dc509]

If you really want to get into astrophotography, I would recommend the excellent book "Making Every Photon Count", written by a SGL contributor (Steve Richards - Steppenwolf). Certainly explained all the jargon to me when I first started getting into it. Beginners guide to astro-photography

d

[ollypenrice]

Yes, if you want to get into imaging it is usually best to start again, (sorry!) but do begin with Steve's book.

Olly

[eviltomato]

Oh i am definitely not getting into imaging yet. I was just curious what all it would take to get into it.

I am super green right now.. only been using a telescope for about 3 days now.

I think the next thing i will be purchasing is a wixey. Will also need to figure out how to make and mount a setting circle.

Got a good list of books from these posts now

[RobH]

Have a look on my website at the section called 'primers and tutorials'.

I've tried to explain all of this as simply as I can, while keeping all of the important info you need.

Middlehill Observatory, Dorset UK. The Astrophotography of Rob Hodgkinson.

Cheers

Rob

[eviltomato]

I was looking at your pictures and thats what sparked my interest in the first place.

Will check out your guides.

thanks!