First Image, think im on the right lines ?

[johnb]

Hi

so here is my very first attempt, at a widefield star shot

Im using a Sony A350a and a tripod (no telescope)

Lights - 10 Exposures at ISO800, F4.5, lens set to 18mm, exposure of 30 seconds, i had to discard 5 as they had planes and cloud so ended up using just the 5 in DSS.

Darks as above and i used 5 shots

In DSS its selt i used the defaults and have done no processing after its registered and stacked

I noticed that some of the lights I discarded had no score /, is there an optimum score one is looking for ?

I noticed when DSS when thorough the process and registered each shot it found around 50 stars on the first and each subsequent shot had more and more.

Anyway looking at a singel shot and then the finished product as in 5 stacked and the image processed by DSS there is a lot more to see in the final image, there is probably not much to comment on, however all feedback welcome.

Regards

John B

[Andi Turner]

Looks good to me! I had one of those cameras, the live view was a blessing!

Next job would be to adjust the levels in your 'photoshop'. Try dragging the upper and lower arrows on the levels to fit snuggly around the histogram and then have a play with te middle arrow, it should bring out a load more detail.

[Aza]

Clouds are one thing, but if you have satellites etc, you dont need to discard those. Choose sigma clipping for the stacking method, and it will remove those automatically.

Regarding scores...use all subs that score more than half of the highest scoring sub.

The stacked version from DSS usually needs quite a bit of further processing.

Do you have Photoshop?

Also have you been taking your subs as raw?

[tinvek]

good first attempt, very similar to what mine was (also using an A350 )

one little tip, if you use it in jpeg mode rather than RAW whilst focusing you can use a 2X zoom on the live view which helps.

one bit of good news, if (when ) you buy a telexcope, the A350 doesn't need the focus travel to be so far in as for example a canon so you may avoid the focusing problems on some newts, certanly my A350 focuses ok on my skywatcher 150. one bit of bad news, watch out for pretty severe amp glow if you try and take lots of exposures back to back with no time between them.

A350 isn't best camera for astro work (fantastic terrestial camera, love mine ) but it can do a good job on the end of a scope, especially on the moon, i took this single image a while back and did a little bit of processing to lift the colour

http://stargazerslounge.com/imaging-lunar-solar/76678-last-nights-moon-again.html

there's a link to the full size image in the thread

EDIT: here's the original in jpeg without any processing

http://stargazerslounge.com/imaging-lunar-solar/76647-quick-moon.html

[johnb]

Thanks for the feedback, to answer the questions ive being asked

1 - Yes taken the pics in RAW format

2 - I dont have photoshop yet, but will have shortly.

I see that DSS has some functionality for adjusting RGB etc but I do find the concept a bit confusing, i see suggestions like get the levels to fit the histogram but despite reading the various tutorials im still confused, below is how DSS shows the stacked image, i can see that by moving the sliders (RGB) i can change things but im not sure what im attempting to achieve (sorry for all the questions)

Regards

John B

[Aza]

In the image above it shows that the colour balance is out.

Those 3 coloured peaks should all be aligned.

However, DSS can fix this automatically while stacking:

After clicking 'Stack checked pictures' in DSS, click recommended settings.

In that section you can scroll down and ensure you use the option that says:

"If the colour balance in the resulting image is hard to fix......."

The trouble with DSS is that the output image is always very dark, and not really the true image you have. You need some software to adjust the levels and use curves to stretch the histogram to reveal whats hidden there.

[johnb]

Thanks

Thats made a huge difference, the coloured peaks are now all lined up, the image its self is greyer but already has so much more detail. from what your saying thats probably about all i can do with DSS and now need to move onto another package for post processing ?

Regards

John B

[Aza]

Yeah I would say so.

There is a free program called GIMP.

Its not ideal as you can only work in 8bit, and for astro use 16bit is preferable.

However you can at least use it for now and start practicing on levels and curves