Second night of imaging with EOS 350D

[JohnG (John)]

Hi all
I am new to the group and thought I would post my second attempt at imaging with a Canon EOS 350D. I have been observing for a lot of years now and thought it would be good to get back into imaging in the digital age.

Taken through a Takahashi FS-102, f/8 prime focus, taken on 2 Jan 06, seeing about 6 on the Pickering scale.
1 x 4 second at ISO 800
6 x 20 seconds at ISO 1600
Stacked with Registax and slightly tweaked with Photoshop 7.

Comments and critical remarks gratefully accepted.

JohnG

[h0ughy (David)]

Excellent Image John, you have brought out the whispy nebula and the dark lanes, but the detail in the trap area is a treat. have you gone any longer with your shots? perhaps to bring out more external details of the nebula?

[JohnG (John)]

At the moment I am limiting my exposures to 30 seconds maximum until I gain a bit more experience, this all very new to me, I was used to 35mm film. The 4 second exposure bought out the Trapezium stars nicely and they fitted nicely into the burned out area on the 20 second exposures. Focus still needs to be tweaked a little, just not quite right yet.

JohnG

[Dennis]

Hi John

That is a wonderful image with lovely detail. One thing I noticed immediately, the background was very black, almost too black? Most other astrophotos I see have a more "natural looking" dark greyish background, which I understand means that you may have clipped data by setting the black point too high in the histogram?

Cheers

Dennis

[JohnG (John)]

Thanks Dennis, that's the sort of information I need, I am just starting down the digital road, getting the hang of Photoshop isn't easy.
Thanks
JohnG

[Itchy]

Hi John,

Welcome to the group .

Great work for your second image, well done. Dennis is right, the histogram of your image is fairly severely clipped, with over 67% of your pixels registering as 0,0,0 (black). Although sometimes this can make an image look "clean", it means that any data in those pixels is now lost forever. When using photoshop, always keep an eye on the histogram. It should begin at zero on the left and then rise to a peak (where most of your data will be), and then tail off to the right. As soon as you have a lot of pixels on zero or on 255, it means that you have lost some data.

Also, hOughy has alluded to the other thing to do. Increase your exposure time. The longer exposures you can achieve, and the more subframes you can stack, the better your images will become (unless you are capturing very bright detail as you have done here). Why have you limited yourself to 30 sec? Most well aligned mounts will give you at least 1min unguided.

Also, are you using jpeg or RAW? RAW(converted to 16bit tiff) is better.

Anyhow, there is lots to learn and here is a very good place to do it. Keep asking questions and keep taking images!!!

Cheers