RAW/FITS Settings

Hi Frank,

No problem at all 😉 very good question actually!

• The debayer algorithm AAD will be best to use. If you were the use bilinear, you will certainly see that the image will be less sharp 😉
• The debayer pattern is found automatically for your camera
• regarding the R,G,B sliders, this enables you to do white balance yourself if you want to do it. But my recommendation would be to leave it at 1,1,1. The reason is that, the values of 1,1,1 will let you work with the raw intensities of the data recorded by your sensor. If you use the multipliers, for instance 1.5 , 1 ,1.8 then you will immediately throw away data on the right side of the histogram, which could lead to more burnt-out stars and less color in them. The color of your background and the stars can be calibrated perfectly after the integration task without throwing away data to start with 😉
• So I would also recommend not to use the camera white balance for the same reasons. Besides that, it's also the question of: if a white balance value of your camera is usefull for our astronomical data processing purpose. The white balance value gives good colours for daytime photography, which uses a non-linear sRGB or Adobe 1998 colorspace usually. The steps needed to convert the raw data from linear with multipliers 1,1,1 to non-linear sRGB/Adobe 1998 are completely needed to have the white balance setting making any sense. Our data processing isn't using all these steps, we don't convert the data to the same non-linear (log conversion) state, and we don't create a sRGB/Adobe1998 colorspace. So using a white balance setting is, in my opinion not very usefull to start with.

So my suggestion is to leave everything at default, I always process my own DSLR with the default settings. I do know however that there is quite some debate on whether to use white balance or not, so it's there if you want to try it. And you can even set it yourself if you want 😉

I do consider leaving the multipliers at 1,1,1 and not using camera white balance, best practise. I think it's best to work with the full raw linear data without any alterations.

my M101 😉 from last year, processed with defaults:

42x15minutes

iso 320

Nikon D5100 BCF mod

Takahashi TSA-102 with TOA 0.7x reducer

Cheers,

Mabula

Thanks a lot for the detailed reply! Stunning picture, I love the colors from the Takahashi! Way to go for my little Newton 😉

Thank you Frank,

It's a very nice region to image with longer exposures and total integration times, lots of small and faint galaxies in the background 😉 Show me your M101 when it's finished!

Cheers,

Mabula

Hi Mabula, 

it is indeed a great region, actually just through your image I noticed the small/medium galaxy at the bottom. Wow what a difference your scope and the longer exposure times make. It is just a yellowish blob on my image:

So yes a quite noticeable difference 😉 But given I only had 6 * 300s and 9 * 600s subs and that we had full moon I am quite pleased with the result.

I just sent my only four week old Bresser Exos-2 mount back to the dealer and hope to trade it in for a HEQ5, so maybe I can take longer (and more) exposures soon to get more details...

Have a good weekend!

Yes indeed, I see it.

If you make your background very dark, it will be more difficult to see the faintest signals. But this is also a question of taste I think 😉

Oh, that's good to hear, the HEQ5 has proven to be a very good mount with good capacity. I am sure you'll improve your exposure lengths with it!

Clear skies Frank, have a good weekend 😉