Question about HDR

[viktorcech]

hello, i new user from Slovakia. Pixinsight is very usefull software for me. I using now only trial version, but i would like buy full version..
I have questions about making HDR..

1.  in menu Script/Utilities i dont see HDR script. where can i find it? i have hdr.dll on program files (windows 7 original)

2. in tutorial is written abou 2s,10s,2min,10min,30min exposures.. what is that? its 10x2s,10x10s,10x2min,10x10min,10x30min or only 1x2s-30min exposures? thank you.. sorry for my english

[Nocturnal]

Hi Victor (I think that's your name, if you sign with it we can address you properly),

I see the HDRComposition script under the utilities menu. On my machine it's in this directory: C:\Program Files\PixInsight\src\scripts

When you stack multiple exposures of the same length the signal to noise ratio improves but the dynamic range does not. So the example makes no assumptions and no recommendations about how many sub exposures per exposure length you need. You need to figure that out yourself. It only contains an example of an exposure length mix to capture a large dynamic range. To be honest the suggestion seems a bit over the top for me when you use a camera with 20K-30K wells and a 16b ADC.

If these concepts seem strange to you perhaps you should not dive into HDR right away and do a few more pictures with just 1 exposure length first.

[georg.viehoever]

- The HDR script has been replaced by a full process some time ago, see Process/Image Integration/HDR Combination
- You should stack the different picture sets you have before doing HDR Combination. Which times are useful is a depends on the object you are imaging, but having a factor 4 or 8 between the different image sets is probably a good idea.
- Using the search function of the forum, I found this http://pixinsight.com/forum/index.php?topic=2320.0 with more information . It is always a good idea to use the search functionality of the forum.

Georg

[Nocturnal]

Oh, I forgot about the process. Thanks Georg!

[viktorcech]

Thanks all for fast reply, now i see that HDR window.. You know, im newby in astrophoto. I learn it maybe 24 months - 22 months only from tripad and small exposures like this:




2 months ago i buy EQ3-2 and i want modify my canon eos.. now i using DSS for stacking, i take example.. 15x240s lights,15x240s darks, bias, flats and stack everything in DSS..

in pixinsight or DSS i only stack this different 2s-30min exposures? with or without dark frames? this is only that i dont understand, if i must use dark frames, or only use hdr script in pixinsight? thanks.. sorry for stupid questions :/

[Nocturnal]

Hi,

you can ask anything you like but you may not always like the answers

I think you should get single exposure length pictures under control first. There is no need to jump into HDR just yet. It is not the critical thing that will magically produce better pictures.

- improve your acquisition so your stars are round
- take lots of subs of the same length
- learn how to properly stack them with bias, dark and flat frames in DSS or PI (I prefer DSS because it's easier, I recommend that for you too)
- learn how to process the resulting image in PI

Then when you're bored with that let's try doing some HDR.

I've been doing this for a few years and only shoot the Orion Nebula in HDR and then only 2 exposure lengths. There are plenty of other targets that don't require HDR.

[viktorcech]

Hi,

you can ask anything you like but you may not always like the answers

I think you should get single exposure length pictures under control first. There is no need to jump into HDR just yet. It is not the critical thing that will magically produce better pictures.

- improve your acquisition so your stars are round
- take lots of subs of the same length
- learn how to properly stack them with bias, dark and flat frames in DSS or PI (I prefer DSS because it's easier, I recommend that for you too)
- learn how to process the resulting image in PI

Then when you're bored with that let's try doing some HDR.

I've been doing this for a few years and only shoot the Orion Nebula in HDR and then only 2 exposure lengths. There are plenty of other targets that don't require HDR.

sorry, i know this techniquies (dss, darks, flats, bias, long exposures).. i have eq3-2 and i now taking 5-6minutes with 100mm - perfect rounded stars..



my first testing was 120minutes lenght.. but youre right, i must training basic proccessing and then try hdr.. but important! is modded dslr.

but hdr is nice..

[Nocturnal]

but important! is modded dslr.

Why is that important when discussing HDR?