any tips for 7nm ha?

[blink138 (Pat)]

hello members a couple of things
since the moon is up i would like to know of any decent ha targets for me to practice on
secondly what sort of exposures and what would the dslr histogram supposed to look like for an ha shot
an apm 107 with reducer
regards
pat

[multiweb (Marc)]

Originally Posted by blink138

hello members a couple of things
since the moon i up i would like to know of any decent ha targets for me to practice on
secondly what sort of exposures and what would the dslr histogram supposed to look like for an ha shot
an apm 107 with reducer
regards
pat

M8, ngc2070, m42, ic434

Depends on your target but I'd say at least 300s subs. Histogram will be no different than an rgb shot.

[blink138 (Pat)]

thanks marc........... i did not think there was anything in the middle ha ha!
m8 et al go down early and m42 does not clear my roof til after midnight (bugger)
i think i will just have to wait for the galaxy to rise in the east and clear my roof
thanks again mate
pat

[multiweb (Marc)]

Have you tried all the stuff in vela ? Could be wrong but I think it's up ahead now?

[blink138 (Pat)]

ooh now that is a fab suggestion monsieur multiweb!
great idea mark! (still sunny in perth ha ha!)
pat

[Andy01 (Andy)]

The Helix, Tarantula and it's LMC friends are rich in Ha and currently in favourable position.

[blink138 (Pat)]

they are andy but i have a great naffin big tree on the next property which cuts my lmc/smc fun!
the helix is a goodun' though but my fast apo may not give me much detail
pat

[White Rabbit]

Try the tarantula with 600 sec subs. I never shoot less than 600 secs with Ha.

[MrB (Simon)]

Hi Pat,
I think I might have mentioned this before in another thread, but do not trust what the 'white' (RGB) histogram tells you. It is an average of all three channels so is not a correct representation of the exposure for Ha. Press the 'info' button one more time and look at the red only channel in the split histogram.

The images below will show you why.... The RGB histogram in the first image looks underexposed, as its peak is just under the 20% marker and we should be shooting for around the 33% mark.
However, looking at the red only histogram in the second image... Oh dear, we are overexposed with the red channel peaking around 50%.
The highlights in this image were blown-out, but I was attempting to catch some of the fainter outer regions with this shot.

Apologies for the dodgy camera phone pics

[blink138 (Pat)]

ah simon that is what i needed to know, thanks mate!
does not look like anything will be happening tonight ha ha!
pat