Pelican Nebula

Emission Nebula in Cygnus, next to North America Nebula. It's sort of round, about 1° across. Hydrogen is ionised by massive UV radiation from hot, young stars.

We see it as it was in 200 AD, as it's about 1800 ly away.

24 x 120" ISO 400
60mm refractor, 370mm focal length, f/6.2 (flattener)
APS-C on EQ6 unguided

nice work, I'm twisting my head trying to see the Pelican in there....

Well, to tell you thé truth, I'm not too sure where the pelican is.

What's the problem seeing it ? I see it , just faint is all but it's definitely there . I also see the N.A. next to it . The only problem I see is you used 400 ISO and with this type neb you should use at least 800 ISO or higher to grab more data in short exposures . F/6 and 400 ISO is just kinda slow collecting . Perhaps you can re-stretch or someone else can bring out the Pelican a little better . Other than that , good job . You can BTW add more data to this image .

High ISO would bring out more nebulosity, but stars would become indiscriminately white. I found that ISO 800 on 1min exposures already removes all colour from the stars.

What info would you like to have on the photo? I'll gladly add it.

Here-s the annotated version:]

In the past when DSLRs' were starting to get popular for astrophotography the trick to getting a good image which included star colors was to take a certain amount of exposures at 400 ISO , another set at 800 ISO and if needed a few at 1600 ISO then stack all images for editing . However the higher the ISO the shorter the exposures were but it was recommended a minimum of 2-min per exposures and up to 5-mins per exposure . However also to do this the camera had to be on some type of tracking platform . This cannot be done from a regular tripod . Color is preserved in lower ISOs' with shorter exposures but it takes so many to stack to bring out the signal (data) which is the reason for using higher ISOs' . But also too depending the scope used and mount for tracking are all factors to a good image . If your going to continue to use only 400ISO then you need about 100 good exposures for stacking to really bring out good data for really good images . That's why I mentioned you can add data to the image above to bring out a better image .

The different exposure times to preserve color is a very good idea, I'll try it. I do this for objects that have too high a dynamic range, but haven't tried it for color before.

100 frames you say... hadn't realised so many were necessary. I am tracking with a EQ6.

*add more data* - funny :P.

ecce_lex wrote in post #16137342
The different exposure times to preserve color is a very good idea, I'll try it. I do this for objects that have too high a dynamic range, but haven't tried it for color before.

100 frames you say... hadn't realised so many were necessary. I am tracking with a EQ6.

*add more data* - funny :P.

Data = https://en.wikipedia.o​rg/wiki/Data

Signal = http://en.wikipedia.or​g …l_(electrical_e​ngineering)

Data and Signals = http://highered.mcgraw​-hill.com …7/student_view0​/chapter3/

http://www.computerhop​e.com/jargon/d/datasig​n.htm

Data = Signal = Images