Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

IC 1805 The Heart Nebula

Jonk

By Jonk
in Imaging - Deep Sky

Recommended Posts

Jonk

Jonk

Posted
Posted

Here is my first attempt at the Heart Nebula.

It was 100 minutes in total, with 20 x 5 minute subs at iso1600, including darks, flats, bias etc.

Guided using PHD (I'm getting better!), camera was Baader modified 1100D with Astronomik clip filter, scope was 150p reflector on an HEQ5 pro mount..

Heart Nebula

I'd like to know why so grainy? One thought I had is temperature noise. The 1100d can set mirror lock up (essentially live view) via APT, to avoid mirror shake at the beginning of the exposure.

The problem with this is the lcd stays on with a counter, presumably causing lots more heat than desired.

What tips can people give for lower noise, longer subs apart from temperature?

They're nowhere near as sharp as other DSLR users' photos I've seen, so what am I doing wrong?

Link to comment
Share on other sites
DanL

DanL

Posted
Posted

My two cents... Try dropping the iso to 800. High iso is more sensitive but will introduce more noise. Also, in the menu functions there should be an option to turn off the lcd picture preview - at least in my old 350d there is - so I expect there is something similar in your camera. Also, the more images you take the better your signal to noise ratio will be and that will help clean up the final image. [emoji4]

Link to comment
Share on other sites
StargeezerTim

StargeezerTim

Posted
Posted

I think it is a good result. I took the same scene as you with same iso and got a similar result. You can reduce grain with noise reduction and boost colours. You could also try using a UHC filter as well as, or instead of, your light pollution filter. If you lower the iso, you will need longer subs to get the same data, as far as I am aware. Hope you don't mind, I had a little play, just boosting colours through LAB colour and using the NR filter in photoshop. Nice image.

post-35654-0-00502900-1445951003_thumb.j

22313557669_9b30c7bb01_ha.tif

Link to comment
Share on other sites
Jonk

Jonk

Posted
  • Author
Posted

Thanks for the comments!

Yodda - the lcd will not switch off pressing disp, I have tried many times with no luck!

I have tried a different approach to processing this, by using FITS liberator and RGB editing in photoshop, rather than lightroom.

Here's the result:

Heart Nebula

There's too much noise still, but I'm still learning so can live with it until I figure out how to do it better with what I have. I will try lowering to ISO 800 to see how that helps, and may even get a UHC filter as I probably want one for visual anyway.

So apart from more data and less aggressive stretching, how else can I reduce the grainyness and improve the sharpness?

I've been reading up on deconvolution, but apart from IRIS (which is command line based) is there a free (not demo) software package around that's easy to learn and will at least provide an improvement?

Link to comment
Share on other sites
Jonk

Jonk

Posted
  • Author
Posted

The key is to press it after the connection is made. As I know this trick works for all models except 1200D...

You mean after APT detects the USB connection, or after an exposure is started?

Link to comment
Share on other sites
Jonk

Jonk

Posted
  • Author
Posted

Just tried it (APT 2.90) - pressing DISP on my 1100D after connecting to APT (in M mode), brings up all the exposure settings on the display.

Anti-vibration turns the display off, then when the shutter is open, a timer appears.

No matter when in that sequnce I press DISP, the timer is still there, hence LCD on.

Is there anything I can send you to see why? Logfile?

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.