Why the lack of contrast?

[Nerf_Caching]

Hi all,

I've been struggling recently with getting my nebulae to pop out in a single sub for a certain rig that I'm using. I wonder if it has to do with the filter in my imaging train, as I've got no problem using a different telescope configuration. Attached are two subs to show what I mean. 

The first pic was using an Evoguide 50ED, a generic UHC filter and a ZWO ASI585MC Pro camera. Sub length is 30 seconds at gain 252, cooled to -10C

Second pic used the same camera and shooting settings, but with an Evostar 72ED and Askar Colourmagic Ha+OIII filter.

Both shot under bortle 9 sky, same object.

Clearly the second pic pops out way more, so I don't really know what the issue is?

Kind regards,

Ronald

 

Edited July 21 by Nerf_Caching

[Elp]

Two things.

The UHC is a general LP filter so will only block out so much LP, it will also likely block some signal in the process. The colourmagic ha+o3 will block pretty much most other than the permissible bandpasses from manufacturing so allows ha and o3 bandpass light through. So for emission targets rich in ha and o3 they'll pop out from the background sky when taking images because the filter has blocked out everything else you don't want (IE LP). Some LP will seep through, this is why people buy narrower bandpass filters to tighten up permitted signal closer to the required gasses.

Two, the larger aperture scope lets in more light than the smaller one, it is also imaging at a longer focal length so your resolution will be better (more detailed).

[alacant]

57 minutes ago, Nerf_Caching said:

second pic pops out way more,

Hi

We prefer UHC to the narrower filters. Put the UHC on the 72 and I think you'll be pleasantly surprised.
Cheers