Modern Full frame or (old) APS-C but modified?

I've just started doing a bit of astrophotography (with a Skywatcher Star Adventurer tracking mount, DSLR and lens, no telescope yet).

I've got a 5D4, which is obviously great for wide field of view shots, but in the main I want reach. I have an old 7D (mark I) and I'm wondering if that would make a better choice?

An APS-C crop from the 5D4 is approx 11.5MP (vs 18MP for the 7D frame). Obviously the sensor on the 5D4 is much better than the 7D. However, a CLS filter (https://www.wexphotovi​deo.com …0G4wd-EAQYAiABEgJhefD_BwE) looks to make quite a difference (https://www.altairastr​o.com …/D/Orion_nebula​-L-Pro.jpg ), but is only available for APS-C bodies.

Additionally, there's a (reasonably) local company to me that will remove the rear UV/IR Cut and Colour Correction filter from the 7D, for which they claim:

"...removing this filter we can massively improve the camera's red response by up to 4x in the all important Hydrogen Alpha band.

This greatly reduces the amount of time needed to capture those wispy diffuse nebulae, but also brings out more detail in every other astroimage you will take"


So... despite the much better sensor tech on the 5D4, am I likely to be getting better images with a 7D (mark I) + CLS filter + UV/IR filter removal?

sploo wrote in post #18575086
Modern Full Frame or old APS-C Modified


I've just started doing a bit of astrophotography (with a Skywatcher Star Adventurer tracking mount, DSLR and lens, no telescope yet).

I've got a 5D4, which is obviously great for wide field of view shots, but in the main I want reach. I have an old 7D (mark I) and I'm wondering if that would make a better choice?


So... despite the much better sensor tech on the 5D4, am I likely to be getting better images with a 7D (mark I) + CLS filter + UV/IR filter removal?

I do both, I have a 5D3 and a 6D FF --- these days the 6D gets more use than the 5D3 for astro work, mainly cuz of it's lesser weight

BUT I bought a 700D ASP-C and modified it myself. Tho I didn't ass any other sort of astro filter, ( maybe one day) it makes a huge difference to the red response
of the camera.
One top feature with the 700D is the swivel LCD screen, no more sore necks when trying to focus objects etc


The 7D cameras are a respectable unit and if you don't mind modding it, go for it
Surely you are not considering modding the 5D4 ?


Dave

Davenn wrote in post #18577111
I do both, I have a 5D3 and a 6D FF --- these days the 6D gets more use than the 5D3 for astro work, mainly cuz of it's lesser weight

BUT I bought a 700D ASP-C and modified it myself. Tho I didn't ass any other sort of astro filter, ( maybe one day) it makes a huge difference to the red response
of the camera.
One top feature with the 700D is the swivel LCD screen, no more sore necks when trying to focus objects etc

The 7D cameras are a respectable unit and if you don't mind modding it, go for it
Surely you are not considering modding the 5D4 ?

Dave

Thanks for the info. Definitely not modding the 5D

I suppose I should pull my finger out and just try the unmodified 7D for an evening's shooting, and if it looks acceptable then an IR mod plus CLS filter would then surely make it better than the 5D4 for that application. I don't mind modding the 7D as I don't use it that much now.