[gregbradley]

Choice of gear and how it is setup is heavily influenced by the type of target you intend imaging. 12 inch F8 is really a long focal length instrument ideal for galaxies with a modest chip size (STL11 would be close to ideal there). It would not be suitable for imaging the dust areas Jase recently imaged though as the FOV will be too narrow. But targets for the 12 inch RC would be the large number of galaxies that seem to all be near NGC253. There are quite a few around it for some reason.

Fast F ratio with large aperture and large chips though is the direction this pursuit is generally taking. It tends to reveal hidden dust, detail in commonly imaged targets etc. A reducer may work with this new RC, yet to be determined. It would be tough. I was not able to use one successfully with an STL on an RCOS 12.5 inch. The AP reducer was more for small chips like the ST10.

The lastest larger chips from Kodak in the really large sizes like 31megapixels and up are either one shot colour (KAF 31600, KAF40000)
with peak QE around 43% or low QE (mono versions of KAF39000 30% and KAF50100 25% which is really pretty low). STL11 is around 51% and 31% the for Ha band. The 16803 is peak 60-61% and about 58% in the Ha band. KAF3200 (peak QE around 89%) is very high in the Ha band so is the KAF6303 (65% at Ha band).

So to reveal new dust/Ha structures would require a large aperture, fast F ratio and longer total exposure to capture it with these larger chips. Or you get a back thinned very expensive chip with 93% QE or you get a compromise - the largest FOV chip, with the best QE, the largest dynamic range, lowest noise and biggest well depth (so long exposures don't overexpose stars, bright objects). It seems to be a compromise very often. Some chips seem to have a lot of these factors aligned and these are the ones that become popular - KAF8300 ( QE 56-60% full well 25,500 small pixels - good for fast systems, short focal length) 11002 chip (QE 51% full well 60,000 a good compromise that suits most scopes and does not suffer from ghosting) KAF16803 (60% QE, 100,000 full well 79db dynamic range - this is the best of the current chips).
KAF 09000 and KAF3200 suffer from RBI a lot (ghost imaging) requiring a fix in Apogee and FLI cameras that has a side effect of increased noise and really requires heavy cooling to minimise this trapped charge leakage during an exposure from the ghosting control.
Too bad. On paper the KAF 09000 would be the chip of choice.

The conclusion being that these newer really large chips (larger than 17 megapixels) are not really that suited to astrophotography.

The only factor the scope has to play here is larger aperture has a better chance of picking up smaller objects and faster f ratio or higher QE will ensure you can image it successfully without taking 2 weeks of often rare clear skies.

Even with your own home observatory there is a definite limit imposed by the weather about how much you can image a particular spot. This then tends to limit experimenting with new and untried.

I like to do better than what I did before but I also like to image new things.

A list of reasonable targets would be helpful. I am always looking for new and unusual targets. There have been a few here on this site in the last few months.

ic 2631 from the fellow in Chile (Leonardo?) I also imaged this one
Marco's Supernova remnant he imaged (I tried to image this one but its too low still)
NGC346 in the SMC I also imaged this one (yet to be released)
Jase's recent South Pole area nebulas

Many galaxies are very small and not very photogenic but there must be a decent list still of those that are not often imaged.
Can you make a list of what you think would be interesting targets? I would be interested.

Greg.