Wanted to get some opinions on the above cameras. I’ve searched and read the CN posts on these two and still can’t decide. Scope is an FSQ130 at F5 or F3.5 with the .7 reducer. Mount is the EM 200 (unguided) which is slightly under mounted. Seeing is average and moderate LP. Targets will initially be the brighter and easier ones. My aim is not to worry about sensational results but to ease my way into AP with a camera that can also be used photographically, wild life and woodland shots.
810a pro’s :- higher pixel count and modified. Seemed a good match to the FSQ130 resolution.
810a con’s :- no articulated screen, live view isn’t great. A little worried about the normal picture taking with a possible red shift effecting all pictures? Larger files.
A7S pro’s :- superb live view, articulated screen, excellent sensitivity which should help with quick captures? It isn’t modified so should produce nicer normal photographs. Smaller files. Lighter than 810a.
A7S con’s :- star eater for anything over 30’s. Didn’t appear to be a good pixel size for the FSQ?
It isn’t and won’t be modified so wont help bring nebula details out as well as the 810a.
A7Sii pro’s :- IS for normal photography. Genuine 4K video recording. Slim chance star eater might get fixed over the original.
A7Sii con’s :- worse cooling due to IS. More expensive than A7S. Star eater kicks in after 4s.
So thats my current understanding. I’m drawn to the A7S original because I’m thinking it will be easy to grab quick data and repeat if required. The live view will be a pleasant experience almost emulating NV and EAA. I’m concerned about the Sony because the star eater algorithm appears to rediculous. The supporting software limited and the pixels don’t seem an ideal match for the FSQ.
I’m drawn to the 810a because the pixel size seems a good match and it’s modifications help with the AP. I’m concerned about the Nikon because the modifications can be seen in normal photography and the live view isn’t anything like the impressive Sony.
Can the Sony’s sensitivity and capability to quickly capture data help overcome its short comings?
Seems like you are familiar with the literature on the matters.
Let me point out a matter you didn't mention:
Silent shutter (Sony). Drops bitdepth from (13+1) to 12bit, but great for wildlife shooting were clicks could make some creatures jumpy. Great for timelapse for not wearing out camera shutter.
Reminder: the Sony a7s already has decent sensitivity for the h-a 656.3 red without any modification needed. In fact I get a higher red response with a 7nm h-alpha narrowband filter on an unmodded a7s (at highest ISOs for sample shots) compared to a modded Sony a5100 with the IR filter removed and same optics and narrowband h-a filter used with its highest ISO for sample shots, meaning the high ISO boost available in a7s more than compensates for the lower 656.3nm transmission on the unmodded a7s camera compared with a modded camera with lesser low light capability.....
Of course no mod=longer exposure that moves you closer to >30s and star eater, if the effects are noticeable to you for the particular targets in the first place..
Handicap of LP: if you are certain to limit yourself to locations that wont give you dark skies, you may be hindering benefits one or the other brings to the table.
As to "live view"," the point is you can ramp up to 409,600 while using 1/30 sec in movie mode to frame the shot being able to see quite faint stars.
You can go crazy there dropping to 1/4 second to give a boost if your skies aren't blown out (at ISO 409,600) but works in dark skies, just the 1/4 sec has motion blur....
Using live view, especially if you have a display (either a portable 7") or larger attached with HDMI you can easily frame the shot and focus (also with the focus magnifier setting)....
After getting things set, you then drop down to a reasonable ISO and set your longer exposure and take shots....
As to the particular benefits and problems, the key dilemma is appointing an accurate "weight" to what they contribute/detract to the situation.
I will say that if you owned a 810a and switched to an a7s, you would immediately appreciate the advantage of the feedback of the high ISO potential and from my experience it has helped me learn quickly the nuances of data acquisition and has allowed me to spend less time aligning, finding alignment stars, starring at a computer screen to focus or to see whether a faint image has the correct information in it,
and more time just taking pictures, glancing at what samples look like, and then taking more shots.....
I'd love to see a group experiment with new photographers, some given the 810a and others given a Sony a7s version.
Give them a period of months to shoot under dark skies and learn how to improve their shots.
Then compare the images, especially if there could be a neutral "image processor" individual that would stack the different samples, so the comparison stayed with the use of the cameras and not developed skills on how to stack and process images....
Imagine such being tested^ How different would the images appear (given a range of targets)? Would they even be noticeable? Did the camera features allow certain individuals to learn and get images more efficiently? Are there ceilings on the benefits the different cameras provide? Are there minimums needed externally to best enhance what the features bring to the table?
Again the more balanced and properly weighted the pros/cons, the more accurate your conclusions on what will help.
However, I can't really say the literature correctly demonstrates an accurately weighted value to the benefits/cons of the different features....
There are enough on CN and astrobin to give a nice sample of images (done right) that can be done by your different candidates...
Not to mention individual differences in requirements pertaining to styles of workflow, convenience of process, etc. etc.....
It is best to see the features/cons as having starts and ends/minimums/ceilings depending on context and not as all or none qualities..
For example: Sony live view: best at f/2.8 and under, helpful at f/6.3 and under, worthless about f/8...
ISO 409,600: not even useful in high light pollution where a live image can reveal blown out skies with fast optics.......
Noticeable difference in spatial resolution give pixel size v optics: depends on the target, what you do with the image (4K display? print? just browse on phone, etc).....
h/a sensitivity useless on glob clusters, etc..