gcisko wrote: ↑Fri Aug 28, 2020 4:34 pm
JayTee wrote: ↑Thu Aug 27, 2020 9:33 pm
Wow, great image size and great resolution. I've gone as far as 5600mm for FL. I would need a 4X barlow to get close to your 13,650. Seeing your results, it may be worth a try.
Thanks for sharing this amazing image.
Cheers,
JT
This brings up an interesting point. At some point, the magnification will be too high. For visual it is something like 50x per inch
aperture I thought. Isn't this the same for imaging? I never have seen this addressed.
Isn't this an interesting question, is there such a thing as too much focal length for planetary imaging. Luc, who won today's TSSAPOD, used a focal length of 13,650mm or for us USA types that's almost
45 feet!!!. The most I've ever used is 5600mm (
FL = 2800mm with a 2X barlow). If I were to use a 4X barlow I could get that up to 11,200. But managing that much
FL and dealing with centering the object, the ROI (is it big enough), and the inherent, unavoidable "shakes" might make this much
FL very problematic.
I see this as both a physics question and a physical question. At what point does
FL supersede resolution and light grasp for a camera? And is your mount stable enough to handle that much (for want of a better term) magnification?
To start off with using visual ROTs (rules of thumb), regarding the human eyeball, just doesn't apply to imaging with a camera. Our eye is a rather small
aperture and slow video camera and has well documented limitations. But has anyone seen any limitations as to how far you can push
FL in an imaging system?
Please, let's discuss this. I'm eager to hear your thoughts.
Cheers,
JT
PS, This quote is from another forum (solar system astrophotography). I brought it over here because this tangential topic might "steal" the topic away from the OP.
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