Electronic shutter on the Sony A7R II

Started 4 months ago | Discussions thread
Alen K
Alen K Senior Member • Posts: 1,272
Re: Electronic shutter on the Sony A7R II

For deep-sky astrophotography, mechanical shutter life is not much of a problem because most people mount the camera or telescope/camera combination on some sort of tracking platform, be it a portable tracker or a full-blown equatorial mount. Exposures in that case are typically at least 30 seconds to several minutes long. Only tens to hundreds of sub-exposures are then required for typical total exposure times.

Shutter life could potentially be a problem if attempting to do long total exposures with an untracked camera, since sub-exposures would necessarily be much shorter, perhaps only a couple of seconds. If you try this, you will soon tire of it and buy a tracker.

Planetary and lunar close-up astrophotography, on the other hand, is best done with thousands of short (1/30 second or shorter) exposures in order to get enough candidates that are either wholly or partly minimally effected by atmospheric turbulence. (I am oversimplifying.) Special stacking software is then used to automatically sort through the frames to find the best ones and then aligning and combining them.

Practically speaking, that means taking video, not individual exposures. Furthermore, the video should preferally be uncompressed, something that most of today's DSLRs and mirrorless cameras can't do without extra secondary equipment. It is far more practical (and less expensive) to use a dedicated planetary camera feeding video over USB to a computer.

Note that planetary and lunar close-up astrophotography requires a lot of image scale, at least if you want to capture any actual detail. In practise, that means attaching the camera to a telescope, the larger the better. Telephoto lenses just won't cut it, so any concerns about the design of such lenses (autofocus, etc) in that context is misplaced. You wouldn't be using them for that purpose in any case.

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