All-electronic shutters

[Macrero]

Yep, you're right, Lou. For macro work, either with continuous lighting or flash it would have virtually zero impact. Fully electronic shutter is still a nice feature though. I don't plan to buy a new camera right now, but when my Sony goes to a better place I will very likely buy a camera with fully electronic shutter.

[hkv]

Just to improve my understanding. Why is flash so important to you guys? I use my setup for micro only I yet I have never seen the need for using flash. I can set the shutter speed to 1/4000 and still get decent noise control under continuous light. At least with a 100W light source. 1/4000 is more than enough to freeze most cilia for example. Perhaps it is more important in macro? Can't you just blast it with more continuous lights?

1/4000 sec... at what ISO setting? With a 40X, 60X or 100X objectives you can get 1/4000 sec with DIC?

Charles, sorry for the late response, but I decided to do some testing so that I am not being overly optimistic here. And perhaps I was... DIC is of course more of a challenge as it is very light hungry. 10X, 20X is normally no issue, but at 40 and above ISO starts to climb. It also depends on how hard you squeeze the DIC effect. You can select an almost dark background (close to Darkfield) but also select a more greyish light background and still produce a nice DIC image. As a stress test, I enclose two examples from 40X DIC and 60X DIC. Somewhat weak DIC effect. No cilia, but just to illustrate the ISO requirements at 1/4000s shutter speed. In these cases, the 40X requires ISO8000 to get a decent exposure. At 60X Water Immersion it climbs to 12800. Noise is definitely starting to be a problem, but produces usable results with some filtering. These are single images and not stacked. Adjusted in lightroom to show their full potential. I can post the raw files if wanted. I think flash in this case would be useful to get the ISO down. Another question of course is if 1/4000 is more than fast enough and 1/2500 perhaps is enough to freeze motion? I guess it depends on the subject. That would improve the situation of course. I will try to make a comparison with flash if I figure out a good way to mount it to the scope. Also, I will try my 200W light source, but it uses a liquid light guide which I fear steal a good portion of the effect resulting in less than 200W effective illumination.

[Charles Krebs]

hkv...
OK. This is in line with my experience with my older BHS and a 100W illumination (~ 1/30 second at ISO 100). The difference is that I don't have a camera that I would use at anywhere near ISO 8000 or 12800! There are only a couple cameras that can pull this off, and I don't have one of them!

With flash I can get effectively about 1/2000 second (much faster at lower mags) at ISO 100.

Macrero (and Lou)....
The point Lou makes is, for me, huge. I very often work with "wet mounts" on a microscope. I can get each frame sharp with EFSC, but a very significant issue for me is that is it very common that the slight "kick" caused by the mechanical shutter operations at the end of (and directly after) the exposure is made will cause enough vibration to "jiggle" a subject into a slightly different position. This will generally ruin the "stack". Also, this slight vibration can startle a living subject enough to cause it to move slightly (often something like legs or antennae). IMO a fully electronic shutter is very desirable, especially on a microscope,

[hkv]

Macrero (and Lou)....
The point Lou makes is, for me, huge. I very often work with "wet mounts" on a microscope. I can get each frame sharp with EFSC, but a very significant issue for me is that is it very common that the slight "kick" caused by the mechanical shutter operations at the end of (and directly after) the exposure is made will cause enough vibration to "jiggle" a subject into a slightly different position. This will generally ruin the "stack". Also, this slight vibration can startle a living subject enough to cause it to move slightly (often something like legs or antennae). IMO a fully electronic shutter is very desirable, especially on a microscope,

I totally agree. This is a huge issue. Especially with immersion objectives which can carry vibration through the immersion media. The Canon 6D was not terribly shaky, but caused enough vibration to cause a problem. I have a fixed mount and no bellows, so every little vibration was clearly visible in the eyepieces. Even when using EFCS. I used to ruin every second stack and have to abort in mid stack due to slight movement. That is why I was so excited about the launch of a camera with true fully electronic shutter. It is a true game changer in stacking work of wet mounts. Also at 24 megapixel it has perfect resolution for micro work. You don't need or even want higher resolution as the post processing just becomes a nightmare. 24 megapixel is on the low side for macro at low magnifications (or for pure landscape photography), but for microscope objectives, it has the ability to capture the full resolution that the objective is capable of resolving under visible light. Even the APOs at low magnification. At high magnification you need relatively few pixels. With my setup, a 100X SuperAPO can be fully resolved by the camera (projected through a 2.5X photo eyepiece) with less than 3 megapixels. I would expect the (soon to be expected) Sony A7 mk III (or whatever they will call it) will have the same type of electronic shutter as the A9. Most likely priced at half the cost, or less, than the A9. I think the A7RII or expected A7RIII have too high resolution for micro work. Of course, you can ditch the pixels in post, but then you loose dynamic range and ISO performance.

[Lou Jost]

Of course, you can ditch the pixels in post, but then you loose dynamic range and ISO performance.

You'd not normally just ditch them, you'd bin them, improving high-ISO performance.