Exorcising a Vibration Demon

[75RR]

Zeiss used to make a special stand for WL which would allow mounting f the camera without physically connecting it to the scope.

Do you have an image or catalogue number for that?

47-62-50

Thanks

[c-krebs]

I need to replace a Canon, and am watching the new 80D's prices creep downwards. I wonder if anyone has tested the shutter

Was reading through this thread since "vibration" has been a constant nemesis in microscope photography. I can offer some info to "Interference" in regards to his question about the Canon 80D. I did rent one primarily to check out the shutter vibration. Unfortunately it does exhibit a little "kick" when that little noise occurs just before the exposure starts (EFSC turned on). Canon had a good thing going with the EFSC on the 40D, 50D, most "Digital Rebels", and most of the FF cameras. But they have since screwed it up a little. I don't know what makes that little internal noise just prior to the start of the exposure (it's been mentioned that it is an electronic component, a "charge pump"... whatever that is ) but it definitely causes a little noticeable vibration (in some models... not all) when it occurs. (The 80D overall is a really nice camera!). It does not seem to be as severe as a non-EFSC shutter, but still enough to take the edge of an image if your set-up is not super rock solid. Unfortunately I don't know for sure what current Canon models have avoided this introduced pitfall. My old 50D is absolutely silent at the start of an exposure and there is not the slightest hint of vibration (until after the exposure when the second mechanical shutter curtain closes). But the sensor and imaging technology have improved is the past 8 years so it would be nice to update. My T3i makes the little pre-exposure "squeak" but seem to be OK in the vibration department. But EFSC is getting more common in the industry, and even fully electronic shutters are now available on a few interchangeable lens cameras. Having tried out one camera with a fully electronic shutter option I must say it is really nice! I would really like to have it on my next camera.

[KurtM]

I watched your series of videos, Charles ... and need to go through them again as it's an awful lot of information to soak up. Does the T3i have EFSC, and should I be using it?

(I just now Googled it, saw your page, but simply don't have time to comb through it just now so hope I may get away with just asking about the T3i specifically here & now. The explanation you gave on the video for how it works/what it does was clear. Thank you so much for your generous sharing of knowledge!!)

[c-krebs]

Kurt,

The T3i, as with the other digital Rebels, always uses EFSC when a continuous light exposure is made from live-view. There is no setting to turn it on or off. (Different story when using a Canon electronic flash). With the 50D and other"xxD" series Canons, as well as the FF models you need to select it and turn it "on" from a menu. The T3i is a nice microscope camera, especially with the articulated rear screen. Vibration prior to exposure does not seem to be an issue. The only reason I was recently looking to replace mine was because it died on me (after very heavy use) and I thought the repair would be more than it was. But it is back in service again.


One thing that does not get mentioned is the great desirability, when recording an image stack, for very low vibration even after the exposure. This is more obvious with "wet mounts" or live subjects line a nauplius that has paused it's activity. With good EFSC there will be no negative vibration effects in each individual frame. However, after the exposure the shutter (and in some cases the mirror as well) needs to recycle. This will cause some vibration, but will quickly dampen out before the next exposure. This is no problem with "hard" mounted slides, but in a wet-mount this re-cocking can cause a slight "jiggling" of the subject on the slide, causing it to move ever so slightly. This makes getting a clean z-stack more difficult or even impossible. So EFSC can be a huge benefit by itself, but a fully electronic shutter would be great for some subjects when acquiring a stack of images.

[KurtM]

Interesting - thanks again! I got my my T3i in September 2012 as my first dSLR after a good forty-plus years of photography as a hobby, and after accumulating a small mountain of Pentax and Olympus film SLR gear. The longer I own it, the better I like it; it just seems to do everything right, again and again. Lately I've been considering a second body, in large part as a backup to the T3i in case of accident or malfunction. The choice I see is a new T6i, or save a few bucks plus get an old favorite and buy a used T3i. Either way it is intended to serve both for photomicography and general all-around use.

Any comments to help decide would be greatly appreciated!

[c-krebs]

Kurt,

Personally I'm leery about the T6i (and T6s) after some reports and images about a potential problem with microscopy and astro-photography. See this thread. "pwnell" is a good photomicrographer and very particular, so I thought perhaps he was looking "too hard", and maybe altering contrast way too much in order to see this. But he sent me a couple of raw files and when I opened them without any severe contrast settings the lines were there. They appear to correspond with the phase-difference AF elements embedded in the sensor used for the "Hybrid CMOS AF III". They were not in all pictures, and were certainly not as severe as the "exaggerated" samples in that thread, but were undesirable nonetheless. I really doubt that they will ever appear in normal photography. I located and opened many T6s raw files from "conventional" photogrqaphy, and even knowing where to look, and tweaking contrast to an absurd degree I could see no trace of them.

You know how, with high magnification photomicrography (60X and 100X) the slightest speck of dust on a sensor shows up extremely clearly... I'm talking about spots that would never occur in "normal" photography. I suspect that this is what is occurring here due to the extremely small effective apertures encountered with high mag objectives.

[KurtM]

Oh I know who pwnell is alright. Thanks man, I think my question got answered.