Exorcising a Vibration Demon

[rnabholz]

I had an experience last night that I thought I would share in order that it might help someone out there avoid the situation and the accompanying frustration.

I was setting up to do some more shooting of diatoms using the AO One Ten, and the Canon 70D shooting through the Trinoc. Everything was in place, I had located an interesting subject. I have been experimenting with a green filter for control of chromatic aberration, so I had that in place. I adjusted the exposure, which in this case was 1/8th at ISO 800 through the 100x oil.

Checked focus, then using the computer control software utility for the camera, release the shutter by pressing the mouse button. The camera presented the image review on the camera's LCD and I notice an issue. The image is just not sharp. So I check the focus, taking more care than usual, and press the mouse button again - same blurry result.

So now I check the Electronic First Shutter Curtain setting to confirm that it is set and on - check
Check that I had tightened the set screw on the photo tube after putting it in place - check
Check that the scope is sitting securely, not inadvertently sitting unlevel or rocking - check
Do a test release of the shutter with a hand on the scope base to see if I feel unusual vibration, none - check

A couple more test exposures same unsharp result.

So then I begin to think about what else could be causing vibration in the system and finally it hits me - it IS me.

There I set with my elbows on the bench, belly pressed up against the edge, vibrating like a tuning fork - no wonder.

I pull myself back from and off of the bench, even taking the mouse off of the bench and setting it on an unconnected surface. Make another test exposure and Whaddaya Know? Sharp as a tack.

The combination of the slower shutter speed caused by the green filter, the high magiification of the 100x objective, the long moment arm of the camera suspended at the end of the long photo tube, and my sloppy attention to isolating myself from the system at the moment of exposure all came together to finally make me aware of the importance of careful technique when working toward the extremes of the systems capabilities.

It was a good reminder and lesson. Makes me wonder about just what performance I have missed up until now.

Hope this can save some of you some trouble.

[JimT]

I notice lots of vibrations as well and take a deep breath before I trigger the shutter. I like your idea better about putting the mouse on a different surface. Thanks.

JimT

[gekko]

I noticed that too when I first started with my current setup. I don't have to lean or touch the microscope table: just shifting my body weight from one leg to the other messes up the image, so I stay motionless when I trigger the shutter release on the camera.

[zzffnn]

Maybe mass- loading the table and scope, say with dumbbells or sandbags? I know Charles Krebs did that.

Sometimes I noticed similar kind of vibrations (on my camera screen) when my kids jumped on the floor nearby.

[rnabholz]

I notice lots of vibrations as well and take a deep breath before I trigger the shutter. I like your idea better about putting the mouse on a different surface. Thanks.

JimT

Thanks Jim.

Something like this might be handy too.

DBPOWER® USB2.0 Wireless Finger Handheld Mouse Mice Trackball Mouse for Laptop PC https://www.amazon.com/dp/B009ZM75GG/re ... ixbM4VB9S4

[rnabholz]

I noticed that too when I first started with my current setup. I don't have to lean or touch the microscope table: just shifting my body weight from one leg to the other messes up the image, so I stay motionless when I trigger the shutter release on the camera.

Glad to hear i'm not alone.

I think it can be managed pretty well by just going hands off the scope and bench a second or two before exposure.

Thanks

Rod

[rnabholz]

Maybe mass- loading the table and scope, say with dumbbells or sandbags? I know Charles Krebs did that.

Sometimes I noticed similar kind of vibrations (on my camera screen) when my kids jumped on the floor nearby.

Interesting approach. Sand bags would be cheap enough.

Thanks

[KurtM]

Oh Rod, I can't believe you fell for that ... and an old photographer/astrophotographer at that!

Being an aficionado of all things vintage, I live in an antique house too, which means no foundation - just sits on blocks. If you jump up and down in the living room you can hear the china rattling in the kitchen kinda deal. When I'm setting up to take an image I can clearly see all my movements on the screen, even shifting in my seat or rolling the chair around. My microscope bench is a heavily built table, and the computer has its own little table (a TV tray would work). Like Jim, when the time comes I hold extra still and hold my breath...

Thanks for the chuckle. I miss my home and toys, but if it doesn't stop raining in Houston, sometime, eventually, I may never go back.

[rnabholz]

I am in the basement on a concrete floor, on a stainless steel table loaded down with all kinds of stuff.....but the wiggles were still there.

It reminds me of one of my early endeavors in my very short lived astrophoto career. I was using a simple barndoor mount on a pretty stout tripod set up in some grass in a park. I had some astro buddies hanging out with me that night, and I happily shot away for a couple of hours.

Every shot during which a buddy came by to chat was ruined by the vibrations of their foot plants in the grass! I was dumbfounded.

So you would think I would know better....

[zzffnn]

Maybe put some pads onto feet of your steel stable?

[kinase]

All the microscopes I use are on air tables and really heavy and I still step refrain from moving or touching anything when I take photos. If you don't have one, you should definitely get a cable release for the camera. Also always use mirror lockup.

[rnabholz]

Maybe put some pads onto feet of your steel stable?

That is an astronomer's trick, placed under tripod feet it can reduce the time it takes a scope to settle.

But of course it still vibrates - especially when the astronomer touches it.....

[rnabholz]

All the microscopes I use are on air tables and really heavy and I still step refrain from moving or touching anything when I take photos. If you don't have one, you should definitely get a cable release for the camera. Also always use mirror lockup.

Thanks Kinase.

I release the shutter with a mouse through the computer control software. A 21st century cable release. ;^)

The repeating lession in all the stories is to hold very still or don't touch it at all. And that is the easiest protocol to implement.

Thanks

Rod

[Interference]

The technique I use, but need to improve, (I mostly use flash now...) is the one of a lump of granite (ex kitchen worktop) under the scope to increase the mass, and Sorbothane(TM) feet under that. They're a squishy sort of rubber which absorbs vibrations remarkably well. It's not "bouncy" rubber. If you go to their site you can see what type, and importantly size, you need for the mass you're supporting. More mass is good, because it increases the "time constant" or reduces the "Natural Frequency", which leads to better isolation from ground-borne vibrations. There's an eBay seller or two who do good deals.

*I remember reading that Charles Krebs ( worth paying attention to! ) found that he had to physically not connect his camera to his microscope, so it's supported on a separate stand. Reason being, that any vibration at the camera causes less trouble that way.
Even using mirror-up, and Electronic First Shutter Curtain, most Canons produce a tiny "tick" noise which can be enough to move things - amazingly.
Shutterless cameras are an advantage of course!
I tend to play with LWD objectives ( to just about 100x) and incident light, so poked the flash head very near the subject, then found that the flash is also enough to move the subject unless it's nailed to the slide. Not good if you're stacking

* Oops I just read the rest of the exorcism thread

[KurtM]

I remember reading that Charles Krebs ( who's worth paying attention to ) found that he had to physically not connect his camera to his microscope, so it's supported on a separate stand.

There are lots of advanced techniques that require advanced ambitions ($$$ & complexity), and a separate mounting for the camera might be one of them. But I agree Mr. Krebs is well worth paying attention to for sure!

[Interference]

Sounds simple, doesn't it - "just use a tripod". I tried a Nikon copy stand which is hopeless .

The "poor man's Sorbothane" is apprently a mostlly-deflated inner tube, from something like a wheelbarrow tire. I haven't tried that one!

Sorry if this has been posted al;ready... Something else I think Charlie K was early to suggest, was to place a shallow dish of water on the back (ie topmost) on the camera. A Petri-dish or the cat's saucer, works.
Then fire the shutter and see if you can see any disturbance on the water.
I understand that with a 70D you should see "almost" nothing. Iirc the 50D was "really nothing".. I tried a 7DII, which was another "nearly" nothing. More nearly than a 60D, by a long way.
.

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

[kinase]

Not that you'll find this on any of the equipment for home use, but last high end Leica I used had reaction wheels on the parts that moved the stage to soak up movement from the stage moving around. Haven't noticed if they're on the confocal I use. The Leica ones were bright yellow, maybe they're just black on the confocal.

I mean, unless someone has enough time/skill to make their own reaction wheel system...

[Oktagon]

I notice vibrations at high magnifications if I don't use mirror lockup. My photo setup, which is Canon DSLR connected to Universal through upper port is quite steady. Enough so that I do not need to use air table (I have one). I did attach furniture felt feet to the base of the Universal, mainly so I can slide it around the table, but they also create additional layer of padding.
Zeiss used to make a special stand for WL which would allow mounting f the camera without physically connecting it to the scope.

[gekko]

There are lots of advanced techniques that require advanced ambitions ($$$ & complexity), and a separate mounting for the camera might be one of them. But I agree Mr. Krebs is well worth paying attention to for sure!

Depending on how one implements it, and what is available, I think mounting the camera separately need not be difficult nor expensive (much less expensive, e.g., than buying a new camera), although it may not turn out to look elegant (in my case it looks decidedly jury-rigged: I happen to have a bookshelf, right behind and next to the microscope, to which I attached the camera using inexpensive clamps and the like).

[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?

[zzffnn]

....so poked the flash head very near the subject, then found that the flash is also enough to move the subject unless it's nailed to the slide.......

^ Are you sure about that? Flash has no moving parts, doesn't it? Screwed-down wireless flash should not introduce any vibration?

[KurtM]

Gekko makes a good point - I have a picture of a homemade wooden camera stand that fills the bill, and doesn't look too difficult to make (for a guy like Rod, anyway, who's made his own astronomy accessories). The pic is on my home computer, though, so can't post it now.

[Oktagon]

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?

Yes, I can look at the part number on the base.

[gekko]

Gekko makes a good point - I have a picture of a homemade wooden camera stand that fills the bill, and doesn't look too difficult to make (for a guy like Rod, anyway, who's made his own astronomy accessories). The pic is on my home computer, though, so can't post it now.

Exactly right. And having seen the superb wood work that both you and Rod have done, it would be and look as professionally constructed and solid as anything out there (quite a contrast from my jury-rigged construction!)
Having said that, Rod's camera has the electronic first shutter curtain, so vibration from the camera should not be of concern. As I understand it, the vibration experienced by Rod was caused by touching the microscope or its table or movement of the floor. A vibration isolation table should solve the problem, but it is very heavy and very expensive, so the solution that Rod adopted, taking some care not to nudge the microscope table while taking a picture may be just as good, I think.

[rnabholz]

Gekko makes a good point - I have a picture of a homemade wooden camera stand that fills the bill, and doesn't look too difficult to make (for a guy like Rod, anyway, who's made his own astronomy accessories). The pic is on my home computer, though, so can't post it now.

Exactly right. And having seen the superb wood work that both you and Rod have done, it would be and look as professionally constructed and solid as anything out there (quite a contrast from my jury-rigged construction!)
Having said that, Rod's camera has the electronic first shutter curtain, so vibration from the camera should not be of concern. As I understand it, the vibration experienced by Rod was caused by touching the microscope or its table or movement of the floor. A vibration isolation table should solve the problem, but it is very heavy and very expensive, so the solution that Rod adopted, taking some care not to nudge the microscope table while taking a picture may be just as good, I think.

Thanks for the kind words about my woodworking skills.

You are spot on regarding my particular situation, it is pretty readily solved by simply not touching the bench during the exposure. Easy enough.

However the thread has spawned some interesting information, and I hope you all will continue the conversation about your setups.

Thanks

Rod

[Interference]

....so poked the flash head very near the subject, then found that the flash is also enough to move the subject unless it's nailed to the slide.......

^ Are you sure about that? Flash has no moving parts, doesn't it? Screwed-down wireless flash should not introduce any vibration?

Yes, dead sure!
Put a flash head up to sensitive skin and fire it, and you feel it.
I believe it's the rapid expansion of heated air.
You can see fly wings, fibres etc move and if you put a flash head against black paper, it chars it.
There must be some high speed video of it somewhere, but I can't find any. The timings would be interesting.
How much you need to separate the flash head from the subject so it doesn't happen, I haven't determined.


Further to Rod's interest in "spawnings", try a smartphone with a "Physics" app, resting on things. In most-sensitive X-Y-Z acceleration monitoring, you can pick up a lot.

[Crater Eddie]

I remember watching a PBS special on Harold "Pop Flash" Edgerton when I was a kid back in the 70's, he set a sheet of newspaper on fire just by holding it close to a large flashtube.
Neat stuff.
CE

[Oktagon]

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

[Interference]

I remember watching a PBS special on Harold "Pop Flash" Edgerton when I was a kid back in the 70's, he set a sheet of newspaper on fire just by holding it close to a large flashtube.
Neat stuff.
CE

What was the Guide Number for that?

[rnabholz]

I remember watching a PBS special on Harold "Pop Flash" Edgerton when I was a kid back in the 70's, he set a sheet of newspaper on fire just by holding it close to a large flashtube.
Neat stuff.
CE

What was the Guide Number for that?

666