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The great tripod & head thread!

MGrayson

Subscriber and Workshop Member
Not to encourage you (and so far you have been doing this without any encouragement from anyone here ;) ), but how does mounting the camera based on its center of gravity effect vibration? Would having the mass off center act as a dampener or a tuning fork?
Will,

I don't know, although I suspect balanced is best.

And speaking of unsolicited experiments ... everything in the last post was focal plane shutter (the leaf will only work with THIS lens and no teleconverter) BUT, I had to see how much it improved things. First, the raw data:



As before, huge shock when the human presses the shutter button. Two seconds later, an interesting set of clicks. I suspect that it starts with the aperture blades and is then followed by the leaf shutter. I'm going to stick with my (unjustified?) rule that the exposure starts at the last vibration peak. In that event, the vibration induced blur from a leaf shutter exposure is FAR below any of the focal plane examples:



I removed the bit of raw displacement data as it only applied to one curve, and the plot was getting too busy.

The top gray line is the head with no support and a focal plane shutter. Adding the bar *with or without the head* makes a large improvement. Adding a leaf shutter makes *another* and much larger improvement. Look at the 0.005 vibration level. The leaf curve passes that at about 1/45 second. The bar supported focal plane curves cross it at around 1/5 second, and the Acratech by itself at 1/2 second. The leaf shutter added 3 stops. The bar added 1.5 stops.

The moral? With long lenses, use a support bar and leaf shutter when you can. This is a rare (but no doubt temporary) setback for Dante.

Matt
 
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Shashin

Well-known member
Matt, this is all very interesting. (Just a flow of random thoughts.)

I am sure, in terms of tripod stability, a balanced load is important. This is particularly important if you are adjusting the position of a camera on a ball head--it is a pain when the load is off center.

What always bothers me is when I have some kind of rail, it also acts as a lever. If my Pentax 645D, similar in many ways as the Leica S, is just mounted directly on a head with the lens out in space, it seems more stable, both in terms of the shutter release, but also exposure. When the camera is on a rail, it is easier to position, but the rail acts like a lever, making the whole thing easier to flex on the tripod. In terms of mass, having a rail or not does not really change much. But having the shutter/mirror displaced from the point of attachment on the head does seem to change the stability when the force is at one side of the system--in this case the mirror box and shutter. If the vibration is in the camera, it would seem mounting it directly on the head would be the most rigid with the least leverage and the inertia of the lens hanging out in space would act like a stabilizer rod on a compound (you just knew I was going to get archery into this discussion ;) ).

I know the balanced load idea seem intuitively right, but the forces in the camera system are not at the center of gravity/balance point of the system. Where are the forces and where is the inertia?

Of course, that image blur might help with the moire...
 

jng

Well-known member
The moral? With long lenses, use a support bar and leaf shutter when you can. This is a rare (but no doubt temporary) setback for Dante.

Matt
Matt,

You’re hardly off the hook. Dante would like to see the data using electronic shutter… :love:

John
 

MGrayson

Subscriber and Workshop Member
Will,

The rail is for vibration absorption. It doesn't change the weight distribution of the camera/lens. You can still mount the whole mess wherever you want fore/aft.


Matt,

You’re hardly off the hook. Dante would like to see the data using electronic shutter… :love:

John
John,

To explain Dante's difficulty, the Leica S doesn't have an electronic shutter. It has live view, but then shifts back to focal plane or leaf when the shot is taken. I tried and lost interest in the Hasselblad X1D and Fuji GFX 100, so that leaves the larger Hasselblad H and Phase One. The costs of *that* shift dwarfs the Superachromats, so it's something of a double wall for our intrepid GAS enabler.

Oh, and something I hadn't realized until last night. Vibration depends on your f-stop as well. The timing between the aperture blades closing and the shutter (focal plane or leaf) firing is different depending on how far the aperture blades have to travel. This appears (and I may ACTUALLY stop investigating it) to affect the peak system displacement. Which may, again, just mean that one should avoid the dangerous shutter speed regime. Mind you, the blur isn't visible as blur - it just leads to a lack of Moiré. We used to call this an AA filter and do a bit of sharpening to fix it.

Matt
 

SylB

Well-known member
Matt, my experience in use with HC300 + H6 to get satisfyingly sharp pictures :
- tripod (3 series or 5 series Gitzo + Arca D4 head) always. Handheld is unreliable for me.
- using the lens foot on the tripod, as it balances quite well with the body's weight
- 3s timer, ridiculously easy to activate on Hasselblad H cameras
- of course, always leaf shutter on H system !

Interesting to read your experimentations and measurements...
 

P. Chong

Well-known member
thanks Matt for the detailed tests…yes, I read most, ok scanned through most is perhaps more honest. I know it’s not something you can attempt with your Leica 007, but with a less than solid tripod/head, might the IBIS (realise its GFX 100, 100S and 50 S II only) be of use?
 
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MGrayson

Subscriber and Workshop Member
thanks Matt for the detailed tests…yes, I read most, ok scanned through most is perhaps more honest. I know it’s not something you can attempt with your Leica 007, but with A less than solid tripod/head, might the IBIS (realise its GFX 100, 100S and 50 S II only) be of use?
The IBIS on the GFX100 is superb. The 100-200 zoom and the 250 prime can be hand-held in astonishingly low light. I think they are intelligent enough to work on a tripod without making the image worse, but I never tried it. Only after moving back to the comparatively primitive Leica S did I start thinking seriously about tripods again.
Best,
Matt
 

baudolino

Member
I *thought* I tried the leaf shutter when I first got the HC 300, and thought it didn't work with the S. Now, of course, it works just fine and the improvement is large. Thank you!
Matt
Interesting. I never believed this would help, as the focal plane shutter has to open anyway, just prior to the leaf shutter being released. Which I thought would result in comparable amount of vibration. But if it helped you achieve a sharper result, then that's good news and something to keep in mind.
 

MGrayson

Subscriber and Workshop Member
Interesting. I never believed this would help, as the focal plane shutter has to open anyway, just prior to the leaf shutter being released. Which I thought would result in comparable amount of vibration. But if it helped you achieve a sharper result, then that's good news and something to keep in mind.
I thought about that. Putting a microphone on the assembly (I'll spare you all. No I won't.) showed the order and timing of the focal plane shutter, the aperture blades, and the leaf shutter. Now this is sound, not camera vibration, but it helps us with timing. Here is a 1/24 second leaf shutter exposure:



The sample begins after the 2 seconds of silence following my shutter press. The large time division are 1/20 second. The small ones are the same 1/100 second resolution as my accelerometer, so we *are* seeing further into the atom. I chose this example so there would be no ambiguity about where the exposure was. The 1/15 second one is confusing. The first three shocks are the leaf shutter closing, the aperture blades closing, and the focal plane shutter opening in some order - I can't tell which, but that all has to happen before the actual exposure. As you can see, the system has time to settle down (almost 1/10 second) before the exposure starts with the leaf shutter opening. The exposure is marked by the vertical black lines. Then the system resets in a series of further clunks. Afterwards, not shown in this sample, the mirror resets.

Of course, I could be wrong about the aperture blades. They could be closing in that disturbance marking the leaf shutter opening. But the focal plane shutter is definitely given time to calm down before the leaf goes into action and, of course, the leaf shutter has to close before the focal plane shutter opens!

Matt

Amusing side note: I shot a Siemens star using my laptop as a distant target (so that pixels wouldn't matter). After comparing the results, I noticed that the text from Lightroom, open in the background and visible off to the side, was a much better and easier to read indicator of sharpness. Results, the same as every other analysis. At 1/4 to 1/30 second, the leaf is slightly better than the focal plane, with the exception of the 1/15 focal plane, which is a good bit worse than any of the others. Not terrible, mind you, just worse.
 
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MGrayson

Subscriber and Workshop Member


Sigh. I made high-speed (slow motion) videos to go with that waveform. And I WILL spare you those. Slowed down 50 times, it sounds like the hold of the Nostromo, full of spooky echoes. Noises A and B remain unidentified. But the leaf snaps shut at C. Then the aperture blades simply crawl. That entire 1/10 second from C to D is the aperture closing down to f/11. I can't tell exactly when the focal plane shutter opens, because there is a closed leaf shutter in the way! The leaf snaps open at E - it's faster than my frame rate, which it better be if you're able to shoot 1/800 second with it. At F, the end of the exposure, the leaf snaps closed. What's amazing is that the leaf snaps open again at H, making that last big noise. So at F or H, or possibly G, the focal plane shutter must have closed. After that, the aperture blades crawl open for the rest of that time slice, and the mirror comes down.

I suspect I've gone OT here. If I do more shutter analysis, it will be in a different thread.

Matt
 
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dchew

Well-known member
Hey Matt,
Egged on my @jng 's comment, I did a similar test with my tech camera/electronic shutter/aperture mount Rodenstock lens fired remotely from my iPhone:

aperturemount.jpg

:ROFLMAO:

Seriously, I personally think the work you've done is interesting and relevant to the topic. The relative impact of leaf vs FP vs secondary lens support is one example.

Dave
 

MGrayson

Subscriber and Workshop Member
Hey Matt,
Egged on my @jng 's comment, I did a similar test with my tech camera/electronic shutter/aperture mount Rodenstock lens fired remotely from my iPhone:

View attachment 188590

:ROFLMAO:

Seriously, I personally think the work you've done is interesting and relevant to the topic. The relative impact of leaf vs FP vs secondary lens support is one example.

Dave
Dave,

I'm going to respond seriously to what was no doubt meant as a humorous poke in the ribs. I LOVED using tech cams on photo workshops. I bought my own ... and never used it. It just didn't fit my shooting style at home. The Leica S did. I loved using it for walking around - seeking interesting light, geometry, and city life. I didn't use a tripod, didn't use anything longer than a 120, and used no ND filters for long exposure effects. Then I started using the S180 - the longest lens in the S system. It was difficult to focus, and magnified live view was jumpy, so it started whispering "tripod" at me. Well, I went monopod first, and started taking those high elevation pictures. I'm not doing those right now as I have a borrowed camera, and returning it after an 8 foot fall would be difficult to explain. But then I saw what could be done with a long lens with a tripod and, furthermore, that there was a lens perfectly adaptable to the S system (I tried the Contax 350/4, but it is huge and not very sharp, so returned it). Enter the HC 300. So I'm trying to see what I can do with it and what its strengths and weaknesses are. I will not be walking around with it hand held looking for random interesting photo ops!

Would I love a Phase XT system? You bet. @jng 's rig? Absolutely! Would I use it them as much as the S? Probably not.

Best,

Matt
 
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MGrayson

Subscriber and Workshop Member
You knew I wasn't done. I recorded Focal Plane shutter exposures. There are always two noises before and two after the actual shutter moving. The shutter itself takes a bit less than 1/100 second to open or close - that's the flash synch speed. So those other noises aren't the shutter moving, but are some other part of the mechanism. That leads me to believe that A, B, and C are the FP shutter preparing to open, and it finishes immediately after the leaf shutter closes at C. Similarly, it closes at F, the end of the exposure, and makes noises at G and H, which is when the leaf shutter opens again.
M
 
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Shashin

Well-known member
Now, combine the sound and vibration data and see how they correlate! (Remember, you opened this can of worms.)
 

MGrayson

Subscriber and Workshop Member
Now, combine the sound and vibration data and see how they correlate! (Remember, you opened this can of worms.)
A good suggestion, Will. And I can't resist a an opportunity to lecture (but you knew that....). So...

Here's the sound from a one-second leaf shutter exposure superimposed on the vibration data from a shot with the same parameters. The sound of the mirror lowering is off the end of the vibrations chart, but we really don't care about vibration by then.



This lets us peer inside the "room where it happens", and it explains the width of the leaf shutter disturbance, ᕕ( ᐛ )ᕗ. Right before t = 1 second, the giant vibration peak of finger push and mirror up. Two seconds later, the three bumps visible in rapid succession: t = 2.85, Leaf shutter closing and FP shutter opening, t = 2.95, aperture blades reaching f/11, and t = 3, the Leaf shutter opening. This tiny bit of complexity comprises letters A through E in the sound plot above! You can barely make out A and B leading up to the big noise C. Then we have one second of silence during the actual exposure. At t = 4, the Leaf shutter closes, FP closes, and, 1/10 second later, the Leaf opens. From t = 4.1 seconds on, we have aperture blades recovering and, at t = 4.25, the mirror lowering. F, G, and H lie between t = 4 and t = 4.1! The difference between this sound plot and the previous one is that, instead of being a 1/24 second exposure, this one is a full second.

I'm guessing that the bigger vibration peak at t = 4.1 is from the FP shutting and the Leaf closing and opening in a much shorter interval than at t = 2.8, where there was deliberate time for the system to settle down before the exposure.

Matt
 
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MGrayson

Subscriber and Workshop Member
Wait, Will. I'm not done!
This is a zoom into that t = 2.8 to t = 3 region where the exposure starts. I could then overlay the annotated sound file.... and yes, I matched the time scales. :cool:



Matt
 
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MGrayson

Subscriber and Workshop Member
Hi! Me again. Just some more observations with some other long lenses. While the HC 300/4.5 is a more modern lens and has a usable leaf shutter on the S, it's a dead end. No extension tube or teleconverter will work with it and the S and, having no manual aperture setting, it suddenly becomes harder to use than a perfectly manual lens. Enter the older Hasselblad V lenses. There is an S adapter with no electrical or moving mechanical connections. So what do our elder brethren provide? The 250/5.6 and 350/5.6 Superachromats and the APO teleconverter 1.4XE. With Dante as my Virgil (think about that...), I got my hands on both of those lenses and have had a few weeks with the 250 and a few days with the 350, and I can report a few things.

First, they are not the highest contrast kids on the block. Zeiss says that they don't provide the T* coatings as that would block some of the IR which the highly corrected CA would render in focus. The acuity (if I'm using that word correctly) suffers. Yet the detail present is lovely and takes sharpening VERY well, if that's what you want. I like the brick and stone in buildings to look the tiniest bit velvety - as if they would be soft to the touch.

But this is a tripod and head thread, so enough about the optics! The 250/5.6 SA is a much smaller and lighter lens than the 300/4.5 or 350/5.6. It's about 2 lbs. and the bigger ones are both 4 lbs. Not surprisingly, the 1/8-1/15 second issues don't show up with the 250 and DO show up with the 350. Using a lens support rail greatly ameliorates this - better than it did on the HC 300/4.5 - but it's there, and a ND filter set is handy to get you out of that range into the >1 second world, where there is no apparent vibration.

Matt
 
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jng

Well-known member
Hi! Me again. Just some more observations with some other long lenses. While the HC 300/4.5 is a more modern lens and has a usable leaf shutter on the S, it's a dead end. No extension tube or teleconverter will work with it and the S and, having no manual aperture setting, it suddenly becomes harder to use than a perfectly manual lens. Enter the older Hasselblad V lenses. There is an S adapter with no electrical or moving mechanical connections. So what do our elder brethren provide? The 250/5.6 and 350/5.6 Superachromats and the APO teleconverter 1.4XE. With Dante as my Virgil (think about that...), I got my hands on both of those lenses and have had a few weeks with the 250 and a few days with the 350, and I can report a few things.

First, they are not the highest contrast kids on the block. Zeiss says that they don't provide the T* coatings as that would block some of the IR which the highly corrected CA would render in focus. The acuity (if I'm using that word correctly) suffers. Yet the detail present is lovely and takes sharpening VERY well, if that's what you want. I like the brick and stone in buildings to look the tiniest bit velvety - as if they would be soft to the touch.

But this is a tripod and head thread, so enough about the optics! The 250/5.6 SA is a much smaller and lighter lens than the 300/4.5 or 350/5.6. It's about 2 lbs. and the bigger ones are both 4 lbs. Not surprisingly, the 1/8-1/15 second issues don't show up with the 250 and DO show up with the 350. Using a lens support rail greatly ameliorates this - better than it did on the HC 300/4.5 - but it's there, and a ND filter set is handy to get you out of that range into the >1 second world, where there is no apparent vibration.

Matt
Matt,

Surely you have a photo or two of the contraption to share!

John
 

sog1927

Member
There is an S adapter with no electrical or moving mechanical connections. So what do our elder brethren provide? The 250/5.6 and 350/5.6 Superachromats and the APO teleconverter 1.4XE. With Dante as my Virgil (think about that...), I got my hands on both of those lenses and have had a few weeks with the 250 and a few days with the 350, and I can report a few things.



Matt
What, no 500mm ApoTessar?????????
 
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