70-200/2.8 I tripod ring flex

I was taking some night pictures on a tripod last night with the 70-200/2.8 (mk 1). I noticed that with a slight amount of gusty breeze, exposures longer than 1/50th of a sec were getting smeared... and I really needed to get up to about 2-3 seconds for the aperture I wanted (so even outside the range of IS compensation). It really seemed like there was a lot of play between the tripod ring and the lens, the lens and the body, and the ring's foot and the tripod's baseplate. I won't even get into how bad it got with an extender on.


Do I have a faulty tripod ring? Or is this standard behavior? I recognize I'm using this lens outside of its typical usage envelope like this. Is there any way to improve it? I had every knob on the tripod, baseplate, and tripod ring twisted as tight as I could. The tripod (manfrotto 055b) seemed to be stable compared to the multiple degrees of motion the camera was making.


I presume such flex is not nearly as bad in the 400/2.8-and-up super teles. Can anyone confirm?


Thanks.

Did you have IS on while you were shooting on the tripod? If the IS was hunting a little that may be why your images were smeared.

Some with IS, most without. The ones with it off looked better, but not by much.

Of course everyone's standard is different but you're using the word "smeared" so I guess it must be pretty noticeable. But are we talking pixel-peepin' "smeared" or do they look bad at normal viewing distances too?

In any case, when you mount the ring on the lens and tighten it down does it feel loose then? If it does I would take it back because that's not normal.

Mine (same lens, orig version), once you tighten it down it's solid, it becomes one unit. Same with all the connections, lens to ring, ring to lens plate, plate to QR, there's no play at all until I get to the QR-to-head connection - but that's because I'm using an inexpensive ball head. Even so, once I let things settle, unless it's really windy (and "things" don't ever settle) I get sharp results from that lens.

I assume something's wrong with your tripod ring or your lens (or both) - they're not mating up the way they should. At the very least, the lens and ring, once the ring is tight, should feel like one solid hunk of metal - no wobble, no play, no slippage.

btw, I don't think you're using the lens "outside its typical usage" if by that you mean you're expecting too much. I need anywhere from 1 sec - 30 secs. for pre-dawn shots and I get sharp results, certainly nothing like "smeared" images.

Let us know what happens...

Well, I could actually *see* the camera and lens wobbling in the breeze. If I can get this uploader figured out:


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That's a 2 sec exposure, 100% zoom, tiny crop. There's pretty obvious X & Y movement, and I'm pretty sure that shot was done with the tripod square and "settled" and even with the tip of the lens against a wooden column for a fourth point of stability.





Further investigation this afternoon in good light leads me to believe that the ring mates well with the lens but there might be a very little (almost negligible) bit of play between the lens and body (7D, so metal mount both sides), and most of what I was experiencing was probably between the ring and the tripod mounting plate or the tilt & pan head itself. I'm going to chalk this up for now to be an excuse to find a sturdier tripod head and several assistants with wind screens...

what part of the frame is that - is DOF or diffraction having any effect here?


Unless I could feel obvious play in any of the metal-metal connections I wouldn't worry too much about the lens/ring.


In any case you can't go wrong building a sturdier system!

f/9, about 1/3 from top edge, 1/3 from left edge... I'll settle on diffraction (and out of focus) for the halo, but all four points of light (1 big, three small) were quite stationary. The contrast from the background (black) made them good measures of the vibration. In some they look like hand-holding vibration by a caffeinated pigeon.

Were you shooting the sky?

Just like a chain is only as strong as its weakest link, a camera is only as stable as the most unstable part of its support. You've mentioned the Manfrotto 055B legs - a decent set. The lens mount to the camera is not a point of instability, nor is the tripod ring to lens coupling likely to be one. You mention a pan & tilt head - what brand and model, and what's its rated capacity? The 7D + 70-200mm f/2.8 is a reasonably heavy combo. Also, what (if any) quick-release system?

Head is an 804RC2, which claims to be rated for over 8.5 lbs. Lens+body combo comes out to (back of envelope) a little over 5 lbs.


Despite the near-omnipresent rants about the smoothness of the head's adjustments in Internet reviews, it would seem up to the task... although now I do recognize it's the most "economical" element of the setup and might be due for replacement.