First review I've seen for the Tamron SP 70-200mm f2.8 Di VC USD in Nikon mount

[Cage]

A most comprehensive and thoughtful discourse Andrew.

Now my enlightenment of the laws of Physics dates back to the 1950's and may be a little rusty, more likely very rusty, but would not the fulcrum point in the camera/lens equation be the lens mounting point.

Irrespective of where the tripod collar sits on the lens, you still have the total unsupported weigh of the camera body hanging off the mounting plate. I always assumed the balancing point was more to do with exactly that, balance, so you were not placing a front or back heavy set-up over a tripod head.

From a stress point of view, as I said above, it seems the better option to have 850gm unsupported, than the 1.3kg that my D600 + grip weighs. (I just weighed them)

What is the unknown here is how that combination will balance on my tripod, and whether it causes any unwanted additional vibration.

PS: The whole purpose of this exercise is to get a VR lens that's not too heavy, to use when hand-holding is required.

PPS: This is starting to make my head hurt.

[Rattus79]

I'm another happy Sigma 70-200 2.8 owner, although, mine's the older non os version since I'm a pentax shooter, it's just not necessary.

It is a little soft at 200, but from everything I read comparing it to the tammy, the tammy was supposed to be sharper, but slower to focus as it was a screw drive focus system. I'm not sure if they have an SDM (or whatever your proprietary brand calls it) version yet though.

[Cage]

I'm another happy Sigma 70-200 2.8 owner, although, mine's the older non os version since I'm a pentax shooter, it's just not necessary.

It is a little soft at 200, but from everything I read comparing it to the tammy, the tammy was supposed to be sharper, but slower to focus as it was a screw drive focus system. I'm not sure if they have an SDM (or whatever your proprietary brand calls it) version yet though.

I had the same model with my now departed K5 and loved it.

[MrQ]

Irrespective of where the tripod collar sits on the lens, you still have the total unsupported weigh of the camera body hanging off the mounting plate. I always assumed the balancing point was more to do with exactly that, balance, so you were not placing a front or back heavy set-up over a tripod head.

+1 ... in fact, if you're looking at the foot as the fulcrum then you actually have the weight of half the lens balancing against the other half + the camera. Not a great situation for minimising vibration. And the entire camera weight is still hanging off the mount putting stress on the lens mount.

I have a feeling this is one of those "UV filter for lens protection" arguments. If you WANT a foot for a particular lens then by all means get one - they're a great idea for large, heavy lenses. It doesn't change the fact that it's not NEEDED for this particular lens and shouldn't be factored into the cost.

[I @ M]

Irrespective of where the tripod collar sits on the lens, you still have the total unsupported weigh of the camera body hanging off the mounting plate. I always assumed the balancing point was more to do with exactly that, balance, so you were not placing a front or back heavy set-up over a tripod head.

From a stress point of view, as I said above, it seems the better option to have 850gm unsupported, than the 1.3kg that my D600 + grip weighs. (I just weighed them)

Kevin, it is all to do with the amount of leverage exerted by the objects whether supported by a collar or supported by the camera body.
The actual lens mount is designed to support a load optimally with both mating surfaces in a vertical orientation. Of course it will support loads at all angles but by increasing overhang and subsequently leverage, the stress factor is magnified.
BTW, adding a grip to the body raises the centre of gravity, increases leverage angle and introduces more joints that can magnify vibration ( or maybe help dampen it ) and is not generally regarded as a sound move.

As a rough and ready example, where in the picture below is the most bending movement going to occur at the lens / camera mount? The tripod collar mounted example or at the camera body mounted example?
The actual "weak point" being the lens / camera mount joints between the load and fulcrum in both examples but with equal weights on either end of that joint one has more ability to exert leverage due to overhang.

This may or may not in line with the ability of the camera / lens combination to resist strain on that joint ( Nikon engineers know the figures, I don't ) but i will prefer to er on the safe side and stick to the makers advise to use a tripod collar on longish lenses.

Of course, all of this ties in with vibrations and harmonics and once again I feel that for most occasions the shorter overhang or more centralised mass will aid the quest for vibration free photography.

[Cage]

Andrew, many thanks for taking the time to give this old fart a quick update of the laws of Physics pertaining to levers and fulcrums.

Your diagram, plus a quick look at Wikipedia, clearly demonstrated the extra load exerted on the lens mount with the camera mounted on it's base. It also indicated that with all that weight in front of the balance point, the chance for extra vibration would be magnified. I guess that is why the collar is usually to the rear of the lens, depending of course on the lens configuration.

I really like the idea of the Nikon 70-200 f4 VR as a walk around lens, but I also know most of my shooting will be with a tripod.

I've been doing some numbers, as you do often when you are an OAP with an expensive hobby, and if I flick my Sigma 150/f2.8 and matching 1.4
T/C, I'll be around half way to the cost of this bit of kit.

Decisions, decisions.

Again, thank you for your time and patience.

[Lance B]

The Tammy 70-200 gets a good write up on Lens Rentals.

http://www.lensrentals.com/rent/niko...-usd-for-nikon

[arthurking83]

+1 ... in fact, if you're looking at the foot as the fulcrum then you actually have the weight of half the lens balancing against the other half + the camera. Not a great situation for minimising vibration. And the entire camera weight is still hanging off the mount putting stress on the lens mount.....

Maybe you have a different understanding of how tripod collars work, and none of mine work in this way, they're usually more like 2/3(front biased) 1/3(rear biased) .. but more importantly is that you don't attach the tripod collar directly to the tripod head. You generally attach it via a quick release plate, and this plate will be x mm long(where x = your preferred length).
the mere fact that this plate may have some length to it can mean that you now have the option to slide the camera/lens combo fore aft to balance the combination on your tripod properly.
This balance is what helps in minimizing undue force on the mount.
Going with your description, non or not many lenses would have tripod collars.. and lens makers would prefer all their lenses to hang out in front of the camera such as they will with the 70-200/4 minus tripod collar.

(Note too tho that I usually recommend against the Manfrotto RC2/RC4 type fixed QR plates, and this is part of the reason for that .. amongst other reasons).

..... It doesn't change the fact that it's not NEEDED for this particular lens and shouldn't be factored into the cost.

It should if the discussion is trying to maintain some semblance of like for like.
if a tripod collar exists at all, even if this is in the form of an optional extra, then you need to compare like for like .. and the fact is that a Tammy 70-200 and Siggy 70-200 all come with a tripod collar too.
Irrespective of your opinion on the usefulness of the tripod collar, your opinion only means something for your purpose(unless you have scientific data to prove your ideas) . so in a like for like comparison, the lack of a tripod collar is a negative point for the F/4 lens. Add $200 to the price for a better understanding of the value for money factor.


FWIW: The Canon mount version of the Tammy VC lens is now listed for $1100 on ebay(free postage) .. and I also noticed the Nikon mount version from the same DeeDuubUEye seller for $1999!!!

I reckon in a few months time the Nikon version will be selling closer to the Canon version(it has too, otherwise it'll fail against the Sigma) .. and if/when this does happen, I'll become more interested in it again.

At the moment, the Nikon VRII seems to be the better option overall.