The case against the Arca-Swiss L-Plate

20Jul08

I’ve been using an Arca-Swiss quick release L-plate from Really Right Stuff since I first bought my Nikon D200. (For those that don’t know what the Arca-Swiss mounting system or an L-plate is, please read this and this.)

Before that, I was using a regular flat plate, and the move to the L-plate showed me how much more convenient it was, and also how it seemed more stable, because the camera is centered over the tripod rather than off-centered.

The case

Now recently on Fred Miranda’s photography, I read a posting that L-plates aren’t really as stable as conventional wisdom might imply, because instead of having a thick ballhead column connecting the camera plate to the tripod, what I have now is a flimsier bracket. This is apparently most problematic with longer lens without tripod collar, such as the consumer 70-300 lenses, and also it’s more evident at speeds around 1/30s.

How could this be? I checked my L-plate and it seemed sturdy enough. But just to be sure, I tested it.

My Tripods

I have two main tripod setups. The larger one (below left) is a 4-section Gitzo G1228 carbon fiber tripod with Arca-Swiss B1 ballhead. Without extending the center column, my D200 comes up nicely to the eye level of my 5’8″ body. The smaller setup (below right) for traveling is s 4-section Gitzo T1540GT carbon fiber tripod with Giottos MH-1001 ballhead. This is quite a bit smaller and lighter, and doesn’t quite go high enough without the center column.

Test setup

I put one of the junk mailings from Citibank on top of my thermostat on a beige wall. I then setup the tripods facing the subject with the natural light behind me. The tripod legs were fully extended, but the center columns were not. I did not try to get the same point of view between the shot with the L-plate and the shot flipped over. There will invariably be differences in composition, but I didn’t believe that would’ve changed the outcome. I used my 70-300 f/4.5-5.6G IF-ED AF-S VR (no tripod collar) set at 70mm, its sharpest focal length, with VR disabled for the test. I took two shots of each at ISO 100, aperture of f/10, and speed of 1/15s, and picked the best of the two for each configuration. All shots were taken without mirror lockup (the D200 doesn’t have a true mirror lockup, but does have a setting to bring up the mirror a fraction of a second before firing — I did not enable this as I don’t normally use it). The shots were taken with the timer set to shoot 2s after I depressed the shutter button. I could’ve used a cable release, but didn’t think it would change the results.

Results

Let me first make the caveat that this is by no means a scientific test, and I’m doing this for my own benefit and am sharing the results.

OK, I found that the L-plate showed diminished sharpness with my 70-300mm lens using either tripod setups, with the smaller setup showing greater blurring.

The images below are sized differently because of the difference in distance between the camera and subject with both tripod setups — I had the smaller setup closer to the subject. Also, the background of the subject is supposed to be white, but to get 1/15s, I had to underexpose it, resulting in a grey background. This should not affect the conclusions.

Here are the 100% crops of the photos using the larger tripod setup. L-plate shot is on the left, and flipped over shot is on the right.

Here are the 100% crops of the photos using the smaller tripod setup. L-plate shot is on the left, and flipped over shot is on the right. Notice the even greater detrimental effect of the L-plate.

A side conclusion is that under perfect condition — no wind, delay release, etc. — the smaller tripod set up can produce as sharp an image as the larger setup.

Different Lens

Now, my most commonly used lens is the 17-55mm f/2.8G Nikkor. So is that affected as well? Yes and no. With the larger tripod setup, I could not tell a difference, but with the smaller setup, there is a *very* slight reduction in sharpness, but it’s quite minimal. With even lighter lens, this might be a moot point.

Conclusion

So yes, based on my usage, the L-plate does affect image quality of certain lenses. To use any of the bigger lens without a tripod mount, such as the consumer 70-300mm, I definitely would want to avoid using the L-plate in vertical format and flip the camera over instead. For other lenses that are smaller, the effect might be neligible.

For some, even the *hint* of a reduction in image quality is unacceptable; for others, convenience matters more. For me, I’ve already bought the L-plate so I’m sticking with it for now, although I might not use it in the vertical format as much. But for a future camera, I’m saving some cash (over $100 it seems) and about 2.7oz in weight, and going for the regular plate instead.

Cheers!

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7 Responses to “The case against the Arca-Swiss L-Plate”

  1. I think your tests are OK as far as they went, but I think you should use a wider range of shutter speeds and repeat the series several times. Many camera and tripod setups will give reduced sharpness around 1/15 (+/-) — which is what that special setting to lift the mirror is for. But I would do more tests, for sure, and if your bracket results in some blurring you will want to know it. I, personally, even for photos that donot require super sharpness, would dump the bracket. I refuse to invest in expensive glass and camera and then have it do less than it could because of an accessory!

    I guess you know why 1/15 can be a troublesome setting. When the mirror flops up and the shutter fires, there is motion and newton’s 3rd law kicks in (opposite and equal reaction).
    At slower speeds (1 second?) the camera has time settle down after the mirror jump and the jumpy frame is a iny part of the exposure and negligle. For exposures shorter than 1/15, the shuuter is closed before the bump takes effect,

    And maybe this is a problem with just once lens, which because of length and eight balance acts like a pendulum out there.

  2. Ooops, please excuse typos in previous message.

    dont = do not

    eight = weight

  3. 3 TopL

    Hi David,

    Thanks for your comments!

    I could’ve used a wider range of shutter speeds, but I wanted to see what could happen at the “worst” speed. Also, while the mirror would contribute to the blurring, I’d expect that I’d get the same blurring with both the L-plate and flipped settings, so the baseline would remain the same, and results would still be valid.

    I do agree with you that it could be a problem with a particular lens as well, but that’s my point actually. I chose what I thought would most clearly show a difference in behavior, my 70-300 without a tripod collar. I also tested my 17-55, which is my most used lens, and I also see that to a much smaller extent, but I still do see it on my smaller tripod setup.

    I was seeking to find out if I should stop using the L-plate in vertical format using my camera, lenses and tripod setup, and my testing and results, though not comprehensive, was enough to confirm that.

    Cheers,
    Top

  4. I’d be interested in knowing whether your L plate vertical bit touches your camera body (i.e is there a gap between the L plate and the camera body at the side). If there is a gap then your camera is like a tuning fork.

    If you can, ensure that these parts touch firmly – this should give a *lot* more stability..

  5. 5 TopL

    Hi Tim,

    Yes, with the Really Right Stuff L-plate I had, it did have a little space between the camera body and the vertical plate. There’s no way to adjust that as the hole to secure the plate to the camera is fixed.

    Cheers,
    Top

  6. 6 Adrian

    Hi – old post I know, but two thoughts:

    “D200 doesn’t have a true mirror lockup” – um, mine does. You set the dial to MUP (under the ISO button), press the shutter half-way and voila, it locks up – press again fully to take the shot. The delay option you mention can be set via menus (handy when time/timing is an issue).

    This test shows just how much mirror ‘slap’ can affect sharpness:
    http://www.ophrysphotography.co.uk/pages/tutorial_mirrorslap.htm

    Found the post because I’m researching which L bracket to buy. I’d be curious to see what your results would look like if you re-ran the tests WITH mirror lock-up. In my case (closeup garden photos) I’m often working with long lenses at slow shutterspeeds and anything that reduces vibration is a plus.


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