Can someone explain asymmetric movements and why they're better?
Can someone explain asymmetric movements and why they're better?
Great read.
We currently have an interesting discussion on assymetric movements, in the UKLFPG forum : http://www.lf-photo.org.uk/forum/viewtopic.php?t=819
Nice article, but it doesn't quite explain why asymmetrical movements are better, or more convenient, than symmetrical ones. I'm reading it more like "why asymmetrical movements are better than no movements at all" (especially those two examples).
With asymmetrical movements, you pick a part of the subject plane that falls on the dashed line (the tilt or swing axis, that is). Then you use this point as a pivot - focus on it and start tilting, and it will stay focused while the other parts of the subject come in focus, too.
With symmetrical movements, you pick a part of the subject plane that happens to fall in the center of the frame. Then you use this point as a pivot.
So, where's the difference? Why is an off-axis pivot better, or more convenient?
I'd understand the convenience if you could pick a tilt/swing axis of your choice (I mean, place the tilt/swing axis wherever you want). But, if I understand correctly, the tilt/swing axis is still fixed, only moved a little sideways. Am I missing something?
Depends on the camera. With a Linhof Master GTL, you can move the tilt and swing axes.Originally Posted by VladSoare
I'd understand the convenience if you could pick a tilt/swing axis of your choice (I mean, place the tilt/swing axis wherever you want). But, if I understand correctly, the tilt/swing axis is still fixed, only moved a little sideways. Am I missing something?
With a Sinar P or P2 what you can do if the axis isn't in a convenient place is use the rear rise/fall/shift movements to put the axis where you want it and measure the tilt/swing angle on the rear standard using the protractor scales, then you can leave the movement on the rear standard and return the rise and shift movements to the original composition, or transfer the tilt/swing to the front standard using the front standard scale and return the rear standard to the neutral position, and return to the original composition with the rear rise/fall/shift movements, and in either case the tilt/swing angle will not change. It sounds more complicated than it is, and once you get the hang of it, it's pretty quick to find tilt and swing angles this way.
I see. That makes sense.
But then, you can do the same with "normal" (symmetrical) axis tilts/swings. No need for asymmetrical movements.
As I see it, if you have asymmetrical movements and find a convenient pivot on the dashed line, great. If you have central axis movements and find a convenient pivot in the center of the frame, great. Otherwise it doesn't really matter which kind of movements you have, because you're going to be refocusing (or moving the tilt/swing axis by shifting the standard, like you say) anyway. Is this correct?
My point exactly! I just can't see why you "need" asymmetric movements, which is the reason why I started the discussion in the UK forums.I see. That makes sense.
But then, you can do the same with "normal" (symmetrical) axis tilts/swings. No need for asymmetrical movements.
Depends on the camera as well. A Sinar P/P2 is designed so that you can find the tilt or swing angle without having to refocus and repeat, because the rear tilt/swing axes are really aligned with the focal plane, so you can see what's in focus as you tilt on the groundglass as you tilt, without having to guess, refocus, try again, etc. Then there are levels and scales on the camera so that after you've found the tilt angle on the rear standard, you can decide whether to keep the rear tilt or apply the same movement to the front standard.
Not all cameras have rear axis tilts, and if you have rear base tilt, the tilt axis is often below the frame. If you have rear axis tilts, with the tilt axis in the center of the frame and aligned with the focal plane, and you have a convenient way of measuring the tilt angle on the rear standard and applying it to the front standard, then you can use it like a Sinar P with asymmetric tilts, but a lot of cameras aren't actually like this.
That said, with experience, the normal iterative focus method works pretty quickly as well, so it's not as if you can't control the plane of focus without asymmetric movements. Having cameras of various types, I do think the Sinar P is a bit faster to work with for tabletop shots, where swing and tilt can be more complicated, and that's really what it's designed for, and it's also handy for making a quick adjustment with a portrait subject. For landscape and architecture, asymmetric tilts don't seem like as much of a time saver.
Having read and participated in the thread on the UKLFPG website and having used LF cameras with base, centre and asymmetrical movements here's my take:
Using centre or base tilts requires the user to go through a process of focus, tilt (or swing), focus, tilt, focus, tilt, repeated until the near and far points on the composition are both sharp. This can take a number of moves - especially with "complex" subjects.
However, with asymmetrical tilts or swing this need to focus, tilt, etc etc is negated due to the asymmetric placement of the axis. So, you simply focus on the bottom gridded line (the background) and then employ rear asymmetric tilt until the part of the scene lying on the top gridded line (the foreground) is sharp and that's it! There is no need for the focus, tilt, focus, tilt ad infinitum procedure to get the background and foreground sharp! The scene is sharp!
It is also important to realise that ANY part of the scene falling on these gridded lines can be used - foreground, background it doesn't matter; just focus on whatever lies on one gridded line and then apply the movement until the part of the scene lying on the opposite gridded line is sharp! Couldn't be easier
A question for Frank - "As for a marketing ploy" I disagree completely - I think that asymmetric movements are a godsend! A bit like autofocus for LFI use an Ebony 45SU and being a non-folder combined with asymmetric movements I found the camera design a real help in adverse conditions. The speed and accuracy of the movements means that I KNOW that everything that I want to come out sharp will do just that. I was able to take photographs in a very windy Iceland last year in a fraction of the time that it would have taken with a folding camera with regular movements and I was able to concentrate on composition rather than "would the near and far be in focus" and get the camera back in the bag before my fingers fell off!
As far as the camera being a "status symbol" and "overkill" I would suggest that probably every LF camera built is overkill apart from (say) the Ebony RSW? Do any of us use even a fraction of the movements available on our cameras? Probably not!
Having laid out a load of cash for my Ebony 45SU back in 2002 I am one happy camper. I would not go back to a camera without asymmetric movements because I have experienced the benefits first-hand and not relied on people simply dismissing a feature they've never even tried
I challenge anyone to peer through the ground glass of my Ebony and not reappear with a big grin on their face when they see EXACTLY how useful this feature is! They will then be looking to sell a kidney to buy one!
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