Monday, June 19, 2006

Quick Change A Pentax SLR Lens

On Strobist, David pointed out that pros can easily spot an amateur photographer by the way they make their bayonet mount lens changes. To paraphrase him, amateurs look too carefully at their camera while they do it. They'll generally miss out on pretty good shots while spending too much time concentrating on getting the lenses off and on. The speed method is to carry the camera in your left hand and with your right hand you press the lens release and twist the lens off in one swift move, all without looking. Then, grab a new lens and twist it in with the same move.

With the lens twist method David describes, your right hand is doing double duty: you hold down the lens release button with the side of your index finger and keep it pressed down as you twist your wrist, letting the button slide along your finger. (See his illustration). Which is fine for Nikon and Canon users, but there's a little problem for Pentax users: the Pentax bayonet lens release button is not to the right of the lens, as it is for Nikon and Canon, it's on the inside left.

So how do you get the fluid twist and hold down the button all at the same time with a Pentax? Easy as pie.

Method 1: With your right hand still on the camera grip, you reach in with any finger and press the release button, while your left hand reaches in front and untwists the lens.

Method 2: With the camera in your left hand, pointing the lens towards you, fingers behind the camera, use your thumb around the grip to press on the release button, as you twist off the lens with your right hand.

Method 3 (similar to Canon/Nikon method): Hold the camera in your left hand and do the release & twist with your right hand, but use your lens hand thumb to hold down the release button, sliding the button along the inside of your thumb as you twist.

I dare say it's easier for Pentax users to make their lens changes quickly, because the placement of the lens release button is next to the camera grip, where you can have the hand that holds the camera do the double duty.

Aligning the dots: Lining up "the red dots" is a special trick in and of itself, which requires you grip the lens in a way that your fingers remember the location of the dot. When you pull a lens out of your bag, you should already know where the dot is, if not by sight, then either by marking your rear lens cap or by memory. And then you use your hand to guide the placement. For example, when you pick up a lens with your lens hand, keep your thumb near the dot and then when you're aligning the rotation of the lens to the camera's dot, just bring your thumb to the same spot every time. You can make it a habit.

A couple of extra things to keep in mind with DSLRs: avoid attracting dust to the sensor by turning the camera off while you make the change (eliminating the charge on the CCD), and, if you can, keep the camera facing away from possible air flow or dusty shirts. Special thanks to David's blog Strobist for his great writing on this topic.

Link: Strobist Quick Change an SLR lens


Anonymous said...

I just hold the body with my left hand underneath and press the button with my middle finger (of the left hand). Right hand just removes the lens.

The real problem with Pentax is that all the different (and old) available lenses have the red dot in very different places (on the end of the lens, on the rim, etc). I'm trying to learn which way around the lens goes by the aperture lever, but not all lenses have that either (I believe the M42 adapter doesn't?). That's what takes time, not removing the thing.

OK-1K said...

That's a variation on method 2, I suppose. However, you are confirming that no Pentax user needs to use their lens hand to press the lens release button.

I understand the dot issue, too, but it's not so hard to make that a fluid movement. I've added that information to the original post.

Eventually, I should take a picture to describe what I mean and add it to the above article. But the gist of this article is that you need to develop some memorized motions to do it quickly, and the lens dot is no exception.

Peter Barker said...

Regarding the red dot being in different places: admittedly all the lenses I possess have aperture linkages so I don't know how you'd get on with M42s, but I just hold the lens with the back towards me, rotate till the protrusion protecting the aperture pin is at 6 o'clock position, then slot the lens into the body.

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