Results tagged “lens” from kwc blog

They're here: 70-200 f/2.8 and 1.4x

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New Toy (the bigger one)

Two new toys arrived in the mail for me today: the Canon 70-200 f/2.8 IS USM and the Canon 1.4x extender. I've long been eying these as additions to my cycling photography arsenal, but I didn't view myself as 'worthy' of them at the start. Actually, price was probably more a factor. With the Tour of Missouri coming up, I figured now was the time to take the pocketbook plunge.

Experience matters for photography, but let's not kid ourselves. The person with the more expensive equipment will take better photos, at least for sports photography, where your photos have to been in focus to qualify. I took cycling photos for years with a film and analog Rebel, but it was the Canon 30D that immediately took things to the next level.

I'm hoping for the same sort of results with the 70-200 f/2.8 IS and 1.4x combo. The image stabilization in the 70-200 f/2.8 IS has a specific mode for doing panning photography, which is a popular staple of cycling photography (example). The extra advantage of the f/2.8 should also help in darker conditions, which my old 70-200 f/4 suffers in. One other bonus: weather sealing, which matters when you're trying to run around with a plastic baggie trying to keep the rain out.

As for the 1.4x, it's my compromise. It's been recommended to me that I pick up a 300mm lens, and there's been no lack of them at the finishing line of events that I visit. A 200mm isn't long enough in those situations and a 300mm collapses the depth of field better. Unfortunately, a 300mm requires man-of-steel arms to lug around. I've seen a photographer leave his 300mm in the media van rather than lug it around the course.

A 1.4x is cheaper and lighter. It will turn my 70-200 f/2.8 into a 98-280 f/4, which should fit the bill (an extender affects both the focal length and aperture). I was always worried that 1.4x or 2x extender would slow down my old f/4 lens too much, but the f/2.8 provides that extra breathing room.

I'll have several occasions in September to break the new equipment in. Hopefully it will perform well. In any case, it's another step towards guaranteeing that I never make money off of photography.

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Lenses are tough to make

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This video looks into the lens-manufacturing process at JML Optical. Somehow I thought it was a lot more automated than this.

Update: Mark Wallace of Snap Factory points me to the even more detailed Canon Virtual Lens Plant, which has video covering the lens manufacturing process from glass-forming to lens assembly. Canon's process seems even more complex. Just to get the glass for the lens, a glass mixture is blended from raw materials (different mixture for each lens), fused in a crucible, cast, broken apart, and recast into a sheet. Then the sheets are cut to the right shape/weight, ground, reheated, pressed into lens shapes, and annealed. Then you start the 'lens machining', i.e. actually grinding and polishing the lens. For this stage, the lens is rough ground with a diamond grind stone, fine ground with a diamond pellet platter (1/1000mm precision), polished, milled to the right diameter, and coated. The final lens assembly process is all expertly hand-done from the inside of the lens out. It's impressive how many steps have to go right to get to the final product. (got all that?)

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another crosspost from spare cycles

For my Canon 70-200 f/4 lens I keep in my head some approximate equations for calculating depth of field (DOF) at f/4:

200mm: 11.5 / (100/distance)2
70mm: 89 / (100/distance)2

These equations look difficult, but if you keep to easy distances you can rough it out. For example:

200mm @ 10ft: 11.5/(100/10)2 = 11.5/100 ~= 0.1 ft
200mm @ 25ft: 11.5/(100/25)2 = 11.5/16 ~= 0.7 ft

To convert to other f-stops, you simply multiply (e.g. f/8 is twice f/4).

When shooting with the 70-200, the DOF tells you whether you're going to be shooting a lone rider, a pack, or a really-in-focus gear shift. My Tour of California photos from last year are full of examples of overly optimistic DOFs for my slow Digital Rebel and trigger finger.

Chris Horner nears the finish-1 Ekimov nears the finish-1

above left: Horner's chest logo and thigh are in focus, but not much else. above right: I got luckier catching Ekimov's face, but the DOF is only about the length of his hands. If I had used a larger DOF, I wouldn't have tossed away as many shots. An alternative is to get a better camera, which I did.

My new 16-35 is adjusting my way of thinking on this. I can't extend my previous equation because at 100 ft, the DOF is infinity. In fact, at f/2.8:

16mm @ 10ft: DOF 21.4ft
16mm @ 5ft: DOF 3.52
16mm @ 1ft (minimum distance): DOF 0.12ft

At less than 5ft, it might be worth remembering, but a more useful calculation will probably be the hyperfocal distance:

When the lens is focused on the hyperfocal distance, the depth of field extends from half the hyperfocal distance to infinity. -- Photography, Phil Davis, 1972. source

Instead of trying to put one thing in focus, this is the distance to think about for putting everything in focus. For my 16-35mm this breaks down to:

16mm @ f/2.8: 15.7ft
35mm @ f/2.8: 74.9ft

This is much easier to remember and calculate than DOF. To get hyperfocal distance for other f-stops you divide (f/5.6 = half f/2.8).

This isn't field tested, but I'm thinking that it will be more useful to trade DOF for hyperfocal distance when I'm getting my 16-35mm shots. We'll see how it all works out after its inaugural run this weekend.

Thanks to the ever useful online DOF calculator

Branching out with a new lens

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crossposted from spare cycles

canon1635II.jpgThe newest lens in my small arsenal is the recently released Canon 16-35 f/2.8 II. Its bigger, badder, and more expensive than its predecessor. The Mark I was known for being a bit soft at the edge, so much so that some people have gone for the half-as-expensive 17-40 f/4 instead. The Mark II helps re-justify the 16-35's greater price tag. Of course, none of that really matters if you're shooting with a Canon 10/20/30D or Digital Rebel -- the 1.6x crop factor of those cameras cuts off all the fuzzy bits -- but lenses outlast the bodies they're attached to. One day I hope to have a full-frame camera for shooting architecture.

I was in a bit of a rush to get this lens because I want to break it in at Sea Otter this weekend. The wideness will be more useful for MTB shots and will also help me get some nice panoramas of Laguna Seca. It will also be useful for road shots where I'm standing really close to the action.

Rather than recommend the same course of action to others, I'll list the pros and cons I debated in choosing this rather extravagant purchase.

Pros: * f/2.8 is fast and you'll need if you are planning on shooting in the woods or in bad weather * better edge sharpness than the Mark I, though not applicable for 1.6x crop cameras * 1.6mm wider than the 17-40mm f/4L on a 1.6x crop camera

Cons: * $300-400 more than the Mark I * Over twice as expensive as the 17-40mm f/4L. In fact, you could almost buy a 17-40mm f/4L and a 70-200 f/2.8L for the same price.

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Forget the Canon 70-200 f/2.8, I'm skipping straight to the Sigma's 200-500mm f/2.8. All the other photographers will have to get out of the way when you wield this 35 lb behemoth -- if it doesn't break your back... and wallet.

If that's not enough grab for you, it comes with a 2x extender to turn it into a sick 400-1000 f/5.6. It even has room for a LCD with focal length and distance readout.

Post-race lens purchase?

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My Canon EF 70-200mm f/4L lens was a champ during the Tour of California. Once I got a decent camera body to stick it on, its true quality shined like a diamond. But I have a whole void for < 70mm that I need to fill. Milling about the start area in Santa Barbara as well as the post-race interviews, it simply wasn't possible to frame a lot of shots unless I wanted closeups of nose hair.

One of the longest discussions I had during the Tour of California was asking another photographer for recommendations as to which lens to get next. Two in my book ranked highly as contenders: the Canon 16-35 f/2.8L and the Canon 17-40 f/4L. The 16-35 is twice as expensive for the extra 1mm of wideness (1.6mm on my 30D), but the f/2.8 could come in handy if I start using it for mountain bike races. The 17-40 has an extra 5mm (8mm on 30D) of reach. Another plus for the 17-40 is that is much sharper at the edges than the 16-35, though this doesn't matter as much if you have a 1.6x crop factor camera (like the 30D). This photographer actually knew colleagues who turned in their 16-35s for 17-40s because of this sharpness issue (money wasn't an issue).

Canon may have settled the debate for me last week if I can locate the money:

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The new Canon EF 16-35mm II is designed to improve the sharpness issues of its predecessor. Not much is known about this lens yet as I have not seen any hands on reviews. About the only complaint I see with the new specs is that it now requires an 82mm filter instead of 77mm filter, which will cost you a few extra bucks... but you should have a few extra bucks if you can afford this lens in the first place.

Canon is now offering double rebates until January 13th. Double rebates means that your rebate doubles if you buy two items, e.g. if the 5D is $300 off, you get $600 if you buy another eligible Canon item. This isn't quite as good as the triple rebates that they sometimes do, but it is catchy enough to make me want to hide my credit cards until the rebate is over. Must... resist... more... lenses.... and... speedlite...

You can view the rebate details on Amazon -- the rebate applies wherever you buy the equipment.