Adjustability Ain't All It's Cracked Up to Be

A photo like this might look pretty good at first glance. The problem is that I was trying to focus on the bridge of this violin, not 15mm or so behind it.

What would you rather have: a camera that lets you micro-adjust the point of focus for each lens in your arsonal, or a camera that comes factory-calibrated, period? A camera that lets you adjust the JPEG color rendering to your taste or one that produces what most people agree to be excellent color right out of the box? A camera that lets you adjust the white balance or one that does a marvellous job when set to auto-white balance?

A year or so ago I would have preferred the more adjustable camera. Now I'm not so sure. One of the reasons--although certainly not the main one--I bought my Nikon D7000 was because it has the forementioned micro-focus adjustment feature. I never thought I'd need it; and in fact, as long as I was using my older Nikkor lenses (a 35mm f/2D, 50mm f/1.8 AIS, and 85mm f/2 AIS) the focus was spot-on.

That all changed when I bought a new 50mm f/1.8G. It took me months to discover that either it or the camera was backfocusing, and badly. I had to dial in -10 units of compensation to get accurate focus. The good news was that I could do this without having to send the camera and lens in for warranty repairs or calibration. The bad news is that it was necessary. In effect, Nikon or any other camera manufacturer that includes this "feature" can get away with sloppy quality control because it's now the user's responsibility to properly calibrate the focus for each lens.

Even without double-clicking on this image, you should be able to see that the focus is on the basket of raspberries in the foreground, which is exactly where I wanted it and exactly what I got, with no need for micro-adjustment.

I would rather have a camera and lens system that doesn't need calibration. That was certainly the case with the Canon EOS 5D Mark III I used this summer. As one would expect with a camera that retails for around $2800 body only and has a 61-point AF system, the 5D Mark III's AF accuracy was consistently excellent, regardless of whether I was using old lenses or new, with fast apertures or slow, in bright light or low.

And lest you think this is a slam at Nikon, I also experienced exceptional AF speed and accuracy with the Nikon V1. There's probably a much larger tolerance for error between the V1's 1-inch sensor and the APS-sized sensor used in the D7000. Even so, it's disappointing when the AF in a $1000 camera underperforms the AF in a (now) $400 camera.

The point isn't really the comparisons. It shouldn't surprise anyone that the full-frame EOS 5D Mark III is a much better camera than the less expensive Nikon D7000 and makes the Nikon V1 look like no more than a well-designed toy. My point is that I would take "excellent right out of the box" over "adjustable to your heart's content" any day. Would you, and if not, why?

Comments

[Matt]

"Vertrauen ist gut, Kontrolle ist besser!"

[Tim]

I'll admit this whole focus-micro-adjustment business has kinda passed me by, being as how I don't shoot situations where I'd rely on AF to focus for me. But would I be right in thinking it's a feature of the (camera/lens) combination rather than camera or lens on their own? If so, by what mechanism does it arise and why can't manufacturers produce a consistent focussing experience, at very least for all their own branded stuff?

[Nick Susatyo]

I prefer to have things working out of the box.

A few years ago I owned a 5D II for a good 2 years, and I too was thinking that microfocus adjustment would be a great feature. It took me a while to figure it out, and whether I actually need it.

Then I came across official Canon's white papers or an article from Canon's website that says something like: Microfocus adjustment is normally not necessary. Most lenses that came out of factory (probably >95%) are meant to work without any microfocus adjustment.

So instead of going ahead with adjusting each of my lens, I leave it as it is. And anyways, I do use those lenses on other bodies as well, such as the EOS 620 and EOS 3, which obviously doesn't have a microfocus adjustment. So I actually need my lenses to work across all my bodies - otherwise it needs to be adjusted by Canon anyway.

And re useable WB out of the box - this is why I love film. The WB of film is fixed and I won't accidentally set Tungsten when I'm shooting on the beach ;) (admittedly this is the mistake I most often commit when using a digital camera).

[John Krill]

I guess I'm better off for buying the Nikon D5100. Being the D7000's little brother it doesn't have a lot of the options that the D7000 has including focus adjustment. But my primary reason for getting the D5100 was weight. The D5100 is smaller and lighter than the D7000 but includes the same sensor and processor.

It helps that it is a lot less expensive.

Now I need to replace my lens. I'm using the Nikkor 18-70mm. Any suggestions?

[Robert Chapman]

I never worried about micro-adjusting focus until my camera club purchased a Lens-Align. Then I checked my lenses and all, except one, were spot-on (I shoot Nikon). When a group of us Nikon shooters did a quick check, the only lens that had significant issues was a first-generation, well-used 18-200. I'm not going to defend Nikon vs Canon here but these cameras and lenses, even the expensive ones, are mass produced with certain tolerances - there will be sample to sample variation in any brand. If I notice a focus issue, whether out of the box or after a few years' use, I like having the ability to fix it. It's amazing, considering the optical/electronic/mechanical process involved, that the cameras manage to focus at all!

[Dan Paris]

I don't mind paying top dollar for Nikon's pro-quality FX lenses but for that kind of money, I expect them to perform out of the box. Fortunately, most of mine are in the 0 to -2 range and for that I'm happy, but my venerable 17-35 f/2.8 (my favorite all-time lens) needs a lot of adjustment. Worse, I've found that it has to be retested once a year because it seems to be "creeping" towards greater back-focusing. Kind of like my eyesight, I guess. While I was away over Christmas, I discovered that it was back-focusing again. It's now up to -8. I wouldn't be surprised it it hit -9 this time next year. But I guess that's why I like this old lens - it kind of reminds me of me... a little heavy in the middle, a little paint receding off the top, and now in need of glasses. Thankfully, my camera can adjust for the latter.

[Brad Calkins]

This is one of the advantages of mirrorless or Contrast based systems - accuracy does not depend on accurate alignment of the phase detection sensor with the sensor plane. It is also the reason the Nikon V1 can do do well - the phase detection system is part of the sensor.

There is a good article here on why you shouldn't assume from one body/lens combination that it was made to tighter tolerances: http://www.lensrentals.com/blog/2010/03/this-lens-is-soft-and-other-facts . They also have an article on how the MkIII with specific lenses has much more accurate phase detect focus, perhaps proving your point that the MkIII is actually better designed: http://www.lensrentals.com/blog/2012/07/autofocus-reality-part-ii-1-vs-2-and-old-vs-new

I do think it is just 'improvement', though, and this is jut an example of a new body having technology that hasn't trickled down yet, rather than it being an issue of paying more for better tolerances.

[Gerry Winterbourne]

Like a lot of people you think that "quality control" means making things perfect. It doesn't: it means making sure things are within the chosen engineering tolerances.

Those tolerances are set to give a balance between price (cost) and accuracy. The relationship is non-linear: to get things perfect needs finer tolerances, more testing, more individual fine-tuning (or wasted cost of rejects) and each adds its own layer of cost. That's why precision lenses like Leica are so expensive.

I'd like everything to be perfect too, but I can't afford the price.

[Tim]

Ah, thanks to Brad Calkins for hinting at why it occurs.

It does still leave me wondering a little as to the circumstances in which engineering tolerance should cause such a problem, but it's less important now I understand why (and it's pretty far removed from my pondersome shooting style anyway :)

[Tim]

I've been using the Canon 5D MK2 since it came out.
I photograph my kids with fast lenses.
I found that the keeper rate was pretty awful even after micro adjustment. Good to hear the MK3 is better.
I also found the DSLR concept of a diamond shape focus area really dumb because it's not designed to respect to the rule of thirds.
Now I'm shooting with a micro 4/3 camera. Auto focus is easily as fast as my DSLR and face recognition means my shots are eye lash sharp and composed just the way I want them (not hamstrung by a diamond shape focus area) saving time cropping.
Gotta love the technology that apparently doesn't require micro focus adjustment, is able to recognise faces and focuses quickly and accurately on the eyes!
Don't miss the weight either.