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|| SportsShooter.com: Member Message Board
Lens calibration questions
Jeff Brehm, Photographer, Photo Editor
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Charlotte | NC | USA | Posted: 9:34 AM on 08.17.10 |
->> Forgive me if I've missed another thread on this, but a search didn't show me any answers to my questions.
1.) Is the ability/need to calibrate lenses a benefit or curse of modern technology? Only recently have I seen lens calibration discussed. Were our lenses and bodies just as out-of-whack five years ago and we didn't know it/notice/care/have the ability to fix it? Or is it that the new gear requires much more micro-adjusting?
2.) I think every discussion I've seen so far was about calibrating Canon equipment. I swear I am not trying to fan the flames of Nikon vs. Canon here, but do Nikon users experience a similar need to align their lenses?
3.) Am I the only one who thinks that the camera and lens ought to be properly matched and work the way they're supposed to right out of the boxes? |
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George Bridges, Photographer, Photo Editor
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Washington | DC | USA | Posted: 10:03 AM on 08.17.10 |
->> Jeff,
I'll answer your last question first: Yes, lenses should work right out of the box. No adjustment.
For question one. Not sure of the cause. I think it is the newer technology, more sensitivity and more moving parts in lenses. In the "old" days a lens focused by moving elements along like a screw -- along a helical bore -- essentially. Everything was tied down. Now with vibration reduction, ultrasonic focus etc, things move differently and, I guess, can shift around a bit and get out of tolerance. It may also have to do with how chips "see" the image compared to film as well as the fact the image is broken down into a bunch of digital particle and then reassembled on the computer or in print whenever you ask. All this can lead to seeing sharpness issues easier. Plus, you are not running it through another lens on the enlarger to make a print. But anyone who has ever shot with a Leica or some good, older manual-focus primes can tell you that you could get negatives so sharp you could cut yourself.
As for the Nikon vs. Canon: I've never calibrated my Canon gear and have little problems with it. |
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Randy Abrams, Photographer
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Bath | NY | US | Posted: 10:04 AM on 08.17.10 |
| ->> I agree with your number 3! In regards to #2 I just got my 300/2.8 back from Nikon service to get the AF fixed. I had it at -16 using AF fine tune on my bodies and it still wasn't quite right. I think the modern lens have so much technology in them (computer chips for focusing and sending distance information, etc) that they have a tendency to get out of alignment easier than older lens with less elements and such. |
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Stanley Leary, Photographer
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Roswell | GA | USA | Posted: 10:13 AM on 08.17.10 |
->> Lenses and cameras are calibrated with certain tolerances. If a lens is in tolerance and a camera is in tolerance together they can create not such a great combination.
If your camera is say for example -3 and this is within the tolerance of acceptance on an assembly line and your lens is +3 off the assembly line then together they may be off noticeably enough that if you calibrate that lens to that camera you can improve the results.
I have found that most all my lenses were just enough off with each of my cameras that once I calibrated each lens with each camera I noticed an improved quality of sharpness in my photos.
The issue isn't about perfection out of a box, but the combination of tolerances in combination with each other that can cause the problem.
this is why often if you are having a problem with a lens or camera the manufacturer repair center would like to see both to diagnose the problem.
Hope this help clear up some of your questions. |
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Dan Root, Photographer
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Portland | OR | USA | Posted: 2:03 AM on 08.23.10 |
->> I used the Lens Align kit for both my Canon 1D MK IV and my 1Ds MK III.
http://www.lensalign.com/
Made a huge difference.
One thing that many folks do not realize is that cropped sensors have less depth of field than full frame sensors. This is why I am hoping that Canon will make a full frame 1D version one day like Nikon does. I can't explain the physics behind it, but if you see the charts on the Lens Align Distance Tool page, you can see that you lose about 20% of your DOF when you go to a 1.3x crop sensor. With a 400mm f/2.8 lens, 60 ft. from subject, the DOF for a 1.3x sensor is 10.4 inches, and for a full frame sensor it is 13.5 inches. Or you can say you gain almost 30% more DOF with a full frame sensor over a 1.3x sensor.
See here for the Distance Tool:
http://www.lensalign.com/ldt/index.html
The other thing I noticed is that when I have a 400 f/2.8 on my 1D MK IV, and shoot at f/4 or less, I need to pay attention to trying to get the AF point right on the subject's face. If I used the center point for my AF point, and the AF point was on the subject's mid section, that was in focus, but the face was out of focus. I then remembered that I was pointing the camera down, so the plane of focus was tilted, so I got the foreground in focus, like the grass in front of the subject, and his shoulder behind his head was in focus, but his face was out of focus. This seems less of a problem when I use the same lens on my full frame sensor 1Ds MK III. I think that is why a lot of folks using the Nikon D3 get more shots in focus than the 1D MK IV. Of course, this is my humble opinion, and not meant to spark a Canon vs. Nikon debate. Both systems have their own plus and minus factors.
So in summary, using the Lens Align kit will helped me out a lot. In fact, my f/1.4 and f/1.2 primes are right on at wide open about 80% of the time. When before using the kit, it was about 50% on a good day.
Hope this helps. |
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Chuck Steenburgh, Photographer
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Lexington | VA | USA | Posted: 11:34 PM on 08.23.10 |
->> At the start of basketball season two years ago, I found one of my D300's couldn't focus worth a crap. After initially panicking, at halftime I started experimenting with AF adjustment and dialed in a pretty extreme value (75% of max if I remember) and voila, focus was fixed.
That lasted about a year, and then AF became very erratic...so I sent the body in for adjustment (Mack extended warranty, no charge) and it came back nice and sharp with no AF adjustment.
Back in my D70 days, my then-new Tamron 28-75/f2.8 had an awful backfocus problem. I had no choice, then, but to send it to Tamron for adjustment (that lens had something of a reputation for misalignment out of the box). But AF adjustment might have made it a useable lens without a trip back to the factory. |
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Dan Megna, Photographer
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Coronado | CA | USA | Posted: 4:28 PM on 08.24.10 |
->> Jeff - I agree that I would expect lenses would be dialed in right out of the box. But with manufacturing being what it is I don't think that's realistic. I suspect that's why adjustments tools are being added into camera menus. So I too began to ponder the calibration question a few months back after reading an article. One afternoon I decided to do a little casual testing.
In the end, using my D3 and D300S, I did find, especially with my 200-400 VR, I was able to improve on the 'out of the box' focus sweet spot. I had similar findings on a few of my other lenses. That particular 2/4 needed a tweak of +12 on the D300S to nail it. The D3 also needed a little adjustment but not as much. |
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Jeroen de Jong, Photographer
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Waalwijk | _ | Netherlands | Posted: 2:49 PM on 08.25.10 |
->> I agree that the stuff should work perfectly out of the box.
Micro-adjustments are fun, but I think it's a pain in the *ss to make the adjustments right.
My 70-200 was so unsharp after 1,5 years because of all the shaking in trollies and others that micro-adjustments didn't help anymore.
Today CPN callibrated 80% of my gear (for free, within one day, kudo's for that)
Haven't tested it yet, but last time (2 years ago) it was an improvement like brand new gear. |
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