D90 backfocus with primes
I have problem that both of my primes do massive backfocus. I have tested this with focus charts many times (using tripod, enough lights and so on.. so i'm sure that there is backfocus). Those two primes do backfocus even in outdoor, in fair sunlight, where everything should be "easy" for the camera.
Primes that I am using are 35mm f2 AF-D and 50mm f1.8 AF-D. So they are using "screwdriver"
I also have 18-105VR AF-S, and I can't say that it does backfocus. It's hard to tell if it does, because DoF is so large, but i'm 99% sure that it doesn't do backfocus.
So what I can do? I don't wanna pay several hundred euros to get these "low-end" gears in line. I'm anyway planning to change to FX, or get the 17-55 f2.8 Nikkor (the magic-glass ). Should I just dump these primes? I have read that I can correct D90's focus from those two screws behind mirror (one for MF and one for AF). But if I touch to AF-screw, I will ruin the 18-105 focus, right? There are no AF fine tune in D90
BTW: with MF I think that focus is in place.
#1. "RE: D90 backfocus with primes" | In response to Reply # 0
Covey22 Charter MemberTue 28-Aug-12 01:53 PM
I would not recommend DIY (do-it-yourself) AF tuning by fiddling with the camera's innards. Have you considered sending it in for service with your lenses? All told, it will probably not cost more than a new short prime lens assuming it's all just adjustment work? Cheaper than a 17-55 for sure.
#2. "RE: D90 backfocus with primes" | In response to Reply # 0
MEMcD Nikonian since 24th Dec 2007Mon 03-Sep-12 12:47 AM
Trying to adjust the camera and or lenses yourself will more than likely wind up being significantly more expensive than sending the camera and all three lenses in to Nikon Service for adjustment.
Good luck and Enjoy your Nikons!
#3. "RE: D90 backfocus with primes" | In response to Reply # 2
Thu 04-Oct-12 04:19 AM
I didn't listen your warnings.. and usually this is the part where everything starts to go wrong but not this time!
My D90 is now focusing like angel, and I can again fall in love my fast primes and have huge crush to my new Nikkor 17-55 f2.8!
1. Print focuschart, and learn to use it before this "operation" (like one @ http://focustestchart.com/chart.html )
2. Read manual for focus adjusting (D70 D80 D90 & D300 confirmed) like: http://www.howtoshot.com/82/how-to-fix-front-focus-nikon-d90-d80-back-focus-problem/ or http://leongoodman.com/sergei/backfocus.htm
3. Remove lens
4. Locate AF screw behind mirror
5. Keep in mind the location of the screw, then turn it as much as other direction you can by using hexagonscrewdriver (30 degrees?)
6. Put fast prime or some f2.8 lens back on
7. Verify focuspoint using chart
8. Was focusing going wrong or right direction?
7. Repeat parts 5-8 until you microadjust focusing to right position
I got everything 95% right in just a 10 minute! It took a while, let say 30min to microadjust everything 98% right (focus can't be 100% accurate.. even in body that is straight out of the factory, atleast usually).
Now my D90 is all good again, and I won't miss other important shots and my clients are more merrier
#4. "RE: D90 backfocus with primes" | In response to Reply # 3
alubchenko Registered since 01st Nov 2012Tue 20-Nov-12 12:06 PM
verdict, it's good you solved it yourself. I had the same experience with 2 D90 bodies, which had backfocus on fast lenses. Interested in how many bodies has this problem. When I used a kit 18-105 vr Nikkor lens i couldn't notice any backfocus probles, 'cos of small maximum apperture (3,5), so i found out backfocus problems when swithed to 50mm 1.4D Nikkor.
I had terrible feelings about my new lens, because when i used it wide opened i had all shots out of focus... After some days of googling i solved the problem the same way you discribed above, but i'm still curious if Nikon tunes DX bodies focus for DX lenses or I just couldn't see backfocus problems in apperture set to 3,5 and smaller? May be the problem is obvious only on fast lenses?
#5. "RE: D90 backfocus with primes" | In response to Reply # 4
Tue 20-Nov-12 01:00 PM
I think that this is common problem with D90. I also own 18-105 and didn't notice the backfocus, because slow aperture. When looking really carefully those 100% crops, you can see the backfocus even with that lens, especially in tele.
I also tought that dx-lenses could solve this, anf problem occurs only with screwdriver lenses like AF-D primes, but no. My beloved Nikkor IF-ED 17-55G SWM DX f2.8 did the same!
I'm now happy owner of D700, as much as loved D90, D700 is so much better in every ways.
Just tune that micro-focus setting more, you will get it right!