Hello everyone...Happy New Year! Well, this is my first post in this year so wanted to wish you all a great year ahead, and more importantly HAPPY SHOOTING!
So, here is my question....a friend of mine was having investigating his D7000 camera for focusing issues (front focusing) and wanted to try my 50mm f1.8 lens to try out. He came back saying that my lens constantly showed front focusing every single time he tried it and his 35mm f1.8 actually performed better and he had to manually adjust his sharpness to +20 (from +10) and my lens started showing excellent results. I have not done any of my tests on this lens (ever till date) on my D300 camera and seem to be faring well.
So how can I test the lens for sharpness / focusing issues. Is there a easier way to confirm this? Appreciate all the help and guidance.
PS: Are there any known issues with this lens w.r.t focusing/sharpness?
AF fine tune tweaks are a slippery slope at best. If you're not shooting the lens with his D7K don't worry about it.
There are issues with some D7K's, yet most NIB and refurbs are great upon opening...no adjustments necessary.
I have 4 bodys and 12 lenses and the only one that needed AF fine tune was the 135 f2 DC. Keep shooting and enjoy!
As trench' says, it would seem like there's quite a few D7000 bodies out there that has some kind of problem - almost ALWAYS front-focus! - regarding the AF system. For some users, this only concerns AF-S (G) lenses for some unknown reason.
One thing that is fairly well known is that the D7000 is sensitive to colour temperature - very low WB temps and AF-S lenses tend to give front focus. I guess this is Nikon trying to hard to increase low-light focusing ability, and letting to much IR in to the AF module.
Don't spend to much time on it. Shoot something easily verifiable, and easily repeatable from a reasonable distance with reasonable light - if it doesn't work then, just send it in.
Repeatable: use a good, flat target, with depth cues visible in frame
Verifiable: shoot either from an armrest, or from tripod. You need several shots to get statistical reliability.
Reasonable distance: for the sake of [insert your deity here] don't shoot at makro distances. That's just stupid.
Reasonable light: Don't do it in multi-coloured stage light in the theatre. That's also just stupid...
This is a two-minute, two-cent cost solution: Use a folded piece of cardboard, and draw some high contrast marks on it. Put the folded cardboard on the ground/floor, and back off a bit. Works perfectly, costs nothing, and gives a several hundred times better real life correlation than the downloadable 45º A4 sized makro-targets you see all over the web.
Thank you Trench & Joakim. Appreciate your comments and will try to give this a try.
Joakim...I do have a tripod and can do what was suggested in the picture. A workable distance I guess would be about 10ft away or little closer? Once I have the target shooting, what exactly I am looking for in the picture? What would a GOOD case vs a BAD case scenario in the picture?
I can state that so far, I've had no trouble at all with my newly acquired Nikkor 50/1.8G AF-S on my D7000. I bought the 50 gently pre-owned in the FM marketplace (arrived yesterday, yeah for me!)
So far, it's TACK SHARP wide open at f/1.8 in less than stellar lighting. What a great lens it, and the 35/1.8G are. Liking my switch to Nikon better, and better with every click (shot Canon for years prior to this.)
And I'll chime in and state a big Thank You to "theSuede" as well. Nice, simple write up with a great illustration!
Anything between 5-10 feet is more than ok with a 35mm lens, concerning the AF measurements. Two feet is to close... Three is borderline. You don't need really big distances, unless you're testing longer lenses.
Things to look out for: Gravel is an excellent surface to put the board on. Grass and other really detailed surfaces are also good. The main thing is that it should be easy to see where the plane of focus is, and to do that you need surface detail.
The front of the board should be pointing as perfectly flat towards the camera as you can (within reasonable tolerances, doing it by "feel" is more than good enough if you just take some care). Then you point the center AF point somewhere down by the right corner of the board, take a shot. Defocus to infinity (just turn the focus manually) and AF back in, take a shot. Defocus to the front of the board manually, AF in, take another shot.
When you open the pictures in your computer, and zoom in on the board, the ideal scenario (at this general distance) is that the focused region should stretch out about as far behind as in front of the board surface. If the focus regions is mostly in front, but the board is still in acceptable focus, it's still frontfocusing. The board (and the point where the board touches the surface) should be the sharpest region in the image.
........
I've had no problems with my AF-S lenses, but I do know that problems exist. The important part is to remove "user error" from any possible explanation when talking with support personnel. And that you shouldn't doubt people saying that they HAVE got problems, but be very clear about what circumstances that are valid test scenarios.
trenchmonkey wrote:
AF fine tune tweaks are a slippery slope at best. If you're not shooting the lens with his D7K don't worry about it.
There are issues with D7K's, yet most NIB and refurbs are great upon opening...no adjustments necessary.
I have 4 bodys and 12 lenses and the only one that needed AF fine tune was the 135 f2 DC. Keep shooting and enjoy!
Glad to see your post Will,
Your absence from our pages had me thinking that you had decided to fix your roof and ...........
You need to get your cameras shooting and post some Sandies
