Nikon D3200 lens Calibration
This post is about how you can perform a D3200 lens calibration. A little while back I bought a Nikon D3200 as a lightweight alternative for my ‘professional’ gear when I wanted good quality, but didn’t want to be weighed down with my ‘professional’ gear. While it’s a great little affordable camera one of the things it is missing is the AF Fine Tune function found on my higher spec cameras. This led to a lot of belief on the Internet that it’s not possible to do a D3200 lens calibration which is untrue, you can!
However, you have to do this by mechanically calibrating your camera to your lens, and not by using software to calibrate your lens to your camera. Fear not, it’s a lot easier to do a mechanical D3200 lens calibration than it sounds and you don’t need to disassemble your D3200 to do it. All you need is a 2mm Allen Key, or hex wrench as I think our American cousins call it. The only mechanical skills you need is the ability to turn an Allen key by a few degrees and a fairly steady hand.
Credit is due and given to Leon Goodman who wrote the article that showed me how it was possible to do this calibration and you can view his much more complete article here. I chose to write this blog post not to highlight anything Leon had missed, but to simplify Leon’s much more in-depth and technical article in the hope of inspiring others who like me originally thought is sounded all a bit too complicated to try at home!
Lens Calibration or Camera Calibration?
Before you start its important to realise we are actually talking about D3200 camera calibration here and not D3200 lens calibration. This process describes how to calibrate a camera to a single lens, it’s a global adjustment that will affect all lenses. The AF Fine Tune function found on other cameras that the D3200 lacks is lens specific so you can adjust each lens individually to your camera. Here we are going about it the other way, calibrating a camera to a lens. However a lot of D3200 users will only have a single lens or a few lenses and so this is potentially still a useful fix.
Because the adjustment calibrates the camera to the lens I would use this method with either:
- The lens you use most often to maximise sharpness on that lens
- The lens that gives you the most unacceptable results
In my case the kit lens, having a maximum aperture of F4.5 wasn’t too bad, on my Nikon 50mm F1.8g however when wide open it showed enough front focus as to make it annoying at wider apertures. Remember the higher the ‘F’ number, the greater the depth of focus and so the more tolerant it is of a slight misalignment in focusing. With fast primes when used wide open the depth of field can become so shallow that any focus alignment issue becomes obvious, particularly at longer focal lengths.
The calibration process itself is really simple, you need:
- A 2mm Allen Key (or hex wrench)
- A small torch or enough light to see into your camera housing
- A focus target, I used a row of batteries, set up diagonally to help me see if focus is to front or rear.
- Ideally a tripod
D3200 Camera Calibration Method
Before we begin here is the disclaimer, you are on your own here, do at your own risk, I accept no liability! This post does not represent professional advice, just explains the process of how I solved my own cameras focus issues.
The basic process is:
- Calibrate your dioptre
- Establish if your D3200 has back focus or front focus issues when focusing manually
- Adjust and re-test
- Establish if your D3200 has back focus or front focus issues when focusing using AF
- Adjust and re-test
- Check other lenses are acceptable
Nikon D3200 Camera Calibration Steps in Detail
Here are the steps to follow in detail.
Calibrate Your dioptre
The dioptre provides ‘Eye Relief’, essentially its like a pair of glasses for your eyes and helps your eyes focus on the internal viewfinder image. The first step is to adjust the dioptre on your D3200 to give you the clearest possible view your eyes are capable of. To do that mount on a tripod and switch on live view, use the screen gauge sharpness and manually focus on the centre target.
You need a target to shoot at that will show front or rear focus and there are various lens calibration targets out there, plus commercial products available to aid you. Personally I just lined up a load of C cell batteries diagonally in front of the camera at eye level with the those on the left further away and those on the right nearer. The commercial products will show you more accurately how out of alignment you are, but remember without software based micro adjustments it’s a bit overkill on the D3200. Shoot the one in the middle and if one to the left is more in focus you have a back focus issue and if one to the right is more in focus you have a front focus issue.
It is important to focus using the live view because what is displayed on the screen is a true representation of what the sensor sees and is independent of the mirror and viewfinder.
Take a test shot and you should find it is as sharp as your camera and lens is capable of.
Without moving the camera or touching the focus, adjust the dioptre by the viewfinder so that the image you see through the viewfinder is as sharp as possible. You have now calibrated your dioptre!
D3200 Mirror Calibration for Manual Focus
Having a calibrated dioptre on its own only solves half the problem if your mirror is not calibrated. If this is the case you need to get it sorted before look at your auto focus otherwise you will never have any visual confirmation through the viewfinder of what is in focus or not.
This is the trickiest bit, but it’s not rocket science. It is basically a case of while on the tripod, manually focusing on your target and then judging visually if the battery in the centre, or one to the left or right is the sharpest in focus.
Original problem, camera is clearly focusing in front, F2.2
Oops, overdid it! I turned the wrench too much and now I have a back focus issue. F2.5
About right, maybe not perfect but dam near spot on. This is actually auto focus at F2!
The key thing to remember here is you can’t judge based on one shot. You need to take a series, 3 to 6 at say F2.8 or above, remembering to focus on infinity each time before manually focusing. Make your judgement based on the average. Only adjust if consistently front or back focusing.
If you establish that you have a front focus or back focus issue, it is simply a case of making the proper adjustment then repeating until you are satisfied that the manual focus is as close to spot on as you can get it.
The adjustment bit is easy. Use the feature ‘Mirror lockup for Cleaning’ and then with the mirror locked up, remove your lens and looking into the lens housing, note the two Allen bolts and take your 2mm Allen key and insert it into the Allen bolt furthest away from the sensor, nearest outside of the camera housing. Note its position before starting and then turn the Allen key slowly, a small turn affects things a lot, start off with about 10 degrees to the left or right and make a note of which way you went.
Use the ‘Lock Mirror Up For Cleaning’ function before taking the lens off.
The ‘Mechanical bit’ – easy, just two Allen keys, one for manual focus and one for auto focus!
Take key out, attach lens and test again, noting if the focus is better or worse. If worse, turn the allen bolt the opposite way, if better, keep going until you are satisfied. You have now calibrated your mirror!
D3200 AF Calibration for Auto Focus
You now need to follow the same process to calibrate your auto focus (AF).
Switch to auto focus mode using the option to use a single focus sensor in the middle and single focus (AF-S) not continuous focus (AF-C).
Take a series of test shots to prove if you have a front focus or back focus issue or not.
If you do prove there is an issue, lock the mirror up again use the mirror lockup function then remove the lens and this time use your 2mm Allen key to adjust the Allen bolt nearest the sensor. Take care here not to touch the sensor.
As before, re-test and check. If worse, go the other way and if better, keep going until you are satisfied.
You have now calibrated your AF to match your lens!
Check Other Lenses
Check your other lenses you use with the camera and make sure you are satisfied. Remember this change is global across all lenses and so a lens that was already perfectly aligned may show signs of not being aligned after you have calibrated your camera for another lens.
In my case all the lenses I use with my D3200 showed an improvement to the point I would happily shoot at F2 on my primes with no worries about sharpness at all.
So there you have it, a little guide to how to mechanically calibrate your Nikon D3200 to a lens. I hope its been useful and you get as much of an improvement as I did with when I calibrated mine as its given me a lot more faith and enjoyment from my little lightweight setup.