Darren01 Loc: Fallbrook California

I have a Canon 80D and there is a new firmware update for it. My question is - if I update the firmware will it erase all the lens calibration I have done for all my lenses? I'm assuming it probably will but am not sure. That would be a pain to have to re do all that. Thanks for your replies, Darren01
Currently running version 1.0.2
New version is 1.0.3

CHG_CANON Loc: the Windy City

No, it should not impact focus fine-tuning. People wouldn't update their firmware otherwise and the new capabilities and fixes would go unrealized.

Darren01 Loc: Fallbrook California

Thank you CHG_CANON. I will commence !

Darren01 Loc: Fallbrook California

It was more or less a WI-FI security update when connected to a computer on an unsecure network. Doubt it added any noticeable functionality updates. I don't use the Wi-Fi anyway....
went without a hitch.

CHG_CANON Loc: the Windy City

Much ado about nothing ...

Darren01 Loc: Fallbrook California

TriX Loc: Raleigh, NC

On principal though, it wouldn’t hurt to write down the calibration settings. Not only if they are inadvertently lost, but for comparison to future calibrations of the same lense(s) or when you change bodies. If you use the FoCal system, you can save a complete report of each lens test in a folder of your choice. When I recaled all my lenses after changing from a 5D3 to a 5D4, I found it very interesting (at least to me) to compare.

travisdeland Loc: deland, FL

that's a very good point you make. Keeping a record of the calibrations helped me to spot a problem developing with a lens, as the adjustment kept changing, when all others didn't. Was able to send the lens to canon for repair, at my convenience, rather than have a failure in the field. I wasn't using FoCal, just the in-body adjustments.

linvilleDave Loc: Linville, N. C.

Newby question, please be kind. I have a Sigma 18-75 which I use most of the time. Can, and should this be calibrated? If so, How? Thanks.

CHG_CANON Loc: the Windy City

It depends on the model of camera as well as a question of why?

Don, the 2nd son Loc: Crowded Florida

Always good to check for what this update will do for me!! Many don't do a thing I'm interested in.

linvilleDave Loc: Linville, N. C.

Chg Canon, Canon T6s. I've notice latley pics are a little out of focus. Haven't used it since my wife of 49 years passed.

CHG_CANON Loc: the Windy City

A T6 doesn't offer a tuning feature. Try some rubbing alcohol on a q-tip on all the metal contacts for the camera and lens as the first step. If that doesn't seem to help, create a new thread and post some JPEGs straight from the camera, storing the originals, and ask people to take a look.

amfoto1 Loc: San Jose, Calif. USA

Chg_Canon is correct. What's being discussed here is called "Micro Focus Adjustment", a feature that allows the user to fine tune the focus accuracy of up to 40 different lenses on their particular camera.

However, your T6i doesn't have the Micro Focus Adjustment feature that's found on some other Canon DSLRs. None of the "Rebel" series have it. The 50D was the first APS-C Canon model to have MFA (a simpler, 20 lens version). For some reason Canon left it off the 60D. But it's available in 70D, 80D, 90D and both the 7D models.

If your lens & T6i need focus calibration, it would have to be adjusted by a professional camera repairer.

First try to determine if there actually is a calibration problem.... Eliminate all other possibilities before having it adjusted.

Be sure you fully understand how the AF system of the camera & lens works and that you're using it correctly (I'd guess that 8 or 9 out of 10 "focus problems" are user error... no fault of the camera and lens). The most accurate way to auto focus on a stationary subject with your camera's viewfinder-based focusing system is using a single AF point, manually selected, using One Shot focus mode. For moving subjects, you must switch to AI Servo mode, which provides continuous focus.

AI Focus isn't really a focus mode at all. With it, the camera is supposed to decide whether the subject is moving or not, then switch to use either One Shot or AI Servo, as appropriate. It is generally better to NOT use AI Focus and to make those decisions yourself in advance.

AI Servo can be used all the time, with both stationary and moving subjects... IF a technique called Back Button Focusing is also used. Search for info on that, if interested.

Some of the camera's shooting modes, set with the big dial on the top shoulder, will not allow you to use some of the above focusing modes. For example, full "Auto+" (the "green box") forces you to use AI Focus and All Points, taking away most focus control from you and letting the camera make all the decisions where to focus. The "SCN" modes also probably decide a focus mode... For example, "Running Man/Sports" icon probably will only use AI Servo.

Your best bet to take control of the AF system is what Canon calls the "creative zone" exposure modes: Av, Tv, P and M. Those are ONLY exposure modes and leave all AF decisions, settings and control up to you.

Next, you can test your lens for focus accuracy. First remove any filters from the lens. Use the lens hood to keep out oblique light that might "mess with" focus. Be sure the lens and camera electronic contacts are clean and working properly.

The AF array you see in the viewfinder is a fast "phase detection" system, which is what would be adjusted, if necessary. Each AF point in the array is actually two sensors, which are supposed to focus the image on the camera's image sensor when the two images are aligned. Your DSLR actually has a second, completely separate focusing system in Live View (and video) mode. This system uses the image sensor itself to focus, so it requires no calibration.

You can test the viewfinder/phase detection array's accuracy against the sensor-based Live View focus to see if there's a significant discrepancy. Simply set up the lens and camera on a tripod, aimed at a flat, detailed, well lit target (like a weathered fence or a brick wall)... as parallel as possible with the camera's sensor. Focus using the center point only of the viewfinder AF system... then, without moving anything, switch to Live View and focus again using the sensor-based AF system, while watching to see if the lens focus ring moves at all. If it does, there's a discrepancy between the two focus systems. If it's only a very slight movement, a small discrepancy between the two AF systems, it's probably nothing to worry about. With all but the largest aperture lenses Depth of Field will cover minor focus errors.

Another way to test is to set up a target on a diagonal... such as a row of batteries or a ruler. Next mark and focus on one particular point and take a shot, using the largest possible lens aperture (shallowest possible Depth of Field). Inspect the image to see if the sharpest area is centered on the point of focus... or if the lens is front or back focusing a little, suggesting it might need calibration.

There are available special focus test targets that serve the same purpose as the above batteries or ruler homemade target. For example: https://www.bhphotovideo.com/c/product/970599-REG/lensalign_la_la2_mkii_focus_calibration_system.html/?ap=y&ap=y&smp=y&smp=y&lsft=BI%3A514&gclid=Cj0KCQiAtf_tBRDtARIsAIbAKe1HvjJIbkI1lDxt6gtAmKNsk2Q_pnBEWEZkCo4rW2I4xE6tThQat2saAvwfEALw_wcB

The problem with these focus tests occurs when they're used near the lens' closest focus distance, when they aren't testing focus accuracy at more "normal" shooting distances. A more advanced and automated system such as Reikan FoCal uses a target that's typically set up a lot farther away (50X lens focal length recommended, 25X okay with telephotos). But, because your camera doesn't have MFA, FoCal isn't an option for you. In fact, all this testing would only highlight a problem... it gives you no means of correcting it.

Zoom lenses such as yours also present additional challenges to test and calibrate. The focus may be different at the two extremes of the zoom range... and even different again at settings in the middle. The more recent Canon camera MFA system allows up to two adjustments with a zoom lens.

linvilleDave Loc: Linville, N. C.

Thanks everyone. Gotta get my mind back on the camera, and get going again. Again, thanks.