Metis407 Loc: Canada

I believe that my 18 to 400 Tamron lens autofocus is out of whack. I have been looking at calibration. Does anyone have expetience of this? It looks somewhat complicated and labourious!! I think I could do it, but dont want to mess it up!!!

CHG_CANON Loc: the Windy City

Might want to consider posting an example for others to assess and confirm the lens rather than technique. You might too want contact Tamron if the lens is in warranty. Also, is the firmware on the camera up to date?

LFingar Loc: Claverack, NY

If you do decide to do your own focus calibration then this might help:
http://regex.info/blog/photo-tech/focus-chart

mwsilvers Loc: Central New Jersey

Can you be more specific about "out of wack"? As suggested, post a hi resolution image with store original selected so we can get a sense of the problem. You don't indicate a manufacturer or model of camera you are using it with. A description of exactly where or how you believe it's out of focus will be very helpful. While calibration may help, it's always possible you have a defective lens or your expectation for sharpness in a moderate priced superzoom lens is too high, or your technique at say 400mm may need to be developed. In any case without knowing exactly which camera you are using, and a better understanding of the issue, our experience calibrating lenses may not be very helpful to you.

Metis407 Loc: Canada

Thank you all for your replies.
I have a Canon 77D. I have been trying to take photos of a test card first manual focus and then AF. To be candid I find it hard to tell the difference. However where I have problems is at the 400 mark, say taking a flying bird. Which I guess would suggest a technique flaw rather than a lens flaw.The Bird just seems a touch out of focus.I would add a photo if I could see where!!!

ChristianHJensen

I just calibrated one of these and it does take some time to do it right. I use the FoCal software as it makes the process a bit less painful. You will need targets in multiple sizes to do a full range calibration - 3 different distances for 18, 35, 50, 70, 100, 200, 300, and 400mm. In all 24 calibration values that can then be programmed into the lens with a Tap-in console as the camera itself can only contain one AF cal value which is far from enough on such a wide range lens. I got values for mine that range from -17 to +12 depending on zoom level and distance.

It is well worth doing - but some effort involved. You will need several different focus targets (size) and a strong light source to do it right

mwsilvers Loc: Central New Jersey

If your lens needs calibration it should be obvious with static subjects. Moving subjects add a whole separate level of complexity. Shooting a BIF at 400 millimeters hand held can be difficult and takes both developed skill on the part of the photographer, a camera autofocus system that is up to the task with the correct AF area options selected, and a shutter speed of at least 1/1000 of a second. What was the shutter speed you used? Which autofocusing area selection mode did you use? Were you also using AI Servo? Were you shooting in Av, Tv, or M modes? Camera set up is critical. Additionally it is likely that an inexpensive lens like yours will be tack sharp at 400mm even for static subjects although you may get quite acceptable results.

You can attach photos clicking on the "choose file" button. You are then directed to select a jpeg file off your hard drive. I believe it should be smaller than 20 megabytes in size. Once chosen you should see the file name selected in UHH below the Send/Preview buttons. Next click the "store original" box and then the "Add Attachment" button. After a delay you will see your attached picture with the word Download under it. Then simply press the Send button.

Metis407 Loc: Canada

FoCal Plus or Pro? Thanks

Metis407 Loc: Canada

at 400mm F22 and 1/500

(Download)

Metis407 Loc: Canada

use centre focus mode

Metis407 Loc: Canada

AI servo and AV mode
Sorry keep adding answers to your questions!!

ChristianHJensen

I use the Pro version

Metis407 Loc: Canada

Not sure FoCal works with Canon 77D, have emailed them to check..

mwsilvers Loc: Central New Jersey

Shutter speed at 1/500 is too slow and the f/22 aperture may be causing diffraction. You could have easy used a shutter at 1/1000 an aperture of f/8 and an ISO of 400, instead of 1/500, f22 and ISO 1600, and gotten the same exposure for an image like this. You don't need that much depth of field to capture a bird in flight. Was there a reason you used f/22? To quote the British website Amateur Photographer's review of your lens, "Our Image Engineering Tests tell us the lens is at its sharpest when it’s used at the wide end of the zoom and gets progressively less sharp as you zoom in. For the sharpest results at 18mm you’ll want to use the lens around f/5.6, whereas at 70mm you’ll want to close down to f/8 to see an improvement in corner sharpness. The level of sharpness drops off quite noticeably when you push towards 400mm, with diffraction visibly softening images throughout the focal range from f/16 onwards."

https://www.amateurphotographer.co.uk/reviews/lenses/tamron-18-400mm-f3-5-6-3-di-ii-vc-hld-review/6

There may be other issues including which AF shooting area you used and your shooting technique at 400mm, but the shutter speed and aperture are places to start. Its hard to say whether calibration will do the trick because everything is very soft. Calibration fixes front focusing or back focusing issues. and adjusts the focus plane. While the surf behind the bird may be a bit sharper there is nothing that shouts out calibration to me in this image. And as I've said earlier a lens like this has some limitations at 400mm especially if hand held, so there could be multiple factors affecting this image..

Metis407 Loc: Canada

Thanks, will try shutter speed priority and reduce aperture. use centre AF servo, and I guess a lot more practice!!
Thanks again good advice...