Auto Focus fine tuning and Santa

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Had a pretty good Christmas this last year. Santa got me a couple of new toys and I’m anxious to go play. Added a couple lenses to the bag. Just received this week a new Tamron 70-200mm f/2.8 DI VC G2 and the Tamron 17-35mm f/2.8-4 Di OSD. I know what some of you are thinking, why not get the Nikon 70-200mm f/2.8? Yeah, I guess I wasn’t that good of a boy this year and the Nikon was still out of budget range. I’m hoping the image quality stands up. And to that end it brings me to a few questions I have that I hope some of you are willing to comment on.

Nikon D800E is my primary camera, but also now have a D7100.

  1. When you get a new camera or lens, what testing rigors do you go through to make sure the quality is as good as you expect it to be? Do you do any sets of test images with resolution charts or images from the field and then analyze them? Or do you just take it out of the box and start shooting? Or something in between?

  2. Does anyone go through the Fine Tuning of their Auto Focus system? either from the camera perspective and/or the lens? Starting to google and watch some videos, but would sure like to hear anyone’s experience on whether or not this is something worth spending time on. As some of you might know, I’m relatively new to the digital world and dslr’s, only for 3 years now, where most of you have been shooting digital for 10 or more years.

  3. As a subset to #2, Tamron has the TAP-in Console. Anyone have any experience fine tuning AF with that? I’ve already used it to update current firmware, so that’s pretty cool.

Any comments along these lines regarding fine tuning the camera/lens pair will be appreciated. What do you do? Any links, resources, experiences you can share appreciated.

Oh, and I might as well ask if anyone has or has owned either of these lenses and your opinion of them.

Thanks in advance!

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Lon, as you and I talked about your new lenses off line recently I caught this post and only wanted to make a comment on this question quoted above here. As you’re aware I only use all manual gear. But oddly in my poking around on Youtube I came across a few different folks who seem to have some very interesting testing procedures for AF on various products. Although it’s been quite awhile now at the time they seem to even make sense to an old manual gear guy like me. Looking forward to seeing some takes with the new lenses at some point…:cowboy_hat_face:

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Congrats! Since I don’t use autofocus except on a rare occasion, I don’t worry about the fine tuning. I do use my back wood fence (grain really shows) as a test grid and shoot a new lens at various lengths and f-stops and pixel peep at 100%. It will tell you a LOT about your image quality.

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I hate to admit it,but I generally just go out ans shoot and if I don’t like the results, I start looking deeper. That said, I’ve only had one lens that I just couldn’t get along with; most have worked superbly out of the box.

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Thanks for the responses guys.

@Harley_Goldman I wanted to ask you to expand on “manual focusing.” I know it sounds silly and it should be obvious. However, I think there could be different definitions and methods of manually focusing. Does manual focus mean you’re simply using the focus ring with AF turned off - but you’re still relying on the green dot in viewfinder? OR are you deciding the image is in focus by literally looking in the viewfinder and watching the image go in and out of focus (much like we did with LF?) OR are you manually using Live View to manually focus?

I only mention this because I’ve been reading and learning. Maybe everyone knows this and I didn’t - If so, please indulge me. There are TWO different focus systems (at least in Nikon, can’t speak to others.) Looking through the viewfinder you’re using the Phase Detection focusing system which is NOT, NOT the same focusing as using Live View (LV). In LV, the mirror is UP and the focus in directly measured on the sensor! This is called Contrast detection focusing When you focus in the viewfinder, regardless if you’re using the green dot to confirm focus, or the naked eye - you’re not seeing and focusing what the sensor sees!!(at least real time). There is a separate sensor/system/firmware whatever that is processing and presenting what the camera thinks is in focus.

When in manual, even though the cameras are all digital… are we still seeing an analogue view in the viewfinder? ie. the image comes through the glass of the lens, bounces off the mirror and directly out the viewfinder/eyepiece? If that’s true and those mechanics are still all manual and analog, then I can see the value of focusing manually.

If there is any interruption in the image details between the lens and the eyepiece (sensors, digitization, etc.), even though you’re in manual mode, you’re still relying on digital electronics to view the image in the viewfinder.

Anyway, back to Live View. I found out through experimenting and then confirmed online by reading, that indeed Live View and the Viewfinder have two different focusing systems. And to that point, the AF Fine Tune process I was originally asking about DOES NOT apply or work when using LV. It only works for Phase Detection focusing. I confirmed that as I performed a bunch of test images using Live View and turning on AF Fine Tune. I took dozens of shots changing the AF Fine Tune settings each time and the results were there wasn’t any differences in any of the images despite changing the settings! This had be scratching my head, but then made perfect sense after I learned that AF Fine Tune has no impact using Live View.

Further comparisons between LV and VF (Live View, Viewfinder) brought very revealing results. So far, it’s pretty clear that the focusing using LV provides the best sharpness. Even after fine tuning to death using VF.

This is a huge deal for most any other type of photography besides Landscape, maybe architecture. Wedding photographers, street, sports, journalists, etc. rely on the viewfinder almost exclusively right? Therefore AF Fine tuning is probably pretty important to maximize focusing and sharpness for a particular lens/camera combination.

In landscape photography not as much. Although there are reasons why folks might not use LV - battery usage for one main reason.

This whole process so far has also helped me confirm why I’ve been seeing such good results in terms of sharpness and detail when I do focus stacking. I use Live View to focus!.

Well, I’m finding this all very interesting and educational. Maybe you all already knew this… :roll_eyes:

Now it’s time to go finish putting the lenses to more testing. Thanks for listening.

If I get a chance I’ll post some pics

Lon

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I am doing these two things. I mostly focus in the viewfinder but on occasion, if I need a very specific spot or if the light is dim, I will use LV but manually focus. I only autofocus if the light is so dim I really can’t see to focus. I am an old school dino! :slight_smile:

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