Tamron SP 15-30mm f/2.8 Di VC USD G2, calibrating with the Tap-In Console


After only four years on the market, the “old” Tamron 15-30 f/2.8 VC got replaced with the G2 version last autumn (2018). Not that the old version was performing badly by any means, but think about it, the legendary Nikkor 14-24 f/2.8 was released back in 2007 and there are still no rumors about a replacement or upgrade, but I guess Tamron was eager to get the full set of Holy Trinity of f/2.8 zooms out in “G2” style.

Anyway, at first look, the new 15-30 f/2.8 VC G2 lens looks like the same lens in new wrapping, as it has the same number of lens elements and groups. But it is clear that Tamron has done something more to this lens than just a new casing. The sharpness has improved, the vignetting is less, the Vibration Control has improved and the build quality is on the same high level as the other f/2.8 G2 lenses. And last but not least, it is compatible with the Tap In Console with the benefits that comes with it, like firmware update, focus limitation possibilities, VC behavior and focus fine tune at multiple points. Now, firmware update via the Tap In Console may not be a selling point for the Nikon F-mount, as I’ve hardly seen any update for the F-mount, but for the Canon EF and EF-S mount on the other hand, I’ve seen multiple firmware updates for the Tamron lenses. Why they need more updates for the Canon-mount than Nikon-mount to ensure compatibility when new cameras are being released, I don’t know.

Tamron 15-30 G2 0423_01

This is not meant to be a review of the lens in a traditional way, the intention is purely to see how the autofocus behaves. To help me determine the accuracy of the autofocus, I use a computer program called Focal from Reikan Technology. This program, among other features, takes a series of photos at different autofocus fine tune settings to determine at which setting the sharpness of the lens is at its best. Before the fine tune in camera and later multiple fine tune points in the lens, the optimum should be closest possible to zero at all apertures and focal length combinations. Obviously, this is extremely difficult, especially with a wide angle zoom lens.

Before continuing, it could be an idea to read some of the following articles as get a better understanding of autofocus in general and Reikan Focal.

Tamron SP 70-200mm f/2.8 Di VC USD G2, calibrating with the Tap-In Console
Tamron SP 24-70 f/2.8 VC USD G2, calibrating the lens with Tap-In Console
Tamron Tap-In Console, my experience
Why and how you should use AF fine tune in your Nikon DSLR

15-30 tapin

When I started to examine the focus of the lens, I used the new beta of Focal (2.9.5) and only after some time I realized that I couldn’t alter the aperture, as I couldn’t find the Preference settings, so I could only continue with max/largest aperture at all focal lengths. Being lazy I was thinking, this would be easy and fast, but then I realized that this wouldn’t be much useful or interesting if I don’t do the whole set of apertures as I’ve done earlier. So, I was thinking to publish with testing only at f/2.8 and redo the whole thing later, but then I was fooling around with the program and clicked on the “About” button just for fun and surprise, there was the “Preference settings” hiding. Hallo Reikan Technology? Why are you hiding one of the most important features of the program behind the “About” button? In the Preference you may alter many ways the program behaves, accuracy in the test procedure, what it should check before and under the procedure, jpeg or RAW, defocus away from or towards the camera, ISO, aperture, color temperature, exposure compensation and a lot more. I would say that this is so important that it should be among the tabs on top of the main window, not hiding it under “About”! I wasted a couple of days testing because of this. In the last final version, 2.6, the “Preference” settings have its own separate button on the main window where it belongs. When it was gone, I was thinking it’s not there yet because it’s a beta…. Update: the new final version has a “Settings” button on the main screen and from there you may find the “Preferences”. Good enough, thank you Reikan!

Enough of the ranting and over to the serious stuff.

15-30 G2 0.28 meter

So, at 28 cm we see that at f/2.8 the lens backfocus quite a bit at all focal lengths. This changes rapidly to frontfocus at f/4 and increases at f/5.6, and stays more or less the same at f/8. When seeing the whole result, the behavior is somewhat predictable, but the jump from pretty high numbers in plus at f/2.8 and rapidly into relatively high numbers in minus already at f/4 and more at f/5.6, makes it close to hopeless to calibrate at this focus distance.

15-30 G2 0.43 meter

At 43 cm we can see more similarities than differences to the results at 28 cm, it starts in medium plus and goes directly into minus at f/4. The upside is that it doesn’t go so far into the minus as at 28 cm, still though, big differences between f/2.8 and f/5.6.

15-30 G2 infinity

Finally at infinity things starts to calm down a bit and most runs ends up on the plus side of zero. I would like that as it doesn’t go far over to the minus side, the results could have been more balanced, mean more equal on both sides of zero.

Tamron 15-30 G2 0423_02

Equipment in use for the calibration:

Reikan FoCal 2 calibration software on my PC.
Reikan focus chart printed in highest quality on 120g non-glossy paper for close and medium distance, printed in A2 size for infinity.
Tamron Tap-In Console and Utility.
Nikon D750.
Tamron SP 15-30 f/2.8 Di VC USD G2.
Manfrotto 475B tripod.
Kirk BH-3 ball head.
2x Dynaphos soft-boxes with total about 450 watts of low energy lights for illumination of the focus chart.

NB, the values mentioned throughout this post is only valid for my lenses together with my camera, do not expect they will fit your lens and camera, they will most likely do it worse! So, do your own calibration and find your own values. I posted those values only to prove the point, not to give the final answer, and that is also why the Tap-In utility is shown empty.

Thanks for visiting!

Categories: GearTags: , , , , ,

11 comments

  1. Hi ,
    great post.. enlighten my understanding..
    so based from the result, how do you go about entering the calibration value via tape-in console?

    Thank you.

    Like

    • Hi Charlie and thanks for your question.

      As with all my posts about the calibration of lenses, I intentionally don’t show or tell how I’ve done it as I think this is an individual process. I think that all should calibrate their lenses according the expected usage. As an example, for nature photography you may prefer a small aperture, then I would emphasis to get most accurate auto focus at something like f/9. On the other hand I you like to photograph inside with poor lighting, I would calibrate best focus at f/2.8 or f/4. For more general use, one can argue to calibrate for f/4 and it will be pretty close at both f/2.8 and f/5.6. Hope this make sense?

      Ove

      PS, I’ve more or less finished writing a summary of the process of calibrating the Tamron Holy Trinity, but also this one won’t give away my final numbers. Not sure when it will be out though…

      Like

      • Thank you Ove.
        got it..

        i haven’t bought the Tamron 24-70 G2 yet, but had tried out FocalPro couple times with my current Prime Lenses (35mm DX / 50mm 1.4G)..

        so just wondering how i can go about picking a suitable value to calibrate the Tamron G2 with their Tap-in console without making a worse adjustment throughout the whole shooting range before purchasing..
        (after reading through reviews, i think the Tamron’s definitely need some tuning to bring the best out of it)

        so puzzling about the procedures ..
        does tuning results, let’s say with the middle focusing distance first, get ruined if i later fine tuned the different focal length at shorter focusing distance ..
        (since tap-in console has 3 distance specifically, short/mid/infinity)

        Like

      • Hi again.

        You need to check your lens at zero like I’ve done it the post and take it from there, your numbers will most likely differ from mine though. And after entering a value, you need to run the test again to confirm that you get what you want. If not, change to a new value and test again until you get the result you want. It’s a time consuming job.

        If you calibrate the lens at middle focus distance, and then do infinity and/or shortest later, I would recheck at middle also, just to confirm that it’s still good.

        Like

      • oh , one more question.
        for the range in this example..it said..0.43m ..is it 43cm away from the target? if using with FocalPro? (this is kind of close)

        if recall FocalPro has some suggested distance with their A4 printed target ..

        Like

      • Hi.

        If it says 43cm then that’s the distance the camera and lens think it is the distance to the target. What you measure or what Focal shows doesn’t matter. Take a photo and use a exif reader to find the focus distance the camera and lens are using, you may repeat several times before you get the right distance.

        Reikan Focal are mainly made for calibrating Nikon and Canon cameras with their 1st party lenses, who should be calibrated at somewhat medium focus distance only. Calibrating at 15mm with the lens almost touching the target is stretching the ability to the program and you may get some error messages in the process. The same can be said while calibrating at infinity….

        Like

      • Got it, thank you so much^^

        I just sold my d7200 for an z6 this week ..
        i’ll try out the focus method mentioned by you ..

        meanwhile .. this mirrorless new device really amazed me by the focus result 😛

        i will try out the tokina 11-20mm i have in hand first ..
        (haven’t get Tamron 24-70 g2 yet)

        Like

      • Hi.

        Enjoy your new toy. If you haven’t, it could be interesting to read the blogpost about the Z6/Z7 from Reikan: https://blog.reikanfocal.com/2019/05/nikon-z6-z7-vr-analysis-with-reikan-focal/

        Like

    • hmm
      sorry , still a bit confused,

      i loaded up a test shot done with FocalPro..
      so based from the software’s target preparation suggestion tool, i set up my camera @ about 2.6m away from the target ..
      perform the needed test throughout the guided procedures..

      as for the Tamron Tap-in Console in this article’s example, on the target distance, the middle range is showing 0.43m (for your example lens)..

      so wondering what parameter i need to look up at the exif meta info?
      distance to subject is showing 2.6m ..
      the closest similar value field i saw is the DOF value, which is showing something like 0.## m

      Like

      • About confusion, welcome to the club!

        As touched into in the last reply, Focal is mainly made for medium focus distance with first party lenses and to use this program together with Tamron (or Sigma) we have to bend the rules a bit and ignore some of the guide lines in the program and set up according to what we need. So in this case you should move your camera until you get 0.43 meters (or as close as you can get), and ignore the error message or suggestions from Focal. I normally turn of target confirmation in the settings for this very reason. When you’ve found the right position of the camera, you should obviously not move it before the whole test run at that focus distance is done.

        I don’t know what camera you are using, but for me using Nikon together with a small free program called “Picture Information Extractor” from https://www.picmeta.com/ When I click on a thumb nail of a photo in that program, all exif information are available on the right side and somewhere far down there is “Focus Distance” written with a number behind. This is the number I’m using to decide how far away I should position the camera from the target for the test. Other program and Canon may have other naming, but in general you should look for something like focus distance or similar. After months of struggle, I found this value to be the one that gave me most predictable and repeatable test runs. I’ve written more about this in the upcoming article.

        Like

  2. thank you 🙂

    so basically i’ll just need to play around with all the settings for the best acceptable result ..
    no short cuts to save some time XD

    now i’ll wait for mid-night discount to place order on the G2..

    thanks again~ looking forward to reading more posts from you~

    Like

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