I had the first model of the Tamron (1st month they were out.) used with a 7DII & 6D. The 7DII and the Tamron did not play well together either. But my 6D and the Tamron worked so well it was as if Tamron used a 6D to design the lens.
As per a phone call I sent the lens to Tamron and they did the firmware updates(2) and adjusted the lens to work with a 7DII. The same day I got the lens back Canon also released a firmware update for the 7DII that addressed the problem.
My G2 has never had problems with any of my family's bodies (6 different Canons-5 aps-c and 1 FF). Though the 90D with 32MP packed into an aps-c sensor is EXTREMELY sensitive to motion blur, esp. out at 600mm.

I performed focus tests with all of my EF mount lenses with my R5 mirrorless using a focusing chart on a 45-degree angle. The focus for every Canon lens was spot-on, including the 100-400mm II with 1.4x III that I had to micro-adjust significantly for my old 7D II. No surprises with the Canon lenses.

However, in testing the Tamron 150-600mm G2 lens, the focus was way off. Focus was 1-2 inches nearer than the intended focus point. Completely unusable on the R5 as-is. The lens when mounted on my 90D crop sensor is pretty good at the focus point, but I can see it stays in focus all the way down the chart 1-2” closer to the camera, therefore it also has some front focusing issues, just not as bad.

For those of you who have the Tap-in console and have used it, does it do a good job in correcting this front focusing problem? I don’t have the Tap-in console, and am wondering if it is worth the $59 to purchase at this point.

I’m a little on the fence whether to stay with the Tamron or not. The wide focal range in one lens is great for wildlife. Note that I do have the RF 800mm f/11 on order which will extend my focal range even on the R5 with full frame sensor, but in a fixed focal length. My intent was to use the crop sensor DSLR with the long telephoto zooms for wildlife for a while, and the R5 with shorter lenses for everything else. With the R5’s animal eye focus, that may change my strategy. I just don’t know how well a focus tuned Tamron would work with it.

And, then there’s the rumored R7 mirrorless crop sensor body that may be released soon!

Thanks for the info. I purchased the Tamron G2 because I wasn't getting consistent sharp photos from the Canon 100-400 and 1.4x on my 7D II even after micro focusing them together. Now with the 90D and R5 bodies, the Canon 100-400 / 1.4x combo is giving very sharp results on both. I did update firmware on both camera bodies and the Canon 100-400. Being an IT professional, I should know to update the firmware as first course of action - Duh.

I'm not sure the extra 40mm and 2/3 f-stop of the Tamron is worth the bother of fixing the tuning. I purchased the G2 as a rental from Lens Rentals at a very good price. B&H used dept is offering almost as much as I paid for it, and I'll keep the $120 B+H filter that came with the rental. I'm anxiously awaiting the Canon RF 800mm to ship from B&H once it's back in stock.

I also owned the first and now mk2 of the Canon 100-400L and used both with the 1.4x III. I got great results. My G2 stays on a tripod, usually with an 80D attached. The 100-400L is my hand held from a blind or walking in the park lens. After a year of lock down for Covid-19 what little exercise I got disappeared and the 100-400 is getting a bit heavy (I am 75 and LAZY) so I went on Ebay and found a 70-300L with Kenko's Canon dedicated 1.4x for sale by a pro photographer in Florida who is going to the R/RF world. I will now be giving that a try, esp from a blind close to the birds. I have a ton of tripods & monopods so I ordered an inexpensive Chinese knock off of a high end gimbal head to use with the 100-400 out and about (if that becomes a thing again). And if I can get over my aversion to carrying a tripod or using a monopod. I guess I could clean the patio and unbury the home gym and use it, likewise the tread mill in the family room. It makes such a great rack to hang stuff on. But the main problem will be the LAZY and the fact that treadmills and gym stuff bore me to tears and creative cussing.

I performed focus tests with all of my EF mount lenses with my R5 mirrorless using a focusing chart on a 45-degree angle. The focus for every Canon lens was spot-on, including the 100-400mm II with 1.4x III that I had to micro-adjust significantly for my old 7D II. No surprises with the Canon lenses.

However, in testing the Tamron 150-600mm G2 lens, the focus was way off. Focus was 1-2 inches nearer than the intended focus point. Completely unusable on the R5 as-is. The lens when mounted on my 90D crop sensor is pretty good at the focus point, but I can see it stays in focus all the way down the chart 1-2” closer to the camera, therefore it also has some front focusing issues, just not as bad.

For those of you who have the Tap-in console and have used it, does it do a good job in correcting this front focusing problem? I don’t have the Tap-in console, and am wondering if it is worth the $59 to purchase at this point.

I’m a little on the fence whether to stay with the Tamron or not. The wide focal range in one lens is great for wildlife. Note that I do have the RF 800mm f/11 on order which will extend my focal range even on the R5 with full frame sensor, but in a fixed focal length. My intent was to use the crop sensor DSLR with the long telephoto zooms for wildlife for a while, and the R5 with shorter lenses for everything else. With the R5’s animal eye focus, that may change my strategy. I just don’t know how well a focus tuned Tamron would work with it.

And, then there’s the rumored R7 mirrorless crop sensor body that may be released soon!

The Canon EF mount Tamron 150-600 G2 (A022) has known problems focusing when used on R5 (and other R-series) via an EF to RF adapter. If I recall correctly, the most noticeable thing is that the lens is not as fast as it was on Canon DSLRs. Probably you are seeing "missed focus" because the shutter is releasing before the lens has completed focusing. According to Tamron's support website, 150-600 C2 lenses serial #040336 and later should already have the Ver.2 software installed. Serial #'s prior to that will need the firmware update to work properly on the R-series cameras.

Tamron 150-600 G2 for Canon firmware Ver.2 is said to help lens performance on the R-series cameras. You either need to use the Tap In module to install the firmware yourself or send the lens to Tamron to have it done.

Info about the firmware update can be found here: https://www.the-digital-picture.com/News/Default.aspx?Cat=Tamron-Firmware-Updates

Info about using the Tap In module is here: https://www.the-digital-picture.com/Reviews/Tamron-TAP-in-Console.aspx

No "calibration" should ever be needed with any lens on any mirrorless camera that has AF sensors embedded in their imaging sensors, as all R-series and, for that matter, all or most mirrorless now do. Because the mirrorless camera doesn't have light being redirected by a mirror to a separate array of AF sensors the way DSLRs do, there's nothing to calibrate. (Live View focusing in DSLRs that uses the image sensor itself or similarly embedded AF sensors to focus also does not need calibration... but in DSLRs this is only for their Live View focus mode.)

Hi MtManMD,

Just curious if you ever resolved this issue. I am currently in the middle of renting the Tamron 150-600mm G2 lens for use on my EOS RP and am experiencing the focusing issues mentioned in this thread. I decided to rent before buying because I'd read about these same issues. The serial number on the rental lens is 012xxx, so it's an early production unit and the local company I'm renting from may not have updated the firmware.

Thanks in advance for any info you can provide.