In our group there are 4 of us with the Tamron and one with the Sigma 150-600- (Nikon & Canon) and the real trick for most of us (In our 70'sexcept for 1) is using a Monopod or hand holding. 3 have full frame and I have a Canon 7D MK II which as stated earlier is about a 960mm lens. I'm 77 and not the strongest guy in the world! - I can hand hold it but I do bump the ISO up as needed and with my camera the noise is not bad at all- I can shoot at 3200 ISO with very little noise. The Canon 5D MK III also is quite good on noise along with the Nikon 810. We all cannot believe how sharp these lenses are!! Two of us have Gimbal heads and have never used them!!! I have used a monopod with some success but find it gets in the way at times. I still prefer hand held!! I thought the weight would be a real no no for me but have learned to use it!! And Love it!

In our group there are 4 of us with the Tamron and one with the Sigma 150-600- (Nikon & Canon) and the real trick for most of us (In our 70'sexcept for 1) is using a Monopod or hand holding. 3 have full frame and I have a Canon 7D MK II which as stated earlier is about a 960mm lens. I'm 77 and not the strongest guy in the world! - I can hand hold it but I do bump the ISO up as needed and with my camera the noise is not bad at all- I can shoot at 3200 ISO with very little noise. The Canon 5D MK III also is quite good on noise along with the Nikon 810. We all cannot believe how sharp these lenses are!! Two of us have Gimbal heads and have never used them!!! I have used a monopod with some success but find it gets in the way at times. I still prefer hand held!! I thought the weight would be a real no no for me but have learned to use it!! And Love it!

I have the Tamron 150-600 and I have a real love hate relationship with the thing.

I've become addicted to that long reach and find myself photographing birds more than any other subject these days.

Using a lens that performs best at f/8 in early morning light on skittish subjects means that you are going to have to get used to ISO 3200 and even 6400.

While it is possible to get decent images at these ISOs there is absolutely no question that you lose some of the fine feather or fur detail that can make a really high quality wildlife image so satisfying.. The combination of high ISO and low light just makes for noisier images.
I use my Tamron mostly with the Canon 7DII and I've simply had to get used to a higher level of noise than I was seeing from my 6D. There are those on this forum that will tell you that they get excellent images on a crop sensor body at 12800 ISO and as my eyes continue to age I may agree with them.

Good noise reduction software helps as does a full frame camera but.......if you use a FF you lose some of the "reach" that attracted you to the long lens in the first place.


All of that being said, Ive had a lot of fun with the Tamron and gotten many images that I'm very happy with. (I've also gotten literally thousands of images that don't make it past the "import" stage. If we were still using film I'd have long ago gone bankrupt)

Spending the $1000 bucks for the long lens also means spending something in the neighborhood of $1000 for a very sturdy tripod AND most likely another $500 or so on a gimbal head.
Then lots of practice.

The alternative is to spend the $10K to buy the 600 f/4 and even heavier tripod and head.