Thanks Hopz
Well its such a good price its a no brainer for me but its not really soothing you can just put in the bag lol its a bit ott.
I use auto ISO all the time, one less thing to worry about. I set it from 100-6400 and leave it be. The quality is so good all the way to 3200 that I don't worry about it like I used to. As you can see in the rhino pic its 2500iso, that would have been unusable 5 years ago. Now it looks like 800 amazing. Also if your shooting in good light using higher ISO, it doesn't show too much quality degradation. Problems arise when your shooting high and theres not a lot of light noise is much more apparent.
You do loose a bit of colour and obviously increases the noise, but for wildlife, you have to shoot up high sort of around 800-2000 because of A, the length of the lens, at 600 you have to be shooting at 1/600th or higher. It was also my first time out with the lens so I wanted to be cautious and B, the animal movement. Sheep for example grind their teeth when they eat grass and that vibrates the whole head and torso so if you try shooting at 1/100th which might sound fine if you zoom to 100% you'll find its not tack sharp, but a bit blurry. All animal have these traits and I've learned these lessons hard in the past. They also move quickly and unpredictably so shooting fast means you will be ready too.
Another reason its high is because I'm shooting at F8 because on full frame DOF is smaller than on a crop camera, this lens is also slow with a smallest aperture of F6.3 and a lot of the time these animals have dark fur so its upping the ISO to balance the exposure. ISO is the third part of the exposure triangle along with the aperture and shutter speed. I was shooting manual at F8 and 1/1000th so the only way to change the exposure is to change the ISO.
If you also look I was changing the shutter speed up and down too as some of the animals were pretty static as you do really want to shoot lower down in the ISO for the best quality but as I probably won't use these and was more a lens test I wasn't overly fussed. I do tend to shoot like this now anyway but I usually have much faster glass so the ISO is much lower. ISO is so good on these newer cameras i don't think its that much of a problem.