Years ago, when I was at uni I was taught to focus a broadcast studio camera by zooming in on the subject (a news reader typically), focus and then pull out to the desired shot. This is something that's stuck with me and is now second nature, but as I start in the realm of digital photography is this doing me more harm than good?
When zooming a DSLR , does that change the focal point such that if I were to (for example) zoom in to 150mm on my telephoto, focus and then pull out to 50mm for the shot, might my subject no longer be in focus? Particularly when one introduces considerations into , is this why my captures aren't always as as I'd hope? Or is it still a reasonable technique?
If it's not a good way to focus, does anyone have any tips on getting pure crisp shots? Should one always focus at the focal length to be used for the shot?
Whilst we're on the subject, I used to think that to 'focus to infinity' meant just to turn the focus wheel all the way and be done with it...now I'm thinking I must consider my and focal length settings and figure out the hyperfocal length and focus on a plane at that distance, but this seems very long-winded for people to do for every shot. I know there's always AF, but I'd like to have this cleared up, if at all possible.
I know I should understand this already but my shots just don't always come out as crisp as I'd like and I'm trying to get to the bottom of why.
Thanks for your time with this rookie issue.