tiggy Offline Upload & Sell: On
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p.1 #18 · p.1 #18 · Those darn push-pull zoom lenses: how to operate without frustration | |
Thanks everyone for the sense of how you all overcame this awkwardness. Not the answer I wanted, as I was hoping there was a magic stance/grip/etc. that would fix this for me.
To answer some questions:
- I am using a gimbal on a tripod for birds in flight (and hyperkinetic three year old daughter in flight too), and I find that I'm often using a 1.4x teleconverter, which throws me to manual focus. I am actually getting so that I can do that trick where you start out at 100mm for framing, and then zoom in to get the magnification, but of course there is a slight focus adjustment needed. If I use the focus ring as the thing my left hand holds onto to operate the "trombone effect," then I can also twist the ring at the same time. I think perhaps I'm just being overly-ambitious in what a person can do, but I'll keep trying to see if I can get better at it. I've been practicing on falling leaves and dragonflies (and a running three-year-old).
- One trip of here is that if the locking ring is at all tightened for tension purposes, the focus movement also moves the locking ring, which is a bound to mess things up. The several posts here indicating that the "tension ring" is really a misnomer and it should be used as a locking mechanism, or completely loose now makes a lot of sense to me seeing that. I believe that might help with the original problem. I was previously setting a medium tension with that ring, which might just be looking for trouble.
- One note: I microfocused the lense yesterday, and it required 8 units of movement (out of a possible 20) to get a proper focus plane at 400mm, and it requires 16 out of 20 units at the 100mm setting. The new 70D allows you to set both. This was part of my problem too, as I was not getting the sharpness I wanted, and I was blaming the manual focus ring and my own amateur skills. Now I realize it was my amateur skills and the a bit of backfocusing too. I should also say that I think it's not a great quality control indicator when the microfocusing of a brand new L-series lens requires 80 percent of the available microfocusing distance as a modification to put the focus plane in its proper place. In this microfocusing process, I was pixel peeping, and I could see that there could be sharpness improvements on this lens when you're looking at 100 percent crops. It's about acceptable, but I do wonder how much sharper a prime lens would be. Not that I could afford one.
Thanks everyone for the guidance. Great forum, and I'm very happy I joined. -tig
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