It was 21/12/02 3:52 am when Rick Lee wrote: >> Any comments?<< > > I can't comment really... I guess I just expect focus to be more critical > zoomed in than out. >
Rick - Talking to Paul Lawrence off list I remembered something from my film (as in motion pictures) days. I think it may explain why the focus shifted as I was zooming in and out with the 24-85-G Nikkor: ---> > I have just tried to replicate this and I can't see any difference using > my Sigma 24-70EX. I seem to recollect reading a technical piece I think > from Carl Zeiss discussing true zoom lenses and variable focal length > lenses - one hold focus when you zoom whilst the other has to be > re-focused after zooming and I understand most still camera zoom lenses > have to be refocused after zooming. So the old trick of zooming in, focusing, zooming out is not so reliable after all. Come to think of it, when people use stills zooms on film cameras, they have to be modified so that they can hold their focus throughout the zoom length. DUH! A lot of film cameramen use the Canon 300-600 (I've never used it) or some of the Nikon zooms I seem to remember. <--- --/ Shangara Singh http://www.e-pixel.co.uk Adobe Certified Expert ~ Photoshop 7.0 PortfoliosOnCD for Photographers http://www.portfoliosoncd.com =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
