I checked all my zooms and the ones I use are all autofocus and probably shift focus during zoom. Autofocus zooms are not the best lenses for manual focus experiments. I don't need or want "fixed focus" zooms on my (D)SLR's. A videocam should have a fixed focus zoomlens.
I don't have the zoom gear to check your claims. I must assume you checked your claim and found it to be true for your eyes, pentaprism, focussing screen, testsubject etc. 1000mm/8.0 thats probably a mirror lens. Focusing my 500mm mirror is a real pain. I have never seen a 20mm/8.0. Focussing my 16mm/2.8 Zenitar is easy. My longest is 560mm/6.8. It's a Novoflex fastshot which helps a lot during focussing. Comparing a 1000mm/8.0 against a non existing 20mm/8.0 is mind experiment. Please post some pictures and/or url's. On 11/11/06, J. C. O'Connell <[EMAIL PROTECTED]> wrote: > You are confusing depth of field with accurate focus. > If you dont care about the depth of field and all > you care about is if your subject falls SOMEWHERE > in the depth of field you might have a point, but > most photographer focus on a specific distance > even with high depth of field condtions to control > the foreground and background DOF zones around > the subject. I know I do, especially when wide > f-stops/shallow DOF conditions exist. > > Ever used a 35mm F2 at F2? I have, and you definately > need to focus it. Your longest glass might be your > most difficult to focus but if you have wides at the > same speed they would be even harder. What speed is you > longest manual glass? Mine is a 1000mm/F8 and its > easier to focus than a say a 20mm F8 would be, I can tell > you that. > > As for armchair comment, I have been using SLRS > to take photos for over 30 years so your comments > are without merit. I dont just guess about these things, > they are based on both long experience with many > many cameras and lenses of all types and all the optical > theory I have learned over the years. > > Are you saying you dont find zooms eaeier to focus > more accurately at the long end, too? Because if > you are, I cant believe it, as I have never found that > to not be the case with any zoom I have ever used. > > jco > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of > Toine > Sent: Saturday, November 11, 2006 3:55 AM > To: Pentax-Discuss Mail List > Subject: Re: Using a Super Tak w/ istDS- A challange to the list? > > > I do. In fact I don't need to focus at all using wide lenses. And my > longest manual glass is the most difficult to focus. Are you sure you're > not an arm chair photographer (nothing wrong with that). I can't > remember any pictures. > > On 11/10/06, J. C. O'Connell <[EMAIL PROTECTED]> wrote: > > OK, I challenge the entire list on the matter. > > Does anyone here actually find or believe that > > wider lenses are just as easy to focus as > > 3X longer lenses at the same fstop? I have > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
