HA HA HA HA, your test is very flawed. I never said you couldn't accurately focus any lens, I said its harder to focus the wider one accurately. That means you need to take more time and be more careful to find the point of true focus. What you did only proves that you COULD focus two lenses accurately and says nothing of how easy/hard it was to achieve the focus on each. NO WONDER you came to your false conclusion, your test was flawed. jco
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of William Robb Sent: Tuesday, November 14, 2006 7:41 PM To: Pentax-Discuss Mail List Subject: Re: Using a Super Tak w/ istDS- A challange to the list? ----- Original Message ----- From: "Christian" Subject: Re: Using a Super Tak w/ istDS- A challange to the list? > Bill is using the "personal experience" argument. Conduct an > experiment and evaluate the results. This is very different from the > "personal opinion" argument. Granted, Bill is evaluating his > experience subjectively and it is only based on his experience, but > JCO made a blanket statement that "ALL people can focus long lenses > easier than short lenses (at a given f-stop)." So the argument has > turned into one > or two people's experience that show otherwise and JCO's blanket > statement which, without his own evaluation (he doesn't need to prove > anything to us with experience), is just his opinion. I just noted an exception to the rule. I used to teach this stuff, I expect I am as well versed in optical and photographic theory as most anyone on this list. At no time have I said that the optical theory that John has presented is fallacious. I have said that I found that in one given set of circumstances, with one particular camera and two particular focal lengths of lenses that there is no practical difference in focusing difficulty. I did this by setting a 105mm lens to f/8, hitting the DOF preview and focusing it, then releasing the DOF and seeing if I could improve the focus. I then repeated the above with a 40mm lens, and noted that in both cases, the focus had been critically secured when stopped down. That it's suddenly become a battle for the idealogue of the list and his sycophant is really kind of sad. They need to get lives. William Robb -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
