Hi Jack, it was very dark this morning, shutter speeds anywhere from 1/30 down to 1/8. I'm not known for steadiness anyway and this was after 2 1/2 pots of coffee! ;-)
Da-Da-Da-Da-Don (*Enough* with the coffee already!) ;-) > -----Original Message----- > From: Jack Davis [mailto:[EMAIL PROTECTED] > Sent: Sunday, September 04, 2005 7:09 PM > To: [email protected] > Subject: RE: A50/1.4 versus M50/1.4, Comment Please > > > Don, > Have been casually following this thread and finally > have a question. Your last post included the > comment;"a good bit of motion blur" even though all 22 > frames were apparently shot "wide open". (f/2). Poor > lighting and dull subject? > Under the circumstances, it would seem difficult to > assign blame to lens. > I own an M 50 f/1.4 (also an A f/2 that came with a > Super Program a few years ago)) and I'll try some > shots at f/1.4. I'll use a heavy tripod, mlu and self > timer. They'll be on film, so will take a little > longer. > > Jack > > --- Don Sanderson <[EMAIL PROTECTED]> wrote: > > > Thanks Godfrey, for going to all that work. > > I think I've just reached the point that either the > > A50, or my attitude, > > needs an overhaul. > > I am 100% certain that there is nothing wrong with > > the lens. > > Either my eyes, camera, attitude, or a combination > > of them is > > my problem. > > I have had good shots with this lens on the D, but > > they're > > more the exception than the rule. > > I went out after a rainstorm this morning with the D > > wearing an > > older (all metal) M50/2 I had just cleaned. > > 22 shots, all wide open, and not a single seriously > > mis-focused > > one. (Good bit of motion blur though!) ;-( > > Granted the smaller stop is a big help, but it's > > just strange that > > I can't do this with the brighter lens. > > Oh well, ya gotta use what works. ;-) > > > > Thanks again for the tests. > > > > Don > > > > > -----Original Message----- > > > From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] > > > Sent: Sunday, September 04, 2005 4:28 PM > > > To: [email protected] > > > Subject: Re: A50/1.4 versus M50/1.4, Comment > > Please > > > > > > > > > Don, > > > > > > Your tests with the 50mm lenses made me interested > > to do a little > > > testing, since I have F50/1.7, A50/1.4, A50/1.7, > > and A50/2 lenses at > > > present. I also have a K50/1.4 lens belonging to > > another PDMLer which > > > needed a quick test because the box it was shipped > > in was so crushed > > > in shipment to me (I'm handing this lens off to > > yet another PDMLer.. > > > yeah, complicated). > > > > > > I set up the tripod and DS body on my porch, used > > a set of U-Haul > > > moving boxes (for their printed matter) at about > > 10' distance as a > > > focusing target. My F50/1.7 has been the only > > "problematic" Pentax > > > lens on AF I've got ... it is the only one that > > regularly doesn't > > > focus smoothly and quickly ... so I started with > > that. I set aperture > > > wide open, set exposure via Av for the F and A > > series lenses, set the > > > same exposure manually for the K, and made two > > exposures each: one > > > focused manually by eye, one focused manually with > > the 2x magnifier. > > > I made an additional exposure with the F50 using > > AF. I wasn't looking > > > at OOF rendering or other characteristics in this > > test, just near- > > > center resolution/contrast and my ability to focus > > the lenses > > > accurately. > > > > > > The results: > > > - For all lenses, a noticeable change in focus was > > seen with the 2x > > > magnifier when making a focus ring change of less > > than 10 degrees. > > > The F50 ring has the shortest turn and is the most > > sensitive to > > > change. The focus indicator light is illuminated > > through 10-15 > > > degrees turn of the focus ring with all of these > > lenses, so for f/1.7 > > > and f/1.4 lenses, it simply cannot be trusted at > > wide open aperture. > > > > > > - F50/1.7 focused very poorly on AF with this > > target. Out of 5 tries > > > (set focus on my hand at 20 inches, let refocus on > > the target), four > > > were badly defocused, the fifth was passable only. > > Focused manually, > > > it produced the sharpest and clearest image. > > > > > > - Differences between the A50/1.4 and K50/1.4 are > > small but > > > noticeable. The A50 is sharper and more contrasty > > wide open, lead to > > > greater focusing accuracy with either eye or > > magnifier. Both require > > > some delicacy and patience in setting critical > > focus... even a tiny > > > movement of the focus ring can throw them off the > > best setting. > > > > > > - The A50/1.7 was almost the same as the F50, > > although *slightly* > > > less contrasty. Perhaps they improved the lens > > coatings between the A > > > and F versions at tiny bit? The difference is > > within my average focus > > > error, it seems. The A50/2 was also surprising > > close to the A50/1.7 > > > on center too, although corners and edges fell off > > more. > > > > > > - The use of the 2x magnifier helps, but it still > > requires patience > > > and care to set accurate focus with such a large > > lens opening at this > > > distance. Three out of the five sets showed no > > significant difference > > > in focusing by eye, vs with the magnifier, one was > > better and one > > > slightly worse. That says to me that it helps but > > only to a limited > > > degree, at least on this kind of target. > > > > > > I would certainly not refer to any of these lenses > > as "unusable" at > > > wide open aperture, however. More difficult to > > focus, yes; not as > > > desirable on certain types of subject matter, > > maybe. But all of them > > > turned a creditable quality image for wide open > > work, as long as you > > > make an effort to focus them accurately. > > > > > > > > http://homepage.mac.com/godders/50mm-focus-snips.jpg > > > > > > Godfrey > > > > > > > > > On Sep 3, 2005, at 3:13 PM, Don Sanderson wrote: > > > > > > > Thanks Rob, that's about what I found on these > > when on the ist-D. > > > > It's nice to have the bright finder but if it > > won't focus for me > > > > anyway it's no advantage. > > > > The thing is I never had a problem wide open > > with the M on film. > > > > The _good_ thing is the FA50/1.7 seems to really > > shine when used > > > > on the digital. > > > > Live and learn. I happy now and I'm sure someone > > will enjoy the A. > > > > > > > > Don > > > > > > > > > > > > > > > >> -----Original Message----- > > > >> From: Robert Whitehouse > > [mailto:[EMAIL PROTECTED] > > > >> Sent: Saturday, September 03, 2005 4:52 PM > > > >> To: [email protected] > > > >> Subject: RE: A50/1.4 versus M50/1.4, Comment > > Please > > > >> > > > >> > > > >> Don, > > > >> > > > >> I also own an "M" 50/1.4 and an "A" 50/1.4. > > > >> > > > >> I found that they are both just about un-usable > > at f1.4 and I > > > >> wouldn't try > > > >> unless I am desperate. > > > >> > > > >> However, by the time you get to f2.8 they are > > both fine and at > > > >> f4.0 they are > > > >> the sharpest lenses that I have - I know that I > > can get great > > > >> results with > > > >> portraits at f4.0 to f5.6 on both film and > > digital. > > > >> > > > >> Rob W > > > >> > > > >> > > > >> > > > >> -----Original Message----- > > > >> From: Don Sanderson > > [mailto:[EMAIL PROTECTED] > > > >> Sent: 03 September 2005 02:44 > > > >> To: PDML > > > >> Subject: A50/1.4 versus M50/1.4, Comment Please > > > === message truncated === > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? 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