Lens question
in [Digital Cameras]
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From: John Navas on 4 Nov 2009 00:07 On Tue, 3 Nov 2009 19:09:50 -0800 (PST), -hh <recscuba_google(a)huntzinger.com> wrote in <9b422e32-d03c-4489-8106-cf6a738c89fc(a)c3g2000yqd.googlegroups.com>: >John Navas <spamfilt...(a)navasgroup.com> wrote: >> -hh wrote: >> [other attributions] >> >> >>Versus a dSLR combination of 448mm at f/4.0 .. >> >> >> >What lens (including price, size and weight, >> >> >and how long you've owned it)? >> >> [stuff edited out by John] >> >> >> >[another choice is] The Canon EF 75-300mm f/4.0-5.6 III sells for $160, >> >although it is f/5.6 whereas John is curious because I specifically >> >mentioned it having an f/4.0 solution. ... >> >> Mediocre lens. No thanks. > >Sure, there's better (such as my f/4 solution), but this lens is >adequate for all of those "typical" uses, such as 4"x6" prints and >online Web presentation, that we hear justifies a P&S because >proverbially no one ever needs the big dSLR/lens 'overkill' to make >huge prints. Not even close to the Leica super-zoom lens on the Panasonic. Thanks for proving my point. -- Best regards, John Buying a dSLR doesn't make you a photographer, it makes you a dSLR owner. "The single most important component of a camera is the twelve inches behind it." -Ansel Adams
From: Ray Fischer on 4 Nov 2009 00:12 John Navas <spamfilter1(a)navasgroup.com> wrote: >On Tue, 3 Nov 2009 19:09:50 -0800 (PST), -hh ><recscuba_google(a)huntzinger.com> wrote in ><9b422e32-d03c-4489-8106-cf6a738c89fc(a)c3g2000yqd.googlegroups.com>: > >>John Navas <spamfilt...(a)navasgroup.com> wrote: >>> -hh wrote: >>> [other attributions] >>> >> >>Versus a dSLR combination of 448mm at f/4.0 .. >>> >>> >> >What lens (including price, size and weight, >>> >> >and how long you've owned it)? >>> >>> [stuff edited out by John] >>> >>> >>> >[another choice is] The Canon EF 75-300mm f/4.0-5.6 III sells for $160, >>> >although it is f/5.6 whereas John is curious because I specifically >>> >mentioned it having an f/4.0 solution. ... >>> >>> Mediocre lens. No thanks. >> >>Sure, there's better (such as my f/4 solution), but this lens is >>adequate for all of those "typical" uses, such as 4"x6" prints and >>online Web presentation, that we hear justifies a P&S because >>proverbially no one ever needs the big dSLR/lens 'overkill' to make >>huge prints. > >Not even close to the Leica super-zoom lens on the Panasonic. Bullshitting is a poor substitute for facts. -- Ray Fischer rfischer(a)sonic.net
From: David J Taylor on 4 Nov 2009 01:38 "No spam please" <me(a)spamnotwelcome.org> wrote in message news:hcpro9$1mab$3(a)adenine.netfront.net... [] > I'd better clarify the comment about the 747. > If one system on the aircraft (the fuel gauge system) was not immune to > intererference from another system on that aircraft (the radio > transmitters) then why should we expect any immunity from electronic > systems brought on board by passengers? > > Regards, Rog. Rog, It's because interference to a non-radio system from a transmitter is most likely to be due simply to the field-strength of transmitted signal, than to its exact frequency or modulation type. I.e. the signals emitted by a non-transmitting consumer electronic system are of a much lower field strength. There is probably no sensitive radio receiver in the fuel gauge system. That's why it's a reasonable expectation - in general. I should add that I don't know details of the specific systems involved, though, I'm talking in general. David
From: David J Taylor on 4 Nov 2009 01:44 "Dudley Hanks" <dhanks(a)blind-apertures.ca> wrote in message news:ES%Hm.50390$Db2.20586(a)edtnps83... [] > I believe Canon calls it "digital zoom," which is at least a bit more > honest. Using the word "optical" implies something to do with the lens > elements, which of course it is completely different. > > Take Care, > Dudley No, digital zoom is something else. In the digital zoom systems I've used the camera output remains at the nominal number of megapixels, so a 200% digital zoom on an 8MP sensor uses the middle 2MP, but interpolates the result to 8MP. Under some circumstances this can be useful - I've made tests where the JPEG from a digital zoom image is marginally better than a 2:1 resize in post-processing. A 200% "extended optical zoom" simply outputs the middle part of the image as a 2MP image. In both cases, by only using the central part of the image, the focus and exposure measurement functions can be restricted to a smaller part of the total image, and may therefore, be faster or more accurate. I have turned off the digital zoom on my cameras, though. Cheers, David
From: Dudley Hanks on 4 Nov 2009 02:12
"David J Taylor" <david-taylor(a)blueyonder.not-this-bit.nor-this.co.uk.invalid> wrote in message news:Fp9Im.1484$Ym4.421(a)text.news.virginmedia.com... > "Dudley Hanks" <dhanks(a)blind-apertures.ca> wrote in message > news:ES%Hm.50390$Db2.20586(a)edtnps83... > [] >> I believe Canon calls it "digital zoom," which is at least a bit more >> honest. Using the word "optical" implies something to do with the lens >> elements, which of course it is completely different. >> >> Take Care, >> Dudley > > No, digital zoom is something else. In the digital zoom systems I've used > the camera output remains at the nominal number of megapixels, so a 200% > digital zoom on an 8MP sensor uses the middle 2MP, but interpolates the > result to 8MP. Under some circumstances this can be useful - I've made > tests where the JPEG from a digital zoom image is marginally better than a > 2:1 resize in post-processing. A 200% "extended optical zoom" simply > outputs the middle part of the image as a 2MP image. > > In both cases, by only using the central part of the image, the focus and > exposure measurement functions can be restricted to a smaller part of the > total image, and may therefore, be faster or more accurate. > > I have turned off the digital zoom on my cameras, though. > > Cheers, > David So, the Panasonic's extended optical zoom over-rides the image size selection and outputs a smaller image as you progressively zoom out? That would be roughly equivalent to using the digital zoom on a Canon and setting the image to a smaller size? Take Care, Dudley |