Lens question
in [Digital Cameras]
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From: David J Taylor on 4 Nov 2009 02:28 "Dudley Hanks" <> wrote in message news:GP9Im.50457$Db2.22371(a)edtnps83... [] > So, the Panasonic's extended optical zoom over-rides the image size > selection and outputs a smaller image as you progressively zoom out? As I understand it, yes. > That would be roughly equivalent to using the digital zoom on a Canon > and setting the image to a smaller size? > > Take Care, > Dudley When you say "setting the image to a smaller size", Dudley, if you mean setting the camera to 5MP rather then 10MP, the answer is no, it's not equivalent. Setting the image to a smaller size on the Canon still uses the full sensor area, and doesn't change the field of view. It simply interpolates the 10MP sensor down to 5MP (or whatever is chosen). The extended optical zoom is more equivalent to taking a 10MP image, and cropping it in the camera down to 5MP. Perhaps what's what you meant, though. Cheers, David
From: Dudley Hanks on 4 Nov 2009 02:53 "David J Taylor" <david-taylor(a)blueyonder.not-this-bit.nor-this.co.uk.invalid> wrote in message news:E2aIm.1500$Ym4.1093(a)text.news.virginmedia.com... > "Dudley Hanks" <> wrote in message news:GP9Im.50457$Db2.22371(a)edtnps83... > [] >> So, the Panasonic's extended optical zoom over-rides the image size >> selection and outputs a smaller image as you progressively zoom out? > > As I understand it, yes. > >> That would be roughly equivalent to using the digital zoom on a Canon and >> setting the image to a smaller size? >> >> Take Care, >> Dudley > > When you say "setting the image to a smaller size", Dudley, if you mean > setting the camera to 5MP rather then 10MP, the answer is no, it's not > equivalent. Setting the image to a smaller size on the Canon still uses > the full sensor area, and doesn't change the field of view. It simply > interpolates the 10MP sensor down to 5MP (or whatever is chosen). > > The extended optical zoom is more equivalent to taking a 10MP image, and > cropping it in the camera down to 5MP. Perhaps what's what you meant, > though. > > Cheers, > David Yes, the latter is what I meant. I realize that simply setting the image to a smaller size will interpolate a full sensor image down to the smaller rez, but I was thinking about the smaller size being selected in conjunction with the digital zoom being used. I don't think the firmware would up-size the digitally zoomed image only to have to down-size it again back to something equivalent to the portion "zoomed" in to. Take Care, Dudley
From: David J Taylor on 4 Nov 2009 03:06 "Dudley Hanks" <dhanks(a)blind-apertures.ca> wrote in message news:fqaIm.50462$Db2.10523(a)edtnps83... [] > I realize that simply setting the image to a smaller size will > interpolate a full sensor image down to the smaller rez, but I was > thinking about the smaller size being selected in conjunction with the > digital zoom being used. > > I don't think the firmware would up-size the digitally zoomed image only > to have to down-size it again back to something equivalent to the > portion "zoomed" in to. > > Take Care, > Dudley Correct - it's not a double operation in the firmware, just a simple in-camera crop. Like digital zoom, it may have the advantage that functions like exposure or focus measurement can be carried out on fewer pixels, in the wanted part of the image, and may therefore be faster or more accurate. Digital zoom then simply expands the result of a crop to create the number of pixels the user expects. Cheers, David
From: -hh on 4 Nov 2009 07:15 Ray Fischer wrote: > John Navas <spamfilt...(a)navasgroup.com> wrote: > > -hh <recscuba_goo...(a)huntzinger.com> wrote: > >>Sure, there's better (such as my f/4 solution), but > >> [the Canon EF 75-300mm] 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. Its also hypocrisy: since "not even close" is claiming vastly higher performance, this means that it is 'overkill' for the general application, and since it cost more than $160, then he paid 'extra' for something not needed. The only difference between what John does and what he criticizes is merely the magnitude of the infraction. FWIW, I probably could have offered some images to 'defend' Canon's 75-300 lens series, such as: <http://www.huntzinger.com/photo/2004/peru/SV_cock-of-rock-ff_ (24_0445).jpg> (full frame) ....but the shots aren't comparable in several ways, not the least of which is that it represents 'worst case' conditions: the 75-300 is known to be soft when wide open at full extension, and this shot was under a heavy tree canopy which made it ~5 stops darker than John's comparatively easy full sunlight photo. Similarly, it was shot on film, which precluded easy/fast bumping of ISO, so combined with it being handheld, there's blur from its very slow shutter speed (1/30sec). Finally, it was only later digitized, which introduces a loss step as well. I haven't sold off the lens, so perhaps I'll try some new shots with a digital SLR body in the next month. I'll try to make them closer to the "Sunny 16" conditions that John had, for sake of parity. -hh
From: Outing Trolls is FUN! on 4 Nov 2009 08:09
On Wed, 4 Nov 2009 04:15:26 -0800 (PST), -hh <recscuba_google(a)huntzinger.com> wrote: > >...but the shots aren't comparable in several ways, not the least of >which is that it represents 'worst case' conditions: the 75-300 is >known to be soft when wide open at full extension, and this shot was >under a heavy tree canopy which made it ~5 stops darker than John's >comparatively easy full sunlight photo. Similarly, it was shot on >film, which precluded easy/fast bumping of ISO, so combined with it >being handheld, there's blur from its very slow shutter speed >(1/30sec). Finally, it was only later digitized, which introduces a >loss step as well. And there was a stone in your shoe, your girdle was too tight, you forgot your glasses, there was a string broken in your tennis racket, and your shoelace was untied ... yadda yadda yadda ... |