Re: Portrait Lens Question
Not all P&S. The presets are usually called "focus free" and are very low end. [EMAIL PROTECTED] wrote: From: Chris Brogden <[EMAIL PROTECTED]> How do you account for the fact that p&s digital cameras can still blur the background for some portrait shots? With focal lengths around 7-12mm or so, pretty much everything should be in focus, shouldn't it? Hmmm, okay, I am a camera/photography ignoramus, but I remember hearing in class or reading somewhere that P&S are preset for a certain focusing distance. Like about 15 feet or something like that (maybe less, maybe 10). Regardless of where your subject actually is. Wouldn't that have something to do with it? Marnie aka Doe Probably not, probably way off base. ;-)
Re: Portrait Lens Question
From: Chris Brogden <[EMAIL PROTECTED]> How do you account for the fact that p&s digital cameras can still blur the background for some portrait shots? With focal lengths around 7-12mm or so, pretty much everything should be in focus, shouldn't it? Hmmm, okay, I am a camera/photography ignoramus, but I remember hearing in class or reading somewhere that P&S are preset for a certain focusing distance. Like about 15 feet or something like that (maybe less, maybe 10). Regardless of where your subject actually is. Wouldn't that have something to do with it? Marnie aka Doe Probably not, probably way off base. ;-)
Re: Portrait Lens Question
Hello, b_rubenstein wrote: > DOF is dependent on the set aperture and focal length of the > lens only. This > is why a 50mm lens has the same DOF, for a given f-stop, on a > film or partial frame DSLR. Not really... DOF is only dependent on two things: - actual aperture - magnification ratio (which is dependent on focal length AND distance) This is why a 50mm lens has the same DOF, for a given f-stop, on a film or partial frame DSLR ... IF the subject appears to be the same portion of the image. Chris Brogden wrote: > How do you account for the fact that p&s digital cameras can > still blur the background for some portrait shots? Unfortunatelly this is not typical, to say the least... :-((( Gabor
RE: Portrait Lens Question
DOF is related to absolute magnification (reproduction ratio) and aperture only. The answer to you final paragraph question is no they will not have same DOF because the image with the 28mm lens has less magnification and therefore will have better DOF J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Chris Brogden [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 24, 2003 10:02 PM To: [EMAIL PROTECTED] Subject: Re: Portrait Lens Question The big problem is finding a reputable site to look this up. Internet searches bring up so many conflicting answers, even from the so-called authoritative sites, that optical physics seems based more on opinion and limited experience than optical laws. So I wasn't questioning the validity of your answer; I was trying to see how my observations could be accounted for by the answer. This topic has come up on PDML several times before, and there are always at least two people, with two conflicting answers, who both insist that they are right. I'll hit the books sometime later and see what actual published works have to say about it, as I suspected edited materials will tend to be more accurate than most websites. So, just to clarify, if I take two photos--one with a 28mm lens and one with a 100mm lens--while standing in the same spot and shooting at the same aperture, and then enlarge a segment of the 28mm photo until it has the same coverage as the 100mm shot, the perspective will remain the same, but the DOF will be different? That's what I'm trying to understand... I thought that the DOF would be the same as well. Thanks, chris On Wed, 24 Sep 2003, Bruce Rubenstein wrote: > You make it sound like some sort of optical physics that I made up and have > to defend. I just try to keep track of what does what. Beyond that I would > suggest some independent research on the topic. Not to be snide, but I see > endless discussions and arguments over things here that can be looked up. > > BR > > From: Chris Brogden <[EMAIL PROTECTED]> > How do you account for the fact that p&s digital cameras can still blur > the background for some portrait shots? With focal lengths around 7-12mm > or so, pretty much everything should be in focus, shouldn't it?
Re: Portrait Lens Question
> > Depth of field is not focal length dependent. > >William Robb > No, but with the low reproduction ratio and small fstops most P&S digitals have, >there is going to be far more DOF than when using a typical 35mm film camera >JCO what the man said. all 4x6 prints of exactly the same scene (same magnification, to be precise) and the same aperture will be identical as far as DOF is concerned. regardless of format, focallength or whatever else. assuming perfect film/sensor, no diffraction, and so on. see the "Shallow DOF with 6X7 lenses" from this July best, mishka
Re: Portrait Lens Question
The big problem is finding a reputable site to look this up. Internet searches bring up so many conflicting answers, even from the so-called authoritative sites, that optical physics seems based more on opinion and limited experience than optical laws. So I wasn't questioning the validity of your answer; I was trying to see how my observations could be accounted for by the answer. This topic has come up on PDML several times before, and there are always at least two people, with two conflicting answers, who both insist that they are right. I'll hit the books sometime later and see what actual published works have to say about it, as I suspected edited materials will tend to be more accurate than most websites. So, just to clarify, if I take two photos--one with a 28mm lens and one with a 100mm lens--while standing in the same spot and shooting at the same aperture, and then enlarge a segment of the 28mm photo until it has the same coverage as the 100mm shot, the perspective will remain the same, but the DOF will be different? That's what I'm trying to understand... I thought that the DOF would be the same as well. Thanks, chris On Wed, 24 Sep 2003, Bruce Rubenstein wrote: > You make it sound like some sort of optical physics that I made up and have > to defend. I just try to keep track of what does what. Beyond that I would > suggest some independent research on the topic. Not to be snide, but I see > endless discussions and arguments over things here that can be looked up. > > BR > > From: Chris Brogden <[EMAIL PROTECTED]> > How do you account for the fact that p&s digital cameras can still blur > the background for some portrait shots? With focal lengths around 7-12mm > or so, pretty much everything should be in focus, shouldn't it?
Re: Portrait Lens Question
P&S cameras and lenses can blur anything. > > How do you account for the fact that p&s digital cameras can still blur > the background for some portrait shots? With focal lengths around 7-12mm > or so, pretty much everything should be in focus, shouldn't it? -- -- Collin Brendemuehl KC8TKA "Ron Santo deserves enshrinement in Cooperstown." -- Me --
Re: Portrait Lens Question
My E-10 has a 9-36 zoom, which for this sensor acts like a (roughly) 38-150 zoom in 35 mm. So at 9, it has the same perspective as a 38 and so on, at least as far as I can tell.
RE: Portrait Lens Question
From: "Chris Brogden" Subject: Re: Portrait Lens Question > > How do you account for the fact that p&s digital cameras can still blur > the background for some portrait shots? With focal lengths around 7-12mm > or so, pretty much everything should be in focus, shouldn't it? Depth of field is not focal length dependent. William Robb No, but with the low reproduction ratio and small fstops most P&S digitals have, there is going to be far more DOF than when using a typical 35mm film camera JCO
Re: Portrait Lens Question
> > How do you account for the fact that p&s digital cameras can still blur > > the background for some portrait shots? With focal lengths around 7-12mm > > or so, pretty much everything should be in focus, shouldn't it? > > Depth of field is not focal length dependent. > > William Robb Isn't it a combination of focal length and aperture? Maybe a silly question, but that's my impression. Bill
Re: Portrait Lens Question
- Original Message - From: "Chris Brogden" Subject: Re: Portrait Lens Question > > How do you account for the fact that p&s digital cameras can still blur > the background for some portrait shots? With focal lengths around 7-12mm > or so, pretty much everything should be in focus, shouldn't it? Depth of field is not focal length dependent. William Robb
Re: Portrait Lens Question
high depth of field is not infinite depth of field. no, it shouldn'd all be in focus. Herb - Original Message - From: "Chris Brogden" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, September 24, 2003 4:10 PM Subject: Re: Portrait Lens Question > How do you account for the fact that p&s digital cameras can still blur > the background for some portrait shots? With focal lengths around 7-12mm > or so, pretty much everything should be in focus, shouldn't it?
Re: Portrait Lens Question
How do you account for the fact that p&s digital cameras can still blur the background for some portrait shots? With focal lengths around 7-12mm or so, pretty much everything should be in focus, shouldn't it? chris On Wed, 24 Sep 2003 [EMAIL PROTECTED] wrote: > DOF is dependent on the set aperture and focal length of the lens only. This > is why a 50mm lens has the same DOF, for a given f-stop, on a film or partial > frame DSLR. > > BR > > > > From: Sylwester Pietrzyk <[EMAIL PROTECTED]> > > FOV at the same magnification scale should be equal with 35mm and *istD when > > > using the sme lens. *istD will have greater DOF than 35mm at equal distance > > to subject. But then you will see just a part of image seen on 35mm frame, > > thus you will have to make the distance between you and the subject greater > > to maintain equal magnification scale. Am I right? >
Re: Portrait Lens Question
DOF is dependent on the set aperture and focal length of the lens only. This is why a 50mm lens has the same DOF, for a given f-stop, on a film or partial frame DSLR. BR > From: Sylwester Pietrzyk <[EMAIL PROTECTED]> > FOV at the same magnification scale should be equal with 35mm and *istD when > using the sme lens. *istD will have greater DOF than 35mm at equal distance > to subject. But then you will see just a part of image seen on 35mm frame, > thus you will have to make the distance between you and the subject greater > to maintain equal magnification scale. Am I right?
Re: Portrait Lens Question
All perspective is set by the camera to subject distance. Period. Irrespective of the image format. If perspective is the driving factor (natural noses, ears, etc. or a specific exaggeration), then the length of the lens is selected for framing - to get the most out of the small 35mm or digital sensor frame. Sometimes perfection in perspective isn't necessary, and the lens is selected to give or accommodate a convenient photographer to subject distance. It's still all about making the most out of the available film/sensor real estate. Regards, Bob... "Do not suppose that abuses are eliminated by destroying the object which is abused. Men can go wrong with wine and women. Shall we then prohibit and abolish women?" -Martin Luther From: "Peter Loveday" <[EMAIL PROTECTED]> > I've not done much portrait work, and I have a question about portrait > lenses. > > Is the 'desirable' focal length of ~85mm to get a slightly flattened > perspective, in order to de-emphasise features on peoples faces etc? Or is > it to allow a good photographer to subject distance? Or both? > > Just curious about the ideal portrait lens on a *istD. Obviously the FOV > crop factor of 1.5 means that a 50mm lens has the same field of view as a > 75mm lens, but, still being 50mm focal length has the same perspective on > any camera. If the perspective was the main concern here, then still having > an 85mm lens would be ideal, but then the FOV would be a lot tighter and > might necessitate a lot larger distance to the subject.
Re: Portrait Lens Question
on 24.09.03 15:24, Peter Loveday at [EMAIL PROTECTED] wrote: > Just curious about the ideal portrait lens on a *istD. Obviously the FOV > crop factor of 1.5 means that a 50mm lens has the same field of view as a > 75mm lens, but, still being 50mm focal length has the same perspective on > any camera. If the perspective was the main concern here, then still having > an 85mm lens would be ideal, but then the FOV would be a lot tighter and > might necessitate a lot larger distance to the subject. FOV at the same magnification scale should be equal with 35mm and *istD when using the sme lens. *istD will have greater DOF than 35mm at equal distance to subject. But then you will see just a part of image seen on 35mm frame, thus you will have to make the distance between you and the subject greater to maintain equal magnification scale. Am I right? -- Best Regards Sylwek
Portrait Lens Question
I've not done much portrait work, and I have a question about portrait lenses. Is the 'desirable' focal length of ~85mm to get a slightly flattened perspective, in order to de-emphasise features on peoples faces etc? Or is it to allow a good photographer to subject distance? Or both? Just curious about the ideal portrait lens on a *istD. Obviously the FOV crop factor of 1.5 means that a 50mm lens has the same field of view as a 75mm lens, but, still being 50mm focal length has the same perspective on any camera. If the perspective was the main concern here, then still having an 85mm lens would be ideal, but then the FOV would be a lot tighter and might necessitate a lot larger distance to the subject. Thanks! Love, Light and Peace, - Peter Loveday Director of Development, eyeon Software
