Lens 'distance scale' window.
Hi all, I am used to my older lenses that always had a 'Depth of Field' scale on them. This DOF scale was sometimes refered to as 'Depth Of Focus'. You could tell at a glance what the different Depth of Field you would have for your shot by looking at the (distance) lines that corresponded to the aperture you were using. I really found this very valuable because you could use the info to change your actual focus point to get more or less foreground/background in focus. On my Sigma 10~20mm DC EX lens it has a window that the book refers to as a 'distance scale'. The scale reads from .8', 1', 1.5' 3', & infinity. adjacent to this window it has a line called a 'Focus Index Line'. I am trying to figure out what it all means ~ can anybody enlighten me please. Darryl
The colored-lines aperture scale on older lenses is used to set lens focus to the "hyper-focal distance", which is the lens position that captures "infinity" to near-focus in DOF, depending on the aperture selected. The smaller the aperture (larger number) the greater the DOF. Auto-focus will not achieve maximum hyper-focal DOF.
Basically, you manually set focus by positioning the infinity sign at the farthest colored line that corresponds to your chosen aperture. Every distance to the matching colored line will also be in focus.
Just looked at my Sigma 10 ~ 20mm lens, and yes, the markings are distances in feet. The line will be the distance at which the lens is focussed, if using manual focus. But the DOF with this lens is so deep, one should not have to worry too much about being out of focus.
Pablo8 wrote:
Just looked at my Sigma 10 ~ 20mm lens, and yes, the markings are distances in feet. The line will be the distance at which the lens is focussed, if using manual focus. But the DOF with this lens is so deep, one should not have to worry too much about being out of focus.
Thanks for that Pablo - yes the 10~20 has a massive DOF......
Nikonian72 wrote:
The colored-lines aperture scale on older lenses is used to set lens focus to the "hyper-focal distance", which is the lens position that captures "infinity" to near-focus in DOF, depending on the aperture selected. The smaller the aperture (larger number) the greater the DOF. Auto-focus will not achieve maximum hyper-focal DOF.
Basically, you manually set focus by positioning the infinity sign at the farthest colored line that corresponds to your chosen aperture. Every distance to the matching colored line will also be in focus.
The colored-lines aperture scale on older lenses i... (
show quote)
Hi Nikonian, thank you for the answer - I am aware of my aperture settings as regards my DOF. My problem is the lens doesn't have any of the coloured lines that represented your focal range (on the older lenses) - it only has one single white line in the middle of the window (the book refers to this as the 'Focus Index Line'). I am thinking maybe you use the window itself as your upper and lower focus points ie: whatever distance is in the window is all in focus. This window is probably only suitable for close up work because the range is only from .8ft~3ft and infinity. If I want to focus on something 30 feet away the whole window seems superfluous.
I wasn't aware that 'auto-focus' wont achieve maximum Hyper-focal DOF. Thanks for your help. Darryl
birdpix
Loc: South East Pennsylvania
Darryl88 wrote:
Nikonian72 wrote:
The colored-lines aperture scale on older lenses is used to set lens focus to the "hyper-focal distance", which is the lens position that captures "infinity" to near-focus in DOF, depending on the aperture selected. The smaller the aperture (larger number) the greater the DOF. Auto-focus will not achieve maximum hyper-focal DOF.
Basically, you manually set focus by positioning the infinity sign at the farthest colored line that corresponds to your chosen aperture. Every distance to the matching colored line will also be in focus.
The colored-lines aperture scale on older lenses i... (
show quote)
Hi Nikonian, thank you for the answer - I am aware of my aperture settings as regards my DOF. My problem is the lens doesn't have any of the coloured lines that represented your focal range (on the older lenses) - it only has one single white line in the middle of the window (the book refers to this as the 'Focus Index Line'). I am thinking maybe you use the window itself as your upper and lower focus points ie: whatever distance is in the window is all in focus. This window is probably only suitable for close up work because the range is only from .8ft~3ft and infinity. If I want to focus on something 30 feet away the whole window seems superfluous.
I wasn't aware that 'auto-focus' wont achieve maximum Hyper-focal DOF. Thanks for your help. Darryl
quote=Nikonian72 The colored-lines aperture scale... (
show quote)
No, you can't use the edge of the window itself as the range for determining the depth of field. With that wide angle lens, the gradations between 3 ft and infinity become progressively so small as to be meaningless.
Depth of field, as you know, also varies with focal length. this creates problems with, let's say a 50-300 mm zoom. How do you display that range? With old film era zooms the scale was fan shaped and more or less of the scale was visible because the lens barrel moved in and out with the zoom function. How do yu do that with some of these internal zoom lenses?
The real solution is for the camera manufacturers to make determining Hyperfocal Distance a software function. A calculator could be built in and displayed on the LCD screen. In fact, that wouldn't even be necessary. A simple press of a button would set the focus at the HFD for that lens at the selected zoom and f/stop all based on a generous print size. The camera body already knows what focal length lens is on the camera and can focus the lens to a predetermined distance as these are already a part of the Exif data.
Simple, huh!
birdpix wrote:
Darryl88 wrote:
Nikonian72 wrote:
The colored-lines aperture scale on older lenses is used to set lens focus to the "hyper-focal distance", which is the lens position that captures "infinity" to near-focus in DOF, depending on the aperture selected. The smaller the aperture (larger number) the greater the DOF. Auto-focus will not achieve maximum hyper-focal DOF.
Basically, you manually set focus by positioning the infinity sign at the farthest colored line that corresponds to your chosen aperture. Every distance to the matching colored line will also be in focus.
The colored-lines aperture scale on older lenses i... (
show quote)
Hi Nikonian, thank you for the answer - I am aware of my aperture settings as regards my DOF. My problem is the lens doesn't have any of the coloured lines that represented your focal range (on the older lenses) - it only has one single white line in the middle of the window (the book refers to this as the 'Focus Index Line'). I am thinking maybe you use the window itself as your upper and lower focus points ie: whatever distance is in the window is all in focus. This window is probably only suitable for close up work because the range is only from .8ft~3ft and infinity. If I want to focus on something 30 feet away the whole window seems superfluous.
I wasn't aware that 'auto-focus' wont achieve maximum Hyper-focal DOF. Thanks for your help. Darryl
quote=Nikonian72 The colored-lines aperture scale... (
show quote)
No, you can't use the edge of the window itself as the range for determining the depth of field. With that wide angle lens, the gradations between 3 ft and infinity become progressively so small as to be meaningless.
Depth of field, as you know, also varies with focal length. this creates problems with, let's say a 50-300 mm zoom. How do you display that range? With old film era zooms the scale was fan shaped and more or less of the scale was visible because the lens barrel moved in and out with the zoom function. How do yu do that with some of these internal zoom lenses?
The real solution is for the camera manufacturers to make determining Hyperfocal Distance a software function. A calculator could be built in and displayed on the LCD screen. In fact, that wouldn't even be necessary. A simple press of a button would set the focus at the HFD for that lens at the selected zoom and f/stop all based on a generous print size. The camera body already knows what focal length lens is on the camera and can focus the lens to a predetermined distance as these are already a part of the Exif data.
Simple, huh!
quote=Darryl88 quote=Nikonian72 The colored-line... (
show quote)
Thanks birdpix - don't you just sometimes miss the old days with the fan shaped lines - no computers - just lines you could easily see....unfortunately I am still at a loss as to what the window is telling me.... :? Darryl
birdpix
Loc: South East Pennsylvania
Darryl88 wrote:
birdpix wrote:
Darryl88 wrote:
Nikonian72 wrote:
The colored-lines aperture scale on older lenses is used to set lens focus to the "hyper-focal distance", which is the lens position that captures "infinity" to near-focus in DOF, depending on the aperture selected. The smaller the aperture (larger number) the greater the DOF. Auto-focus will not achieve maximum hyper-focal DOF.
Basically, you manually set focus by positioning the infinity sign at the farthest colored line that corresponds to your chosen aperture. Every distance to the matching colored line will also be in focus.
The colored-lines aperture scale on older lenses i... (
show quote)
Hi Nikonian, thank you for the answer - I am aware of my aperture settings as regards my DOF. My problem is the lens doesn't have any of the coloured lines that represented your focal range (on the older lenses) - it only has one single white line in the middle of the window (the book refers to this as the 'Focus Index Line'). I am thinking maybe you use the window itself as your upper and lower focus points ie: whatever distance is in the window is all in focus. This window is probably only suitable for close up work because the range is only from .8ft~3ft and infinity. If I want to focus on something 30 feet away the whole window seems superfluous.
I wasn't aware that 'auto-focus' wont achieve maximum Hyper-focal DOF. Thanks for your help. Darryl
quote=Nikonian72 The colored-lines aperture scale... (
show quote)
No, you can't use the edge of the window itself as the range for determining the depth of field. With that wide angle lens, the gradations between 3 ft and infinity become progressively so small as to be meaningless.
Depth of field, as you know, also varies with focal length. this creates problems with, let's say a 50-300 mm zoom. How do you display that range? With old film era zooms the scale was fan shaped and more or less of the scale was visible because the lens barrel moved in and out with the zoom function. How do yu do that with some of these internal zoom lenses?
The real solution is for the camera manufacturers to make determining Hyperfocal Distance a software function. A calculator could be built in and displayed on the LCD screen. In fact, that wouldn't even be necessary. A simple press of a button would set the focus at the HFD for that lens at the selected zoom and f/stop all based on a generous print size. The camera body already knows what focal length lens is on the camera and can focus the lens to a predetermined distance as these are already a part of the Exif data.
Simple, huh!
quote=Darryl88 quote=Nikonian72 The colored-line... (
show quote)
Thanks birdpix - don't you just sometimes miss the old days with the fan shaped lines - no computers - just lines you could easily see....unfortunately I am still at a loss as to what the window is telling me.... :? Darryl
quote=birdpix quote=Darryl88 quote=Nikonian72 T... (
show quote)
Darrell, the only thing it is telling you is what distance the lens is focused at. With the 10-20mm between 3' and infinity it may be irrevelent.
Actually in the old days I depended on DOF preview instead of looking at lines on the lens barrel. But not all bodies have that feature and at small apertures it might be hard to see. I tend to get a "feel" for different lenses and pretty much know what my limits are with a particular lens at certain aperture settings. And with digital you can always see what you got and adjust and shoot over. Unless of course we're talking action, rapidly changing light, weddings, etc. etc. etc. LOL!
Birdpix:
Like your idea - wouldn't that feature reduce number of out-of-focus photographs being taken? Less wasted space of card, less paper used, less ink sold. Hum - maybe we need to get the conspiracy folks involved in this discussion. LOL
birdpix wrote:
Darryl88 wrote:
birdpix wrote:
Darryl88 wrote:
Nikonian72 wrote:
The colored-lines aperture scale on older lenses is used to set lens focus to the "hyper-focal distance", which is the lens position that captures "infinity" to near-focus in DOF, depending on the aperture selected. The smaller the aperture (larger number) the greater the DOF. Auto-focus will not achieve maximum hyper-focal DOF.
Basically, you manually set focus by positioning the infinity sign at the farthest colored line that corresponds to your chosen aperture. Every distance to the matching colored line will also be in focus.
The colored-lines aperture scale on older lenses i... (
show quote)
Hi Nikonian, thank you for the answer - I am aware of my aperture settings as regards my DOF. My problem is the lens doesn't have any of the coloured lines that represented your focal range (on the older lenses) - it only has one single white line in the middle of the window (the book refers to this as the 'Focus Index Line'). I am thinking maybe you use the window itself as your upper and lower focus points ie: whatever distance is in the window is all in focus. This window is probably only suitable for close up work because the range is only from .8ft~3ft and infinity. If I want to focus on something 30 feet away the whole window seems superfluous.
I wasn't aware that 'auto-focus' wont achieve maximum Hyper-focal DOF. Thanks for your help. Darryl
quote=Nikonian72 The colored-lines aperture scale... (
show quote)
No, you can't use the edge of the window itself as the range for determining the depth of field. With that wide angle lens, the gradations between 3 ft and infinity become progressively so small as to be meaningless.
Depth of field, as you know, also varies with focal length. this creates problems with, let's say a 50-300 mm zoom. How do you display that range? With old film era zooms the scale was fan shaped and more or less of the scale was visible because the lens barrel moved in and out with the zoom function. How do yu do that with some of these internal zoom lenses?
The real solution is for the camera manufacturers to make determining Hyperfocal Distance a software function. A calculator could be built in and displayed on the LCD screen. In fact, that wouldn't even be necessary. A simple press of a button would set the focus at the HFD for that lens at the selected zoom and f/stop all based on a generous print size. The camera body already knows what focal length lens is on the camera and can focus the lens to a predetermined distance as these are already a part of the Exif data.
Simple, huh!
quote=Darryl88 quote=Nikonian72 The colored-line... (
show quote)
Thanks birdpix - don't you just sometimes miss the old days with the fan shaped lines - no computers - just lines you could easily see....unfortunately I am still at a loss as to what the window is telling me.... :? Darryl
quote=birdpix quote=Darryl88 quote=Nikonian72 T... (
show quote)
Darrell, the only thing it is telling you is what distance the lens is focused at. With the 10-20mm between 3' and infinity it may be irrevelent.
quote=Darryl88 quote=birdpix quote=Darryl88 qu... (
show quote)
Yes, I think the whole window (on this lens) is as much use as tits on a bull. The DOF with this lens is so huge the window becomes superfluous. it's total range is only from .8'~3'~infinity. I don't really think I need a guage to tell me I am focusing at 2 feet! Thanks for your imput. Darryl
pounder35 wrote:
Actually in the old days I depended on DOF preview instead of looking at lines on the lens barrel. But not all bodies have that feature and at small apertures it might be hard to see. I tend to get a "feel" for different lenses and pretty much know what my limits are with a particular lens at certain aperture settings. And with digital you can always see what you got and adjust and shoot over. Unless of course we're talking action, rapidly changing light, weddings, etc. etc. etc. LOL!
"shoot over" ~ what, don't we all get the perfect shot first time :thumbup: :thumbup: Love your 'Thompson' quote btw.
Darryl88 wrote:
pounder35 wrote:
Actually in the old days I depended on DOF preview instead of looking at lines on the lens barrel. But not all bodies have that feature and at small apertures it might be hard to see. I tend to get a "feel" for different lenses and pretty much know what my limits are with a particular lens at certain aperture settings. And with digital you can always see what you got and adjust and shoot over. Unless of course we're talking action, rapidly changing light, weddings, etc. etc. etc. LOL!
"shoot over" ~ what, don't we all get the perfect shot first time :thumbup: :thumbup: Love your 'Thompson' quote btw.
quote=pounder35 Actually in the old days I depend... (
show quote)
I have a 'fridge magnet with the quote and a photo of Hunter on it. Gets a lot of laughs when I have company over for a cookout. And some strange looks from new guests who don't know me very well. :roll:
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