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Author Topic: A Redux Critique Of Contemporary Camera Design  (Read 7012 times)
Isaac
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« Reply #40 on: April 03, 2014, 09:05:22 PM »
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It's the atypical photographs where automatic features leave much to be desired.

Which makes the transition between AF and MF, and between MF and AF an important factor; because we'll want to make best use of what both offer.

I like the sound of this: "Direct manual focus (DMF) You can make fine adjustments manually after the focus is locked. You can quickly focus on a subject rather than using the manual focus from the beginning."
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wildlightphoto
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« Reply #41 on: April 03, 2014, 11:21:43 PM »
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The nature of the 'unprecedented' improvement in autofocusing includes both improved accuracy and improved 'efficiency of selection' of the precise focus point within the scene.

Oh! Ye person of little faith!  Grin

Can't use a camera that doesn't exist  Cheesy
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BJL
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« Reply #42 on: April 04, 2014, 09:54:25 AM »
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I like the sound of this: "Direct manual focus (DMF) You can make fine adjustments manually after the focus is locked. You can quickly focus on a subject rather than using the manual focus from the beginning."
Agreed: another of the considerations that many photographers would add to Ray's list is various aspects of ergonomics, and one good example is the ability to quickly and easily switch focus modes.  That "DMF" quote is from the description of a Sony camera, isn't it? It sounds similar to the various "AF+MF" modes of Olympus Micro Four Thirds cameras.  In fact, Olympus Four Thirds SLRs have also had it for a long time, but I prefer it with the option to have turning the focus ring also activate a magnified live view in the EVF.

I would like it even more if that magnified live view was in a window within a view that still shows the overall framing.  Which cameras, if any offer, that option?
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Isaac
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« Reply #43 on: April 04, 2014, 11:28:39 AM »
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That "DMF" quote is from the description of a Sony camera, isn't it?

I was trying to keep clear of the brand wars ;-) A7

Instead of AF or MF, how about a more dynamic focus control system that took MF actions as a directive to identify what AF should bring into focus: MF to AF to MF to AF…

I would like it even more if that magnified live view was in a window within a view that still shows the overall framing.  Which cameras, if any offer, that option?

Maybe…
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BJL
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« Reply #44 on: April 06, 2014, 03:03:08 PM »
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I was trying to keep clear of the brand wars ;-) A7
A worthy goal, and for all I know, all ILC systems have such an AF+MF mode these days --- though it might be easier to implement in lenses that use focus-by-wire, to avoiding the clash of manually turning a mechanically coupled focus ring one way while the AF motor is trying to move in the opposite direction.

Instead of AF or MF, how about a more dynamic focus control system that took MF actions as a directive to identify what AF should bring into focus: MF to AF to MF to AF…
I look forward to camera makers experimenting with ideas like that. At risk of heresy, I can see enhanced touch-screen controls being useful even when using the eye-level VF so that the touch-screen cannot be seen.
For example, one current camera [brand name suppressed to keep the peace] offers some ingredients that have potential for "manual selection of AF point", but they could work together far better than they currently do:
1. Select focus region (by touch on the rear screen, which only works when looking at that screen rather than using the eye-level VF)
2. zoom the preview to the selected focus region (by a preselected magnification factor; done with a press on one of the programmable buttons)
3. AF on the zoomed region (done with a half-press and hold of the shutter release). This can gives precise selection of a very small AF target if the maximum preview magnification is selected, generally making MF unnecessary if just slight camera movement is allowed to get the focus target right in the bull's-eye.
4. unzoom the preview, to check and fine-tune framing (done with another press on that programmable button)

But I struggle to use the current implementation of this, so I would like:
a. to be able to do step 1 with my eye to the VF, by "tracking" my finger over the rear touch-screen or with a touch pad in place of the four-way arrows
b. to adjust the degree of magnification at step 2 quickly on the fly, maybe with a touch-screen gesture or a slider
c. to avoid step 4, by the option of a "window-in-window" preview.
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wildlightphoto
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« Reply #45 on: April 06, 2014, 11:09:47 PM »
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A worthy goal, and for all I know, all ILC systems have such an AF+MF mode these days --- though it might be easier to implement in lenses that use focus-by-wire, to avoiding the clash of manually turning a mechanically coupled focus ring one way while the AF motor is trying to move in the opposite direction.
I look forward to camera makers experimenting with ideas like that. At risk of heresy, I can see enhanced touch-screen controls being useful even when using the eye-level VF so that the touch-screen cannot be seen.
For example, one current camera [brand name suppressed to keep the peace] offers some ingredients that have potential for "manual selection of AF point", but they could work together far better than they currently do:
1. Select focus region (by touch on the rear screen, which only works when looking at that screen rather than using the eye-level VF)
2. zoom the preview to the selected focus region (by a preselected magnification factor; done with a press on one of the programmable buttons)
3. AF on the zoomed region (done with a half-press and hold of the shutter release). This can gives precise selection of a very small AF target if the maximum preview magnification is selected, generally making MF unnecessary if just slight camera movement is allowed to get the focus target right in the bull's-eye.
4. unzoom the preview, to check and fine-tune framing (done with another press on that programmable button)

But I struggle to use the current implementation of this, so I would like:
a. to be able to do step 1 with my eye to the VF, by "tracking" my finger over the rear touch-screen or with a touch pad in place of the four-way arrows
b. to adjust the degree of magnification at step 2 quickly on the fly, maybe with a touch-screen gesture or a slider
c. to avoid step 4, by the option of a "window-in-window" preview.

Rube Goldberg comes to mind.
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BJL
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« Reply #46 on: April 07, 2014, 03:56:17 PM »
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Rube Goldberg comes to mind.
Maybe you were referring to this:


It does seem lately that there is a rush of potentially useful new technology being put into cameras before the designers have thought out the user interfaces needed to let photographers use the new stuff as they want to.
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wildlightphoto
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« Reply #47 on: April 07, 2014, 04:11:28 PM »
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Maybe you were referring to this:

 Grin

WRT focussing I don't grok why it must be so complicated.
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BJL
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« Reply #48 on: April 07, 2014, 08:13:11 PM »
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WRT focussing I don't grok why it must be so complicated.
Most of the time it is not so complicated: the one tough case that I often encounter is when I want to focus on an off-center point (so away from any traditional manual focusing aids) in a shallow DOF situation like close-up photography, and focus-and-recompose is unsatisfactory, perhaps because I am hand-holding. Then the un-magnified off-center image of any VF, optical or electronic, is not large or detailed enough for precise focusing, and traditional manual focusing tools like split images of micro-prism collars are not available, so I want magnification at a chosen off-center location.

Anyway, I can envison an inteface that makes it not at all complicated; hopefully smarter people than I will eventually get a simple solution into a camera.

Any suggestions?
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wildlightphoto
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« Reply #49 on: April 07, 2014, 10:14:20 PM »
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Most of the time it is not so complicated: the one tough case that I often encounter is when I want to focus on an off-center point (so away from any traditional manual focusing aids) in a shallow DOF situation like close-up photography, and focus-and-recompose is unsatisfactory, perhaps because I am hand-holding. Then the un-magnified off-center image of any VF, optical or electronic, is not large or detailed enough for precise focusing, and traditional manual focusing tools like split images of micro-prism collars are not available, so I want magnification at a chosen off-center location.

The situation you've described is one I also encounter often.  Before the multiple demands made of the light coming through the lens (i.e., light siphoned away from the viewing system for multi-pattern metering and AF systems) it was simple.  A large bright plain matte view screen like the Nikon F "E" screen or the Leicaflex SL's extremely fine micro prisms over the entire image area made this child's play.  This is 1960s technology.  Here's how the user focusses:

1) look through the viewfinder at the part of the image s/he wants to be in focus
2) turn the focussing ring until the desired image point has the highest contrast
3) there is no part three!

To put this kind of focussing system in a DSLR the camera maker would start by replacing the semi-silvered mirror with a fully-silvered mirror; this would make the viewfinder brighter so the viewscreen optimized for brightness (at the expense of focussing accuracy) could be replaced with one optimized for focussing accuracy.  The additional brightness resulting from the fully-silvered mirror also means the viewfinder magnification could be increased without reducing brightness to unacceptable levels.

This would mean no AF or multi-pattern metering.

I suggest that for many situations multi-pattern metering has outlived its peak usefulness because we can now review the histogram in near-real time.

I would further suggest that for many situations AF is a solution in search of a problem.  AF for landscapes?  Really?!?  It's not like the rocks & trees are going to run away.
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Isaac
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« Reply #50 on: April 08, 2014, 03:18:04 PM »
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…a solution in search of a problem.

My guess is that cameras are made for the vast majority of people who don't practice focusing their camera.


AF for landscapes?  Really?!?  It's not like the rocks & trees are going to run away.

The light runs away.

(Last week a beautiful rainbow appeared in perfect position over the motif and faded-away; to quickly for me to grab a camera, let alone focus.)
« Last Edit: April 08, 2014, 03:23:42 PM by Isaac » Logged
ErikKaffehr
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« Reply #51 on: April 08, 2014, 04:37:37 PM »
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Hi,

My experience is that AF is pretty exact for stationary subjects. On the other hand I prefer to use manual focus in magnified live view as soon as I have the camera on tripod and the subject is stationary.

One problem with AF is to choose the point focused on. There may be many options.

It seems that some users can focus very well using MF, but it got harder with modern view finders.

Best regards
Erik

My guess is that cameras are made for the vast majority of people who don't practice focusing their camera.


The light runs away.

(Last week a beautiful rainbow appeared in perfect position over the motif and faded-away; to quickly for me to grab a camera, let alone focus.)
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Ray
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« Reply #52 on: April 09, 2014, 11:49:06 AM »
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I can't see a major problem here when autofocusing with my Nikon D800E. There's an area outlined in the viewfinder, which is a bit smaller in size than a DX frame. Within that area one can choose a total of either 11 or 51 focus-point options which can be selected with one's thumb on the 'multiselector' dial on the back of the camera.

In other words, one can move a single focusing square to any of either 11 or 51 positions within a central area of the frame, as one looks through the viewfinder. Each press of the 'multiselector' dial moves the focusing square one position to the left or right, or to the top or bottom.

After moving the focusing square to the desired position within the composition, one can lock focusing with a single press of the AF-On button. No need even to keep one's thumb on the AF-On button. It's free to make other adjustments.

It should only be necessary to recompose (before pressing the shutter) if the desired focus point is close to an edge or corner of the frame, and even then, the degree of movement to recompose should not be significant, unless the desired focus point was in the very corner of the frame, which would be very unusual, especially considering that lenses are least sharp in the corner.
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Telecaster
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« Reply #53 on: April 09, 2014, 02:42:15 PM »
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It should only be necessary to recompose (before pressing the shutter) if the desired focus point is close to an edge or corner of the frame, and even then, the degree of movement to recompose should not be significant, unless the desired focus point was in the very corner of the frame, which would be very unusual, especially considering that lenses are least sharp in the corner.

Once you've used a camera that actually can focus precisely in the extreme corners you may discover that what looks like a lack of resolving capability is often just field curvature.

-Dave-
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ErikKaffehr
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« Reply #54 on: April 09, 2014, 03:05:30 PM »
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Hi,

I would agree on that point.

Best regards
Erik

Once you've used a camera that actually can focus precisely in the extreme corners you may discover that what looks like a lack of resolving capability is often just field curvature.

-Dave-
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BJL
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« Reply #55 on: April 09, 2014, 04:28:36 PM »
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The situation you've described is one I also encounter often.  Before the multiple demands made of the light coming through the lens (i.e., light siphoned away from the viewing system for multi-pattern metering and AF systems) it was simple.  A large bright plain matte view screen like the Nikon F "E" screen or the Leicaflex SL's extremely fine micro prisms over the entire image area made this child's play.  This is 1960s technology.  Here's how the user focusses:

1) look through the viewfinder at the part of the image s/he wants to be in focus
2) turn the focussing ring until the desired image point has the highest contrast
3) there is no part three!
...
This would mean no AF or multi-pattern metering.
That sounds like a nice option for some photographers, at least those (1) working with a camera that has a large enough format and a lens of large enough maximum aperture to provide a sufficiently bright and detailed OVF image [I suspect 35mm and up, and either primes of fast zooms], and (2) who never need AF, or can carry another camera for that need.  (No comment on multi-pattern metering, since I haven't used that for years.)

I can see that working for you (as shown by your great bird photos!), but hopefully you can see that it is not for all of us. My priorities run to having a single system camera with a combination of compactness and telephoto reach (and price) that rules out formats of 35mm or up.

I have some concerns though:
1) The resolution of the scattered secondary image in an SLR's OVF is far less than that of the sensor (~2MP?) so when shooting at close to maximum aperture, I doubt that any OVF manual focusing could be very precise.
2) At large apertures, about f/2 and beyond, the  secondary image in an SLR's OVF image has more DOF than the actual recorded image, so reliably precise MF with an OVF seems impossible.
3) How good is this when focusing off-center with the extremely shallow DOF of extreme close-ups?
« Last Edit: April 09, 2014, 04:41:52 PM by BJL » Logged
BJL
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« Reply #56 on: April 09, 2014, 04:41:11 PM »
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In other words, one can move a single focusing square to any of either 11 or 51 positions within a central area of the frame, as one looks through the viewfinder. Each press of the 'multiselector' dial moves the focusing square one position to the left or right, or to the top or bottom.
That sounds like up to about a dozen arrow button pushes to navigate between the "mere" 51 AF points that even state-of-the-art reflex system PDAF is limited to. For speed, I would prefer a single touch or quick glide across the rear touch-screen to select the AF point, along with the hundreds of AF points potentially possible with in-sensor AF and/or the complete flexibility in choosing the region to zoom in on in the EVF.  And I suspect that wildlightphoto would prefer the even faster focus point selection method of doing it with his eye and then watching that point as he turns the focus dial.


P. S. We have a lot of "this works well enough for my usage, so it should be good enough for every competent photographer" posts lately.
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wildlightphoto
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« Reply #57 on: April 09, 2014, 05:06:33 PM »
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It should only be necessary to recompose (before pressing the shutter) if the desired focus point is close to an edge or corner of the frame, and even then, the degree of movement to recompose should not be significant, unless the desired focus point was in the very corner of the frame, which would be very unusual, especially considering that lenses are least sharp in the corner.

This is cropped from the corner of the image:


where my lens is plenty sharp at full aperture.  It's the Leica 280mm f/4 APO-Telyt-R.

According to Canon, focus-lock-recompose is unreliable at close range with shallow DOF, and my experience confirms it.  Along with the geometric inaccuracy caused by moving the image plane (or curved field, depending on the lens) which can be debated endlessly, subjects move in the time it takes to re-compose.



I have some concerns though:
1) The resolution of the scattered secondary image in an SLR's OVF is far less than that of the sensor (~2MP?) so when shooting at close to maximum aperture, I doubt that any OVF manual focusing could be very precise.

Accurate manual focus does not depend on the resolution of the screen.  Human eyes are much more sensitive to contrast than to detail, so the easiest way to focus is to maximize contrast at the point(s) you want to be in focus.  Nikon's "E" screen was great for this because the grid lines provided a reference point of maximum black.

Quote
2) At large apertures, about f/2 and beyond, the  secondary image in an SLR's OVF image has more DOF than the actual recorded image, so reliably precise MF with an OVF seems impossible.

That depends on the viewscreen.  The viewscreen you've described is typical of AF cameras, optimized for brightness at the expense of focussing accuracy.

Quote
3) How good is this when focusing off-center with the extremely shallow DOF of extreme close-ups?

See falcon photo above.  It would not have been easy keeping the eyes within a field of focus points.

Another benefit of being able to evaluate focus anywhere on the viewscreen is the ability to evaluate focus simultaneously in several regions of the picture.  While photographing this Mountain Bluebird I was able to maneuver so that not only is the eye in the plane of focus but much of the bird's back is also in focus - and I could see this in the viewfinder.

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BJL
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« Reply #58 on: April 09, 2014, 06:59:26 PM »
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Doug,
    I am definitely with you on the inadequacy of auto-focus, at least as it exists today, to choose focus on small off-center details in a scene like a bird's eye or a particular part of a botanical close-up.  With single point AF, it can be impractical to keep such a detail under a single selected AF point with a hand-held camera or a moving subject; with multi-point AF, the focus point is basically chosen as the part of the scene that is closest to the camera, which is not always where I want the focus to be!

Also, I had not thought of the fact that human focusing of an SLR (away from a central split image focusing aid) is basically contrast detect.  That motivates me to experiment more with how CDAF compares to manual focus on off-center subjects.
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Ray
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« Reply #59 on: April 09, 2014, 09:25:56 PM »
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That sounds like up to about a dozen arrow button pushes to navigate between the "mere" 51 AF points that even state-of-the-art reflex system PDAF is limited to. For speed, I would prefer a single touch or quick glide across the rear touch-screen to select the AF point, along with the hundreds of AF points potentially possible with in-sensor AF and/or the complete flexibility in choosing the region to zoom in on in the EVF.  And I suspect that wildlightphoto would prefer the even faster focus point selection method of doing it with his eye and then watching that point as he turns the focus dial.


P. S. We have a lot of "this works well enough for my usage, so it should be good enough for every competent photographer" posts lately.

I see that I should have provided more details. Whilst a single, brief press of the multiselector dial moves the focus square just one position, holding one's thumb on the dial causes the square to zip across the screen in a fraction of a second, but at a speed which is not too fast to avoid overshoot, with a bit of practice.

There is also a 'wrap around' option in the menu which, when enabled, allows one to move the focusing square in a single jump  from one extreme edge of the outlined frame to the opposite edge. Since the focusing square always remains in the same position it was last placed , this 'wrap around' feature can be useful when the following shot requires a focus point near the opposite edge to the previous shot.

Hope I've managed to clarify that.  Wink
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