Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: Peter_DL on April 04, 2010, 10:41:03 am
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It is a while ago that I’ve tried, and Sony was class-leading regarding Life View autofocus performance.
Did Canon or Nikon catch up in the meantime ?
Does it work now ?
Peter
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It is a while ago that I've tried, and Sony was class-leading regarding Life View autofocus performance.
Did Canon or Nikon catch up in the meantime ?
Does it work now ?
Peter
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Live view.
It has always worked. What is it you need it to do that it didn't?
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Live view.
It has always worked. What is it you need it to do that it didn't?
I guess that Peter was interested in the AF function of Live View. I can't say as my 1Ds3 doesn't provide AF when in Live View mode.
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It is a while ago that I’ve tried, and Sony was class-leading regarding Life View autofocus performance.
Did Canon or Nikon catch up in the meantime ?
Does it work now ?
As you know Sony's live view is done using a specific sensor of low resolution as opposed to Canon and Nikon using the actual sensor.
I rarely use AF lenses on my D3x these days, but as far as I remember the AF in live view mode is indeed very slow and probably only usable for static objects. It was very accurate though.
The reference for AF speed from actual sensor data is by far Panasonic with the GF1, they are in a class of their own. It is encouraging because it shows that with enough R&D focus it can be done.
Cheers,
Bernard
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I guess that Peter was interested in the AF function of Live View. I can't say as my 1Ds3 doesn't provide AF when in Live View mode.
Not at all? My 40D will not do contrast detect. It will flip up and do phase detect with the punch of the AF button.
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As you know Sony's live view is done using a specific sensor of low resolution as opposed to Canon and Nikon using the actual sensor.
I rarely use AF lenses on my D3x these days, but as far as I remember the AF in live view mode is indeed very slow and probably only usable for static objects...
Yes, that's what I meant.
Autofocus in live view mode felt unusable slow for many purposes, except with some Sony cameras.
Thanks for your comment on the D3x.
Peter
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Not at all? My 40D will not do contrast detect. It will flip up and do phase detect with the punch of the AF button.
The 1Ds Mark 3 has no AF in Live View. Its younger cousins are better equipped for that. To tell you the truth, it doesn't bother me at all but I understand that for some users it is a essential feature.
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As you know Sony's live view is done using a specific sensor of low resolution as opposed to Canon and Nikon using the actual sensor.
I rarely use AF lenses on my D3x these days, but as far as I remember the AF in live view mode is indeed very slow and probably only usable for static objects. It was very accurate though.
The reference for AF speed from actual sensor data is by far Panasonic with the GF1, they are in a class of their own. It is encouraging because it shows that with enough R&D focus it can be done.
Cheers,
Bernard
1) Sony's latest generation (Alpha 400, 500, 550) all have sensor-based liveview. The 500 and 550 also have the fast AF liveview mode you describe. Since the 450 is "old style" dSLR without the movable LCD and fast AF liveview, I think this bodes very well for all future Sony dSLRs of at least mid-high end featuring sensor-based liveview. Which is a good thing. . . I couldn't talk myself into buying an Alpha 850 because of the (stupid IMO!) lack of liveview.
2) The GF1 uses purpose-built contrast detect lenses, not legacy "phase detect" lenses. Not sure how fast the GF1 focuses with old-fashioned 4/3 lenses.
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1) Sony's latest generation (Alpha 400, 500, 550) all have sensor-based liveview. The 500 and 550 also have the fast AF liveview mode you describe. Since the 450 is "old style" dSLR without the movable LCD and fast AF liveview, I think this bodes very well for all future Sony dSLRs of at least mid-high end featuring sensor-based liveview. Which is a good thing. . . I couldn't talk myself into buying an Alpha 850 because of the (stupid IMO!) lack of liveview.
That's good to hear, since viewing/focusing off the actual sensor is the whole point for some of us, not being able to shoot hand-held as if using a point-n-shoot.
2) The GF1 uses purpose-built contrast detect lenses, not legacy "phase detect" lenses. Not sure how fast the GF1 focuses with old-fashioned 4/3 lenses.
I'm not sure what you mean by this, I don't think lenses are either phase-detect or contrast-based, as they don't actually focus themselves (although many have motors built-in). The camera decides what's in focus, either using phase-detect AF sensor (in the camera, not the lens), or using contrast-based AF in live-view mode (which works off the sensor and has nothing to do with the lens).
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I'm not sure what you mean by this, I don't think lenses are either phase-detect or contrast-based, as they don't actually focus themselves (although many have motors built-in).
True, but the different AF methods need quite different mechanical operation of the lens, and so favor different designs of the focussing elements and AF motors. As evidence, note that some newer 4/3 SLR lenses, designed with Live View in mind, work far better with Live View's CD AF than older 4/3 SLR lenses, and none of the high grade 4/3 SLR lenses with ring-style ("ultra-sonic") AF motors work at all well with CD AF. Panasonic m4/3 bodies do not bother to offer AF support for most 4/3 SLR lenses for some reason, and Olympus m4/3 bodies AF far better with its "CD AF friendly" lenses than with other 4/3 SLR lenses.
The issue I believe is that PD AF often needs just a single AF reading and then can (often, not always!) move the lens directly to the in-focus position, whereas CD AF requires repeated AF measurements in a feed-back loop, often requiring multiple start-stop movements, and often at least one reversal of direction. This favors designs with the lightest possible focusing element group, and motors of low mass and low rotational inertia (small moment of inertia). Sadly, the ring-style motors that give best PD AF performance might be poorly suited to CD AF, as they have a large diameter and so a large moment of inertia.
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There has been considerable discussion in this thread about live view and auto focus. Of course, I agree that better autofocus performance is a virtue. But as a landscape photographer, this hardly seems important at all. In my view, the use of live view and manual focus should "revolutionize" landscape photography. Maybe that is hyperbole and too strong, but live view permits the exploration of focus at nearly any point in the image. I can inspect focus with the lens stopped down, I can check depth of field. I don't have to rely on indirect focusing metrics, I turn the lens barrel and I can see my focus with the image enlarged 5x or 10x. This is the modern equivalent of the loupe and ground glass on a view camera. This also means that DOF charts are obsolete, replaced by direct inspection of the image field. Another important aspect of live view is that it permits a real-time histogram. So, the procedure is to compose, tweak the exposure with the real-time histogram, and then refine focus and check depth of field. Results show that this procedure yields more reliable and better control of both exposure and focus.
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... the different AF methods need quite different mechanical operation of the lens, and so favor different designs of the focussing elements and AF motors. As evidence, note that some newer 4/3 SLR lenses, designed with Live View in mind, work far better with Live View's CD AF than older 4/3 SLR lenses, and none of the high grade 4/3 SLR lenses with ring-style ("ultra-sonic") AF motors work at all well with CD AF. Panasonic m4/3 bodies do not bother to offer AF support for most 4/3 SLR lenses for some reason, and Olympus m4/3 bodies AF far better with its "CD AF friendly" lenses than with other 4/3 SLR lenses.
The issue I believe is that PD AF often needs just a single AF reading and then can (often, not always!) move the lens directly to the in-focus position, whereas CD AF requires repeated AF measurements in a feed-back loop, often requiring multiple start-stop movements, and often at least one reversal of direction. This favors designs with the lightest possible focusing element group, and motors of low mass and low rotational inertia (small moment of inertia). Sadly, the ring-style motors that give best PD AF performance might be poorly suited to CD AF, as they have a large diameter and so a large moment of inertia.
Interesting insights.
Many thanks!
Peter
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I tried it for the first time the other day my new 1d iv.
Works great.
Some observations.
- I agree with the comments regarding manual focus and landscape.
- Works a treat, especially with DOF and exposure tweaking.
- Although, i must say that when looking at the image on the screen and then swithcing it off and looking through the view finder, i found there were some instances where i got a better view in the finder, mainly when it was overcast and high glair.
- A black cover maybe necessary in the field during parts of the day.
- With AEB, it is great, if one sets the camera to show the exposure as it would be captured. This helps realy see the different exposure increments
I bought this camera for a variety of reasons. Autofocus was one, but i cant say i would use liveview when trying to track a kangaroo hopping towards me. I'll give it a go though!
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- Although, i must say that when looking at the image on the screen and then swithcing it off and looking through the view finder, i found there were some instances where i got a better view in the finder, mainly when it was overcast and high glair.
- A black cover maybe necessary in the field during parts of the day.
Here's (http://www.bhphotovideo.com/c/product/573167-REG/Hoodman_H_LPP3_HoodLoupe_Professional_LCD_Screen.html) the solution.
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Here's (http://www.bhphotovideo.com/c/product/573167-REG/Hoodman_H_LPP3_HoodLoupe_Professional_LCD_Screen.html) the solution.
Or here (http://www.photographybay.com/2009/02/11/faster-autofocus-for-canon-eos-dslr-live-view-mode/).
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Or here (http://www.photographybay.com/2009/02/11/faster-autofocus-for-canon-eos-dslr-live-view-mode/).
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I don't understand how that will help with glare on the LCD...
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Here's (http://www.bhphotovideo.com/c/product/573167-REG/Hoodman_H_LPP3_HoodLoupe_Professional_LCD_Screen.html) the solution.
I think I might buy one of those. Thanks for the info, Jeff.
What surprises me is that none of the reviews I've seen mention the advantage of easier manual focussing when that 'hoodloupe' is pressed to one's eye.
A high resolution, 920,000 pixel LCD screen with a 10x magnification provides a very accurate method of manual focussing, but not when the camera is held with two hands away from the face. There's too much movement.
However, with the hoodloupe it looks as though the camera can be held firmly at 3 points; the left hand on the lens for manual focussing, the right hand on the camera body, and the right eye pressed against the hoodloupe (which in turn is pressed against the LCD screen.
The reason I would be interested in the hoodloupe is not so much that I can avoid glare (although that's a clear advantage) but because I should be able to hold the camera more steady for manual focussing, when using LiveView.
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Ray, if you're talking about shooting hand-held with the camera up to your face, you might want to get the "cine" (http://www.bhphotovideo.com/c/product/658617-REG/Hoodman_HLCKIT_Cinema_Kit_HoodLoupe_3_0.html) version of the Hoodman Loupe, which allow you to strap the hoodman to the camera.
There are also higher-end viewfinders designed with shooting video in mind that may be of interest to you, such as the Zacuto (http://www.bhphotovideo.com/c/product/625808-REG/Zacuto_Z_FIND_Z_Finder_DSLR_Optical_Viewfinder.html).
Since I'm shooting from a tripod, I just wear the Hoodman around my neck on the included lanyard, and hold it up to the LCD when focusing.
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Ray, if you're talking about shooting hand-held with the camera up to your face, you might want to get the "cine" (http://www.bhphotovideo.com/c/product/658617-REG/Hoodman_HLCKIT_Cinema_Kit_HoodLoupe_3_0.html) version of the Hoodman Loupe, which allow you to strap the hoodman to the camera.
There are also higher-end viewfinders designed with shooting video in mind that may be of interest to you, such as the Zacuto (http://www.bhphotovideo.com/c/product/625808-REG/Zacuto_Z_FIND_Z_Finder_DSLR_Optical_Viewfinder.html).
Since I'm shooting from a tripod, I just wear the Hoodman around my neck on the included lanyard, and hold it up to the LCD when focusing.
I've purchase the cine version for use on the 40D and it works quite well. The loupe contains a magnifying lens that seems to over-magnify the LCD on the 40D so typically only the 5x magnification of the live-view is used. Use of the loupe allows the screen intensity to be turned down, saving both your eyes and the battery.
Alan
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Here's (http://www.bhphotovideo.com/c/product/573167-REG/Hoodman_H_LPP3_HoodLoupe_Professional_LCD_Screen.html) the solution.
That might be the best solution available so far.
What I hope for though is an accessory EVF that can be mounted on the hot shoe or elsewhere. It could work with the video out socket that many SLRs already have, or have a dedicated socket as on some Micro Four Thirds cameras. Such an EVF with a suitably long connecting cable could also be mounted away from the camera body when convenient, like when the camera is on a tripod in a position that makes it hard to put your eye behind it.
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That might be the best solution available so far.
What I hope for though is an accessory EVF that can be mounted on the hot shoe or elsewhere. It could work with the video out socket that many SLRs already have, or have a dedicated socket as on some Micro Four Thirds cameras. Such an EVF with a suitably long connecting cable could also be mounted away from the camera body when convenient, like when the camera is on a tripod in a position that makes it hard to put your eye behind it.
That would be an even more expensive solution, BJL. The Zacuto that Jeff referred to is much more expensve than the Hoodman Hoodloupes. Some of these devices have a magnifying capability which is really not necessary for the latest Canon cameras which have a 920,000 pixel LiveView screen and their own 10x magnification.
I get the impression that the 1D-Hoodman 3.0 Cinema Kit version is currently in the process of being upgraded. This is the version that most appeals to me. I've read reports of customer dissatisfaction with the method of attaching the Houdloupes to the camera body. I hope this is what is being upgraded.
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That would be an even more expensive solution.
About US$250 or less: that is the price of the Olympus VF-2 accessory EVF, which offers 800x600 resolution ("1.44MP" with that dodgy triple counting of pixels) vs the current maximum of 640x480 ("920,000") for rear screens. AFAIK, Epson makes the panel and it is available to other camera makers.
Given your camera gear buying habits, such as option does not seem horribly expensive, if it were available and useful to you!
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I don't understand how that will help with glare on the LCD...
I'm sorry if my post(s) was/were not clear enough !
I've always been talking about Autofocus-performace in Life-view mode.
Peter
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