Rick Posted July 4, 2013 Share #121 Posted July 4, 2013 Advertisement (gone after registration) So how do ou call the motion blur you see in your EVF my friend? I'm not the first one to call it this way am i? I seem to recall that Sean Reid called it the same way in his review of the M240. Anyway there is some blur in the finder image when the camera or the subject matter moves and this is due to the slow frame rate of the M240 so that replacing the EVF won't change anything to that i'm afraid. Ok, first of all I don't go by experts (Sean, Marc, etc...) as you know. I want to understand things myself. Ok, mjh is an exception. When I disagree with him I work it through until I agree with him. People here are talking about smearing and motion blur and frame rate and shutter speed and electronic frame rate and ... Let's make sure we are on the same page. Motion blur can only happen when motion causes blur during the time the shutter is open, electronic or mechanical. Next, the EVF has a refresh rate that is expressed in frequency or frames per second, not shutter speed. Shutter speed is how long the frame is exposed. Frame rate is how many of those frames are displayed per second. If you choose to expose the frame at 1/15 of a second, you will appreciate that any moving subject will seem blurred = motion blur. That is still photography. Video takes that frame blurry frame, shot at 1/15 sec, and flashes it 30 per second in the EVF of the M. So, you are going to see a blurry image 30 times in one second. The next sec on, it it going to show you another blurry image 30/sec. You can refresh that blurry frame 60/sec and it will still look just exactly as blurry. So, Frame Rate is independent of Motion Blur. More to come.... Link to post Share on other sites More sharing options...
Advertisement Posted July 4, 2013 Posted July 4, 2013 Hi Rick, Take a look here Will Leica update to the VF-4 EVF?. I'm sure you'll find what you were looking for!
Jeff S Posted July 4, 2013 Share #122 Posted July 4, 2013 Why the confusion? Aren't we talking about two different motion blurs? No, we're just talking about EVF blur. But we are talking about 2 different shutter speed concepts, only one of which is relevant to the discussion. Jeff Link to post Share on other sites More sharing options...
Rick Posted July 4, 2013 Share #123 Posted July 4, 2013 Film Movies are shot at 24 frames per second. Don't loose me here, most do. That is frame rate. That is how many times an image is flashed on the screen. That could be a blurry image just flashed 24 times. But, the magic of film movies is that if, the image is clear and without any motion blur, the eye sees 24 frames/sec as smooth. Most people don't see the jerky motion of 24 frames/sec. 180 degree shutter. What is that? That is the shutter in film movie cameras. This type of shutter exposes each film frame at 1/48 sec. Even though the display playback in the movie theater is showing you 24 frames/sec, the image looks clear because, 1/48 sec shutter speed stops most motion blur. If, the cinematographer doesn't pan too fast or shoot sports, the individual frames show no motion blur and therefore look clear. And, we know that 24 frames/sec refresh rate seems smooth to the human eye. More to come.... Link to post Share on other sites More sharing options...
AlanG Posted July 4, 2013 Share #124 Posted July 4, 2013 Video takes that frame blurry frame, shot at 1/15 sec, and flashes it 30 per second in the EVF of the M. So, you are going to see a blurry image 30 times in one second. The next sec on, it it going to show you another blurry image 30/sec. You can refresh that blurry frame 60/sec and it will still look just exactly as blurry. So, Frame Rate is independent of Motion Blur. More to come.... You can't shoot 30 fps with exposure times of 1/15 of a second or have an EVF work that way. Typical shutter speeds for 30 fps are around 1/60th. I have no idea what this EVF uses but with film and video if the shutter speed is too brief motion will be sharp frame to frame but can look choppy when played back. It may be counter intuitive but having some motion blur on each frame can make motion look smoother. So presumably this same issue will occur with an EVF if the shutter speed is too brief for the frame rate. When you shoot at 60 fps you will want to shorten the shutter speed to around 1/125. I am sure that camera manufacturers consider all of this when determining the relationship between light levels, frame rate, and shutter speed on the live view EVF image. The problem is that the Olympus VF-2 is pretty old technology so there are probably hardware factors that limit what it can do. It would be pretty sad to think that a new camera would not be able to get the most out of that EVF. It remains to be seen if the M and X-Vario have the hardware to get the most out of the VF-4. Link to post Share on other sites More sharing options...
Rick Posted July 4, 2013 Share #125 Posted July 4, 2013 Ok, so we get our new M and put the EVF on and pan around and what do we see. We see blur as we move the camera. But, let's be careful with the term blur. Everybody set their camera on the dreaded auto iso. Let the iso run to 3200. set the f-stop wide open. Set the shutter to A. Go outside and look through the EVF. On a bright day the motion in the EVF as you swing the camera back and forth will seem jerky. This is NOT motion blur. This is the result of 30 frames/sec refresh rate. Next, stop down to f 16. As you stop down the image will become blurry as you swing the camera back and forth. This is image blur. some have described it as smear, but let's stick with motion blur. This looks totally different than the jerky image in the first example. This motion blur that you see in the second example is dependent on shutter speed not refresh rate.... Link to post Share on other sites More sharing options...
Rick Posted July 4, 2013 Share #126 Posted July 4, 2013 Alan - Correct. (Ignore Alan for now, I'll get to that) Ok, so in the previous post we did not change the refresh rate of the view finder. It is made to obediently display 30 frames/sec no matter what those frames look like. so, what changed? The shutter speed changed. As you decreased the aperture in the second example, the camera (not you) had to choose a longer shutter speed to compensate for the smaller aperture. It was the slower shutter speed that caused the motion blur, not the frame rate. So, your M camera was choosing a shutter speed of maybe 1/10 sec to capture each frame. each frame was displayed 30 times each second in the EVF display. That is the blur you see. That kind of blur is motion blur and it is shutter speed dependent. Jello blur and jerky motion blur... Link to post Share on other sites More sharing options...
Rick Posted July 4, 2013 Share #127 Posted July 4, 2013 Advertisement (gone after registration) A new 60 fps Olympus viewfinder. I'm getting ahead of myself here. Hang on. Ok, what happen when you take your M and go out of A-mode and choose your own mechanical/manual shutter speed? Shouldn't this make the motion blur less? The answer is... No. This only changes the exposure of the still frame of the photograph you are trying to take. The video display ignores this and alters the electronic shutter speed based on its own algorithm. You may choose 1/90 sec and expect to see less motion blur in the EVF, but you won't. You will only see less motion blur in your actual photograph. That is why lct couldn't see any change in motion blur in his EVF when he changed the shutter speed manually. Olympus EVF... Link to post Share on other sites More sharing options...
Rick Posted July 4, 2013 Share #128 Posted July 4, 2013 Ok, so we all buy our new Olympus EVF. Is it going to be better and how? Well, it is going to display more images per second. But, those images (frames) are going to be dependent on a couple of things. First, they are going to be dependent on how many frames the camera sensor is sending the EVF display per second. From what Michael tells us, the sensor can only read out 30fps. So, the display can take those 30 frames from the sensor and display them 60/sec. But that doesn't gain us much. It might make the display look more solid and less flickery because our eye can't detect the flicker rate as easily. In other words the display screen may be less fatiguing and look more solid. Small, but nice gain in making the display itself look a little better. The display will have higher resolution and I understand it is larger. This is huge. The display is going to be able to better utilize the resolution of the sensor and display a much crisper image. This should be a huge increase in in fidelity. For the reason of higher display refresh rate (60 frames/sec) and a higher resolution panel, I will buy a new EVF. This is going to look really good. But, it won't help motion blur on the M... Link to post Share on other sites More sharing options...
Rick Posted July 4, 2013 Share #129 Posted July 4, 2013 The M is going to be stuck at 30 frames/sec refresh rate. This will look fantastic as long as you don't have anything moving too fast in your frame. But, as soon as you pan you are going to see jerky motion from the 30 frames/sec refresh rate, just like the current EVF. And, you are going to see motion blur in dim lighting - which means you are in dim lighting or have stopped down and forced the video algorithm in your M to choose a slower electronic shutter speed, which causes motion blur. But, if you can keep the M video EVF from choosing a slow shutter speed by taking pictures in bright light, or opening the aperture up, or raising the ISO, then the motion blur will be absent and you will only be subject to the somewhat jerky image displayed of 1/30 sec frame refresh rate inherent to the readout of the M sensor. But, for most things the display should be glorious. Link to post Share on other sites More sharing options...
Rick Posted July 4, 2013 Share #130 Posted July 4, 2013 One correction. In my examples I chose shutter speeds less than 1/30 sec. The M has a readout of 30fps, so the lowest electronic shutter is going to be 1/30 sec. But, the idea is that even at 1/30 sec, you will appreciate motion blur from a shutter speed of 1/30 sec. Link to post Share on other sites More sharing options...
lct Posted July 4, 2013 Share #131 Posted July 4, 2013 No offense intended, lct, but you also said that the issue had nothing to do with the shutter speed "you choose" (post #111)... And i confirm. It has indeed nothing to do with shutter speeds since it is completely independant from them. Link to post Share on other sites More sharing options...
mjh Posted July 4, 2013 Share #132 Posted July 4, 2013 And i confirm. It has indeed nothing to do with shutter speeds since it is completely independant from them. We are going ’round in circles it seems … Yes, the speed of the focal plane shutter that you set with the shutter dial has nothing to do with it. But why do you keep dragging it into the discussion then? We are talking about live view, after all, and during live view there is an electronic shutter (of the rolling shutter variety) at work, not the focal plane shutter. Its speed is controlled by the camera, independently of the shutter dial. Link to post Share on other sites More sharing options...
lct Posted July 4, 2013 Share #133 Posted July 4, 2013 You keep assigning me words i did not use mjh. For those interested, here's what Sean Reid wrote about the motion blur issue. There is a limitation, however, to using the M with electronic finders (rear screen or EVF) and that has to do with frame rate. The M is only able to feed the electronic finder at 30 frames per second. That wasn't an oversight on Leica's part, it's simply a technical limitation of the sensor/electronics pairing used in the M. As I've discussed many times in the past, however, 30 fps is slow enough to often cause motion blur in the finder image. This can happen when either the camera or the subject moves. Many current cameras are able to feed their electronic finders at 60 fps (and sometimes better). That difference tends to greatly reduce motion blur. Link to post Share on other sites More sharing options...
Jeff S Posted July 4, 2013 Share #134 Posted July 4, 2013 Who's on first comes to mind. Jeff Link to post Share on other sites More sharing options...
Karl G Posted July 4, 2013 Share #135 Posted July 4, 2013 Is this a case of beating the dead horses for courses? Link to post Share on other sites More sharing options...
jdlaing Posted July 4, 2013 Share #136 Posted July 4, 2013 Like this? Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/204418-will-leica-update-to-the-vf-4-evf/?do=findComment&comment=2366181'>More sharing options...
AlanG Posted July 4, 2013 Share #137 Posted July 4, 2013 My eyes have some motion blurring even when using an optical view finder. Link to post Share on other sites More sharing options...
k-hawinkler Posted July 4, 2013 Share #138 Posted July 4, 2013 My eyes have some motion blurring even when using an optical view finder. A Schnaps or two usually steadies the eyes and the hands! Now that motion blurring has been beaten to death, here is a picture of the OM-D E-M5's built in VF-2 and an external VF-4. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! One can see that the VF-4 is quite a bit larger and offers this performance at 60Hz: 2,360k-Pixel LCD Resolution, 1.48x Magnification & 100% Field of View. It offers a wonderful clear view but exhibits some digital artifacts that distinguish it from an OVF. For example, if one is panning across a fine detail, high contrast area aliasing is clearly visible. Nevertheless I find the VF-4 a wonderful tool and a joy to use. Now where is my M ready to be used with the VF-4? Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! One can see that the VF-4 is quite a bit larger and offers this performance at 60Hz: 2,360k-Pixel LCD Resolution, 1.48x Magnification & 100% Field of View. It offers a wonderful clear view but exhibits some digital artifacts that distinguish it from an OVF. For example, if one is panning across a fine detail, high contrast area aliasing is clearly visible. Nevertheless I find the VF-4 a wonderful tool and a joy to use. Now where is my M ready to be used with the VF-4? ' data-webShareUrl='https://www.l-camera-forum.com/topic/204418-will-leica-update-to-the-vf-4-evf/?do=findComment&comment=2366444'>More sharing options...
k-hawinkler Posted July 5, 2013 Share #139 Posted July 5, 2013 With regards to: "For example, if one is panning across a fine detail, high contrast area aliasing is clearly visible." I noticed this only for the VF-4 when the EVF Frame Rate was set to High and didn't see it when the EVF Frame Rate was set to Normal in my OM-D E-M5. Link to post Share on other sites More sharing options...
CheshireCat Posted July 5, 2013 Share #140 Posted July 5, 2013 And, we know that 24 frames/sec refresh rate seems smooth to the human eye. About this, it must be said that going up to 60 frames/sec, there is a great improvement. 24 frames/sec is just the bare minimum, and some humans will percieve a much more "natural" motion at 60 fps. Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.