Lawliet said:
jrista said:
I don't think you can have less lag than OVF...the lag in OVF is the response time of light itself moving through space. There is no digital processing involved at all...it's literally "real time". There is no lag imposed by the camera itself when using an OVF.
There is the Pulfrich-effect - the same variable delay in your visual system thats behind this also affects you while using an OVF. The light hits your retina with a bit of delay, but the nerve impulse caused by it arrives earlier at your brain if the EVF provides you with a stronger stimulus then the OVF. When you have higher ISOs or dark lenses then the OVF takes the second place in that race.
Your talking about the behavior of the human eye. That is external to the camera, and has nothing to do with ADDITIONAL lag imposed by the device. I'm talking about lag imposed by the camera itself...which is stacked on top of any other lag. Personally, when I use an EVF, I can FEEL the lag, every EVF I've tried so far is no where even remotely close to as responsive as an OVF. It isn't just lag, either...it's the way information on EVFs tend to render...there are pixel artifacts, column overlap (the same information gets written to neighboring columns during panning), etc. All of this creates a very displeasing effect and response when photographing action.
I also strongly dispute the notion that OVFs are poor for high ISO usage. I do astrophotography. Giving my eyes time to adjust, I can see and frame stars with the OVF extremely well. EVF? Live View? I'm lucky if I can see even one star because the noise levels of the screen are dictated by the sensor capabilities. I can see a lot of stars with my bare eyes and an OVF when framing for astro. Same goes for using an OVF in darker scenes...ZERO noise in the OVF. If you are shooting sports indoors, for example, it would be a simple matter of slapping on a pair of glasses, and lifting them up when looking through the viewfinder...your eyes would always be adjusted for the lower levels of light coming through the OVF. Same trick could be done for nighttime street photography, or any other low light photography (I've done that for shooting wildlife in the hour after sunset.) An EVF in these circumstances? Noise central!
msm said:
jrista said:
I don't think you can have less lag than OVF...the lag in OVF is the response time of light itself moving through space. There is no digital processing involved at all...it's literally "real time". There is no lag imposed by the camera itself when using an OVF.
The average response time may be 5ms, but my concern with EVFs is when the image processing pipeline that renders to the EVF screen gets bogged down. The A7r has one of the best EVFs on the market, and at it's best, it's response time is great. But it's still a limited system, and at worst, the A7r EVF stutters and tears like mad.
For me, EVFs have to achieve a worst case performance of say 5ms response before I think they could really be used for action photography.
EVF will always be more laggy than OVF. But is that really so important? More important than the 35-55ms minimum shutter lag (1DX numbers) in a DSLR because the mirror needs to move away before you can take pictures? With electronic shutters mirrorless cameras can totally beat that. I hope that we'll see mirrorless with electronic global shutter soon. But if it is true that the Samsung can do a full readout 240 times a second on the NX1 like they claim then they should already be able to make an electronic rolling shutter as fast as most mechanical FP shutters.
With electronic shutter there would be no mechanical parts limiting the frame rate either, so the readout speed is the limit, that means shooting at 30fps or faster should be no problem.
I'm not concerned about shutter lag. My biggest concern is when tracking in on a moving subject...say a bird or running deer....BEFORE starting my sequence of shots. The performance of the EVF in that lead time...and the follow up time after a burst and before the next...is where things usually fall apart. Any additional lag over and above the zero lag of an OVF can be at least "felt", if not seen. I could feel the lag with the A7s every single time I put my eye to the viewfinder. With lots of action, the processing pipeline that fed information to the EVF would start dropping data or get bogged down, resulting in stutter or tearing...both of which utterly decimate the whole entire experience.
There were some benefits...say real-time DOF preview, and maybe some focus assist features. But, in the end, I would happily give up any extra features just to have a viewfinder that responds instantaneously. My brain takes care of all the other biological effects Lawliet is trying to inject into the equation...those are completely beyond out control, and they are not apparent in my personal experiences with EVFs. It's the added layer of lag that an EVF imposes above and beyond the instantaneous response of an OVF, coupled with the rendering artifacts and other problems like stutter and tear that currently put my off of EVFs. They may someday solve all of these problems...and maybe the Samsung EVF is better than Sony's A7 line EVFs...but until I see some significant improvement overall, it's just a headache (literally...all those issues literally caused me a headach when I was using the A7r).