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 p.5 #13 · Alt forum Nikon Z resource, discussion and image thread | |
zhangyue wrote:
I personal don't think there is any doubt that Z7 EVF is superior now. DPREVIEW stuff mentioned it and Multiple initial feedbacks from first hand review also confirmed it. Even there are many current MILC used this 3.69M EVF, they were not implemented the same way either in optics or electronics.
I believe the A7RIII low resolution during shooting is true based on all discuss linked in this thread from DPREVIEW discuss.
People also complained that x5 is blurred (based on low resolution version I guess) and only x10 give full resolution review during magnified shooting. (I even believe this is related to Nikon Z7 low battery rating for CIPA because of high resolution live feed EVF ).
Again, I don't know exactly how Sony implement this. However, 42M sensor only take raw data, LV implementation is like video feed that require either downsample the raw data and do the JPEG(or other picture format) feed at 60/120fps, or they just sample low resolution raw data from sensor directly and convert to JPEG feed,(most likely this way IMO) Either way, this low resolution mode will reduced process load and save battery power.
3.69M EVF at full resolution is about 1280X960 and at full 120FPS(for A7RIII spec) will give about 150M/s. It is not a light load by any means especially during shooting.
I really want to see how Canon R implement this. I also wonder about how FUJI and Leica Q&SL did this. ...Show more →
But Michael, I think you are mixing up full resolution here in your discussion. The way the Sony EVFs all work is that you can get the full resolution of the sensor read out at the highest level of magnification. In use, the highest level of magnification is thus an excellent representation of what the 100% view will look like on the computer after the shot is taken. If you think about it 3.69 MP is of course way too few to project the whole image of any mirrorless camera without downscaling, but if you only present a small part of the image (as when you magnify) then 3.69 MP is enough to present it at the full resolution of the sensor. So, with Sony's what you get is when shooting one type of downscaling, when doing the mid-level magnification a second sort of downscaling, and at full magnification you get the full resolution of the sensor. Because with full magnification you get the full resolution of the sensor I think we can rule out that they sample low resolution data to convert to JPEG, because they have full sensor resolution at full magnification. One thing that is definitely true about the existing Sony models is that the downscaling especially at moderate magnification does not always result in the same quality of image. Sometimes this downscaling clearly works better than others. For example, I think the A9 moderate magnification works a lot better than my Sony A7r II.
Now what does this mean for the Nikon Z7? First we know that you can not present a 45MP image at full resolution onto a 3.69MP EVF, so whatever people are saying at DPreview, the Z7 will not be presenting the full resolution of the sensor onto the EVF when in shooting mode. Neither will they be doing so at moderate levels of magnification. I do hope they have a mode where at the highest levels of magnification they will be presenting the full resolution of the sensor, like Sony does, and I expect they will have that sort of magnification.
The question that remains is how good is the video feed between the Sony A7r III and the Nikon Z7 in shooting mode and at moderate levels of magnification. This will be determined by at least two major factors. The way each company does the downscaling that they will both do, and how good are the optics in the EVF. We don't know anything about how that comparison will come out and this talk about the Nikon Z7 presents the image at full resolution and the Sony doesn't is not helpful. What may (and I stress may be the case) is the Nikon downscales the sensor image to 3.69 MP whereas Sony downscales to some multiple of 3.69 MP (say 1.845MP) and doubles the images to fill the EVF. That would mean that the Nikon present the shooting image at full resolution of the EVF (but certainly not full resolution of the sensor) and the Sony only presents the image at (half resolution of the EVF and is doubling the image in the EVF). I think that is highly unlikely, however, I think what is much more likely is that both Nikon and Sony downscale the data from the sensor to 3.69 MP and they just do so in different ways. Now the Nikon might present a clearer image in this downscaling but that might not be the case either. The Sony could even be better. Until the cameras are available we just can't know and we can't even compare specs unless the companies start to give specs on how they downscale and what exactly they use as the video feed to their EVF. And even if one company (say Nikon) chooses a video downscaling that emphasizes clearer resolution, that choice will come with tradeoffs. Such a downscaling will likely mean more lag between shots and perhaps a lower refresh rate. Some might prefer the downscaling that emphasizes resolution of the image and some might very well prefer the smoother rendering and short black out of a different downscaling approach that does not emphasize resolution so much but that allows a faster refresh rate and a shorter blackout. Of course the optics in the viewfinders are going to affect the apparent resolution of each viewfinder as well.
So, IMO, this talk about the Nikon Z7 being at full resolution and the Sony A7r III not being at full resolution is just way more confusing than it is helpful. First, it has to be completely wrong if we are talking about full resolution of the sensor. Second, it is likely (and I think very likely wrong) if we are talking about full resolution of the EVF. Third, what really matters is how the downscaling was done and what tradeoffs that requires and how good the optics are in the EVF. In short what does the image look like in the EVF and that we will know soon enough when the cameras can be compared side by side. The Nikon Z7 may well have superior optics, but I am not sure of that. I am pretty sure that whatever is done with the downscaling, however, will have tradeoffs. My best guess right now is that the Nikon Z7 will have downscaling that makes the image look sharper, but that will come at the cost of a lower refresh rate and a longer black out time between images than the Sony A7r III. Now is that a superior viewfinder? To some people it would be--in fact it would be for me--but I think there are lots of people that would prefer the Sony approach--and Michael I would not be surprised if that were you because you hate blackout between images. So, I think it will ultimately be more useful to talk about the tradeoffs in the viewfinder between Sony and Nikon and less useful to talk simply about one being superior and the other inferior.
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