A77 EVF - Technical Question

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deathvalleydave
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A77 EVF - Technical Question

Unread post by deathvalleydave »

Regarding looking through the A77's EVF in a high dynamic range situation, am I correct in stating that the dynamic range you see in the EVF is exactly the same as the picture being taken in the A77? In other words do you see exactly what the final image will be (prior to any post processing) in the EVF, concerning dynamic range.

Reason I ask is because I never thought about stressing the EVF in this way, and initially thought of this as a negative quality of EVF's, but if it's exactly what you'll get in the picture you shoot, then I can see this being a positive in favor of EVF's.

Thanks for any technical input here...
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Re: A77 EVF - Technical Question

Unread post by David Kilpatrick »

No, not at all. There's a stack more shadow and highlight detail in any raw file, and generally quite a bit more visible in any JPEG file. The EVF is pretty contrasty and in order to get some idea of raw files, I use Standard with -3 contrast (EVF does 'reflect' your settings but it is always more contrasty than the final image).

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deathvalleydave
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Re: A77 EVF - Technical Question

Unread post by deathvalleydave »

So then, unfortunately, you don't see what you get in an EVF, other than a live histogram. But, you can get a live histogram with live view. I'm beginning to wonder what the real merits of an EVF are in fact, over the A900's OVF. I want to stay open minded, but this is possibly a deal breaker for me for future cameras - I would rather have a 100% OVF for the main reason that an OVF has infinite resolution and shows you what's really out there, rather than an EVF which is striving to approach that. Furthermore, now that I've found out that EVF's don't show you what you will get (something that I was going to use as an advantage for the EVF's), I'm starting to really wonder just how good my CZ 24-70 is now, as it is the main reason I've stuck with Sony so far - a great standard zoom. Although I'm somewhat "future-proofed" with my A900 and CZ 24-70, it's a bit sad to see that it will soon become an obsolete camera in Sony's mind, design wise - because if they are getting rid of OVF's for good, even in their A900 line, it will be the last Sony/Minolta classic camera. I'll probably never want to go the SLT route, so maybe they'll come out with a NEX 9, which can still use my CZ 24-70!
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Re: A77 EVF - Technical Question

Unread post by jcoffin »

While you have some point, I think it's also worth mentioning that on an EVF you can magnify parts of the picture. At least for those of us with limited eyesight, this can give an EVF greater effective resolution than an OVF (and, of course, you can do the same with live view). While my experience with it is quite limited, it seems to work well for slower-paced shooting, but is nearly useless for anything like sports. At the same time, I should add that an EVF seems to provide little advantage over live view in this respect.
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Re: A77 EVF - Technical Question

Unread post by David Kilpatrick »

Let's just say this - I was shooting with the 70-400mm doing tests indoors, and setting up micro AF adj on the A77 and A900. I was really surprised after the comfort and ease of using the A77 (by tungsten light, though I used flash for the exposures) how dim and difficult to 'visually focus check' the A900 was. The finder view appeared to be say eight times dimmer than the A77.

People forget this. No matter how horrible the light is, how dull, the EVF always has the same comfortable brightness. And if you use +/- correction, it shows the effect.

The point about the shadow and highlight detail is that the EVF is the WORST you can get. Your final image will always have more in reserve.

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mikeriach
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Re: A77 EVF - Technical Question

Unread post by mikeriach »

I'd be rather concerned if the jpeg I got resembled the EVF view. Fortunately by design it is significantly better.
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Re: A77 EVF - Technical Question

Unread post by agorabasta »

Their apparent unwillingness to correct the absolutely obvious issue with blown contrast in the EVF view really smacks of bad attitude. Even more so that there are quite a few good ways to do so. The easiest would be to add a contrast control to the liveview, globally - because I don't think they have the hardware capability to separately control the LCD and the EVF display through the firmware adjustments.

But the good and proper way would be to get a global contrast limiter to have the highlights/shadows to clip no more than 1% in the output. Because they have intentionally made the EVF/LCD more punchy just to attract simple souls. With the limiter they could achieve their goals without averting the good sophisticated users.
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Magnar Fjortoft
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Re: A77 EVF - Technical Question

Unread post by Magnar Fjortoft »

deathvalleydave wrote:Regarding looking through the A77's EVF in a high dynamic range situation, am I correct in stating that the dynamic range you see in the EVF is exactly the same as the picture being taken in the A77?
You don't see excactly the same dynamic range in the EVF as the final image. Still I find the EVF really helpful for determining if the exposure is well within the range of "correct" or indicated, or not. With an OVF you don't have a clue, except for looking at symbols that represent the exposure.

Just take an jpg image with the camera, and then display it in the viewfinder. The jpg file will show some more highlight and shadow detail than the live view. Actually I think the limited dynamic range of the viewfinder is to ensure high contrast, so that the display stays "bright and clear".

When learning the EVF to know, I find it really helpful also for judging the exposure. When learned the EVF to know, you soon know how to expose to avoid blown highlight detail, also for jpg files. The shadows are never a problem. They will just follow the exposure as deep as the dynamic range of the sensor can record data.

For most situations you don't have mental capasity to check the tonal range when consentrating on framing and timing, like you can't fine tune autofocus for fast moving subjects. If you could, manual focus wouldn't be any problem. Also, for critical work you have the live histogram and the option of making some brief test exposures to ensure the very best exposure.

Most files are post processed. Even jpg files are often fine tuned. So expecting the viewfinder to show the final result is a bit too optimistic, I think. At best the EVF would show the final result for an unprocessed or in-camera processed image, which is just a starting point for many serious photographers.

Totally, I find the EVF very useful for checking the exposure. Then you have all the other benefits of the EVF, like bright and clear in low light, virtual horizon, live histogram, focus peaking and mignified view on the fly, etc. etc.
deathvalleydave
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Re: A77 EVF - Technical Question

Unread post by deathvalleydave »

Thanks for the input on the EVF. I totally understand that we all post process to different degrees, but I thought maybe the EVF represented a "RAW" type representation or unprocessed jpeg representation of the picture being taken in 'real time' - but it looks to be apples and oranges between EVF and final image, with caveat that EVF may be a closer representation of the final image prior to post processing?

Plus, how could I even think it could pull this off? Because wouldn't it increase buffer times or EVF lag times, to be able to continually refresh the EVF with what the final image would be almost instantaneously speaking - what type of super processor would the camera need? How does Live View work in this regard - is it the same in that Live View also doesn't represent the final image either - it's just a larger EVF that's layed out flat on the back of the camera?

I really want to keep an open mind to all this...
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Magnar Fjortoft
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Re: A77 EVF - Technical Question

Unread post by Magnar Fjortoft »

deathvalleydave wrote: I totally understand that we all post process to different degrees, but I thought maybe the EVF represented a "RAW" type representation or unprocessed jpeg representation of the picture being taken in 'real time' - but it looks to be apples and oranges between EVF and final image, with caveat that EVF may be a closer representation of the final image prior to post processing?
The evf is what a lot of serious videomakers have used for many years, and for critical work they have added an external monitor. When stills and video is merging, the ovf is dead.
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Dusty
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Re: A77 EVF - Technical Question

Unread post by Dusty »

Magnar Fjortoft wrote: The evf is what a lot of serious videomakers have used for many years, and for critical work they have added an external monitor. When stills and video is merging, the ovf is dead.
And this is the problem for stills shooters who don't want video. Where do we go for a DSLR that NOT a DSLR/VR?

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Magnar Fjortoft
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Re: A77 EVF - Technical Question

Unread post by Magnar Fjortoft »

Dusty wrote:
Magnar Fjortoft wrote: And this is the problem for stills shooters who don't want video. Where do we go for a DSLR that NOT a DSLR/VR?
As a stills photographer I am trying to adopt, and from what I have seen I do not worry about the future evf technology.

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