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View Full Version : Exposure simulation through viewfinder??



nico
06-07-2011, 1:33pm
Hey all,

I'm wodering if any Canon DSLR's have exposure simulation through the viewfinder, or whether this feature is only in Live View mode as per my 60D? What I mean by exposure simulation is that the viewfider gets darker / lighter depending on aperture / shutter speed adjustments.

I think this would be an extremely useful feature to take the guesswork out of ensuring correct exposure (I hate shooting Live View unless absolutely necassary).

Thanks!

ricktas
06-07-2011, 1:39pm
Which Canon? Features vary between models.

andylo
06-07-2011, 1:41pm
There is a Depth of View preview button for the Canon bodies. Most of them is a small one near the lens (not be mistaken by the lens release button) Press and hold on that and you should be able to see the exposure simulation you described thru the view finder.

kiwi
06-07-2011, 1:42pm
Im confused really, you only see through the viewfinder what you see with the naked eye dont you ?

The meter is there to help you with the exposure. Im not sure Id personally want an alternative electronically generated view and would prefer to use the LCD playback for that

nico
06-07-2011, 1:49pm
Which Canon? Features vary between models.

I have a 60D, which doesn't have the feature I'm asking about. Does any Canon DSLR (or any brand for that matter)?


There is a Depth of View preview button for the Canon bodies. Most of them is a small one near the lens (not be mistaken by the lens release button) Press and hold on that and you should be able to see the exposure simulation you described thru the view finder.

Yes, but my understanding is that the DOF preview button only simulates the selected aperture & doesnlt take shutter speed into account, so this isn't what I'm talking about.


Im confused really, you only see through the viewfinder what you see with the naked eye dont you ?

Yes, this is the case on my 60D. My question is is a simulated view available on other models??

William
06-07-2011, 2:04pm
NO, Not that I know of, I just have the DOF preview that Andy talked about, The 60D is the lastest offering so :confused013

nico
06-07-2011, 2:10pm
Hmmm. I swear my old Sony a330 had this feature...

kiwi
06-07-2011, 2:12pm
Im pretty certain its not a Nikon feature in any model either

Tannin
06-07-2011, 2:35pm
It is not sensibly possible to do this with a viewfinder. You can do it with a screen - this is how you can see it with live view, or through a point and shoot camera with an EVF instead of a real viewfinder. Just take the shot and chimp if you need to.

Scotty72
06-07-2011, 2:49pm
7D only via screen (exp simulator)

soulman
06-07-2011, 3:42pm
...my understanding is that the DOF preview button only simulates the selected aperture & doesnlt take shutter speed into account, so this isn't what I'm talking about.I can't see how shutter speed could possibly be simulated other than by giving you a 'frozen' view, which is not going to happen with an optical viewfinder. Surely it would be easiest to just make a test exposure if you need to?

arthurking83
06-07-2011, 3:45pm
What Tony says is the truth, the whole truth and nothing but the truth.. so help him.... <insert diety of choice here>

With an optical viewfinder, it's impossible to simulate every concievable exposure combination.... That is, from pure white to pure black.

I don't know of any Nikon cameras that do an exposure simulator mode via the review screen, but if you set a Canon camera(with this feature) to manual and set it up with certain parameters, does it give you a visual cue of the actual scene with the expected exposure?

That is, imagine a dimly lit scene at night that requires ISO100, 15s and f/2.8, for a good exposure, and you set the camera up with ISO1600 30s and f/1.4(which will be almost pure white by comparison).. does the image review screen display a pure white nothingness, or does it simply display the scene as best as it can, BUT with a massively over blown histogram indicator ?

The optical path through to an optical viewfinder is completely independent to the sensor/film plane, but I suppose could be made to indicate a possible exposure scenario. That would require a filtering and lighting system in the viewfinder to simulate how an exposure would turn out, which in turn would be based on what the metering system is reading. Too much complexity for no real gain tho.

nico
06-07-2011, 4:01pm
I can't see how shutter speed could possibly be simulated other than by giving you a 'frozen' view, which is not going to happen with an optical viewfinder. Surely it would be easiest to just make a test exposure if you need to?

I didn't expect anyone could explain the science of how this could work, that's for the egg-heads at the big manufacturers to work out!
:)
Imagine if you COULD look through the viewfinder, depress 1/2 way & see exactly how your shot will expose with the current shutter / aperture setting & you could adjust until you were happy. I reckon that would be sweet.

James T
06-07-2011, 4:06pm
I didn't expect anyone could explain the science of how this could work, that's for the egg-heads at the big manufacturers to work out!
:)
Imagine if you COULD look through the viewfinder, depress 1/2 way & see exactly how your shot will expose with the current shutter / aperture setting & you could adjust until you were happy. I reckon that would be sweet.

You may as well use liveview if you've got that much time.

Anyway, as said, not going to happen with an optical viewfinder.

To me it would be a nasty feature anyway, lots of time and effort goes into making viewfinders as bright as possible. They're for seeing through, making it darker means it's harder to focus, frame, interact with your subject.

Tannin
06-07-2011, 4:18pm
I didn't expect anyone could explain the science of how this could work, that's for the egg-heads at the big manufacturers to work out!

It already does work.

Perfectly, or pretty close to it. There is even a name for the thing you look though that does this: it's called an Electronic View Finder, or an EVF for short. Most photographers don't like them, but some cameras have them and they are becoming quite common these days, so it's easy enough to find one if that's what floats your boat.

You even have the ability to do this and still keep an actual viewfinder, via the magic of live view. At least on Canon cameras (not sure about other brands) you can set live view to show you exactly what you are getting. (There is a switch for it, I forget where.)

But if you want that in the viewfinder then it isn't a viewfinder anymore. Wishing for a viewfinder that does what you want is like wishing for a fish with a beak, wattles and feathers that can fly, lay eggs, and wake you up before sunrise. You can have one anytime you want, but most people will probably call it a chicken.

(Hint: if you want it to lay eggs and call before daybreak, you will probably need two of them.)

nico
06-07-2011, 4:52pm
They're for seeing through, making it darker means it's harder to focus, frame, interact with your subject.

It could also be brighter, depending on where you set your exposure. It would only be darker if you chose to under expose the shot considerably & you'd rarely chose to do that...


You even have the ability to do this and still keep an actual viewfinder, via the magic of live view. At least on Canon But if you want that in the viewfinder then it isn't a viewfinder anymore. Wishing for a viewfinder that does what you want is like wishing for a fish with a beak, wattles and feathers that can fly, lay eggs, and wake you up before sunrise. You can have one anytime you want, but most people will probably call it a chicken.

(Hint: if you want it to lay eggs and call before daybreak, you will probably need two of them.)

So you're saying that it's impossible for modern science? I find that hard to believe :rolleyes: I button similar to DOF preview where you could quickly check expoure before taking a shot surely wouldn't be too hard to implement.

James T
06-07-2011, 5:01pm
It could also be brighter, depending on where you set your exposure. It would only be darker if you chose to under expose the shot considerably & you'd rarely chose to do that...



So you're saying that it's impossible for modern science? I find that hard to believe :rolleyes: I button similar to DOF preview where you could quickly check expoure before taking a shot surely wouldn't be too hard to implement.

You can do that, as had been said, via an electronic viewfinder.

Theoretically maybe you could implement some system of variable ND filter somewhere in the pentaprism.. but that's a whole heap more calculations for the camera to do. And then if you dialled in a bright exposure, how do you expect that to be shown through an optical viewfinder? By amplifying the light coming through the lens? Oh, wait, that's an electronic viewfinder...:rolleyes:

It would have to show either as your eyes see it, or darker as with the DOF preview button stopping down the aperture.

Tannin
06-07-2011, 5:02pm
No. It has already been done and there is a name for it. It is called an EVF. most people don't like them, but if you want an EVF, go ahead and buy one. You can still call it a fish viewfinder if you want to.

Bennymiata
06-07-2011, 5:16pm
The Sony SLR's with the semi-transparent mirror have this feature, but the viewfinder is just a small, LCD screen.
Some point and shoot cameras like the new Fuji X-100 also have a projected image over the optical view, but I haven't heard of this in any SLR's.

Scotty72
06-07-2011, 5:20pm
If you want a screen then look at the screen; why would you want to put a screen in the viewfinder when you have a screen at the back?

Ms Monny
06-07-2011, 5:25pm
I have a 60D and YES IT DOES HAVE THAT BUTTON. It is on the left hand side (if you are looking at the camera front) and it is near where the lens screws on at about 1/2 way between 7 & 8 oclock. I dislike where they put this as it is a pain to hold down in that position. Okay if you use a tripod, but when hand holding, very very awkward.

BTW, I didn't read through the above posts due to lack of time, so I dont' know if the question has been answered yet.

Also, Magic Lantern books are amazing for learning about your camera. I bought the one for the 60D and I threw away the instruction book I got with the camera!! Its brilliant for loads of info, including this little button!!

Also, when you press it, it does help with showing whats in focus for the aperature you set BUT it does go darker because the aperature actually goes down to the one you set....so if you set it at f5, then less light is going to come in, hence the darker image on your screen. Does that make sense???

Tannin
06-07-2011, 5:34pm
BTW, I didn't read through the above posts

Funny you should say that. :)

fabian628
06-07-2011, 11:03pm
I have a 60D and YES IT DOES HAVE THAT BUTTON.

noooo :D thats dof preview button.

Ms Monny
07-07-2011, 8:23pm
OOPS!! :o :o :eek:

Yep, DOF preview button. I actually did read the posts after I wrote that but I still thought I was on the right track!

Was wondering why noone was saying YES! :lol:

arthurking83
07-07-2011, 9:31pm
......

So you're saying that it's impossible for modern science? I find that hard to believe :rolleyes: I button similar to DOF preview where you could quickly check expoure before taking a shot surely wouldn't be too hard to implement.

I think it would be extremely possible to do with today's current engineering knowledge... even on an optical viewfinder! There would be no requirement that the VF is of an electronic type.

To filter out ambient light only requires a filter that darkens the image. This part is easy and being small wouldn't add too much cost. A variable LCD filter should be easy and small enough to fit.

Conversely a company with an eye to weird engineering practises might also look at adding very bright light through to the vf so as to simulate an over exposure. Again, current technology is easy to add a small powerful LED source to blind the operator at will.. this is not some black magic engineering, it's simple and most likely very durable technology to operate. BUT the calibration of the two technologies is going to add complexity, bulk and weight, for what in the end would turn out to be a pretty useless and redundant technology(in the long term).
They(manufacturers) will all concentrate their efforts on super high quality EFV systems of some type over the next few years.

Remove the silly mirror and you have an extremely capable and near perfect camera system. In the future you will get what you want, but for now, the investment in such features would only futile.

ie. the most likely camera body types where this type of technology investment would pay itself off in a rapid manner are the high end bodies. The types of people that use higher end camera bodies are the types that want features that add sense of speed to their method of operation(or specific features that help with other annoying anomalies). Most of these people will have a basic understanding of how each exposure gradient will look in a particular scene, depending on how the camera is set up for the scene. (ie metering mode, colour being metered upon and so forth).
it woudl take one hell of an impressive program to differentiate the difference between a black colour being exposed at say -2Ev, as opposed to a white colour being exposed at -2Ev.
This is the calibration I'm referring too. To allow the camera to differentiate between a correctly exposed scene where the black metered at -2ev, as opposed to a potentially massive underexposure of -2Ev on a white patch requires human intelligence.
A contradiction of terms, I know, but a human can decide if they want their blacks at -2Ev and their 18% greys at 0Ev. A piece of silicon only sees degrees of exposure!
It doesn't know if you want that white to be black or the black to be white.

if you have an understanding of how exposure works, then you would see how the infinite variables of exposure require massive amounts of data processing, which is highly unlikely in any current camera body.

The hardware is technically easy, the software looks to be impossible the more I think about it.

you need to come to grips with what the meter indicator is actually trying to tell you, to understand the nature of what you're asking.

have you ever tried each and every possible metering permutation that your camera is capable of?

I think we may be needing a small how to and why is it so about metering.
if I get the time over the next week(holidays) I'll try to post one up.