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EVF image does not match actual shot


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yearningmaple

I'm new to my X-T1 and this forum, and am by no means a pro or even semi-pro photographer, so please bear with. Why is it that I can compose a shot in the EVF and it will look fairly well-exposed, certainly not any extremes on the histogram, yet the actual shot can come out totally black or virtually all blown out?

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I have no idea about setting my viewfinder to display actual exposure or standard brightness . . . Didn't know that was a thing.

That sounds like your problem then. You are shooting in Manaul exposure mode - how do you know the exposure is correct? If you have the EVF set to auto-gain, it will show a "correct" exposure regardless of what settings you choose manually. The histogram will also be "normal", but in no way reflect the actual shot you will take. Fortunately, Fuji eventually added the option in the menus so that the user can choose if they want the EVF to auto-gain, or to show the actual exposure. It sounds like it might be the problem - by default, auto gain will be turned on in the factory settings, I suspect.

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yearningmaple

To be more specific, it's Preview Exposure/WB in Manual Mode set to ON.

Doesn't that mean I should be able to preview the exposure when in manual mode? Which is exactly what I am not getting.

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There were a couple of strange M mode "features" in older Fuji cameras and this sounds like one of them. In my X-S1 the histogram in the M mode does not work: when you change the shutter speed or aperture, the histogram does not move. There is a little tick on the EV scale that moves up and down, but the histogram looks "normal" regardless of the camera settings.

So when in the M mode, do not trust the histogram, look at the position of the EV scale mark.

Unless this has been fixed...

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yearningmaple

What do you mean by "older" Fujis? I purchased this X-T1 summer 2014. My firmware is up to date as of 10 days ago approximately. Or are you referring to old models that are not X-T1? Thanks for your help.

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I'm curious about the EVF auto-gain setting, or concept. What is it? I've had my XT1 for a couple of months but have spent a lot of time trying to understand why the image taken is so much brighter than what's in the EVF. This appears after I've taken a few shots outdoors on a sunny day. The image looks fine in the EVF, then the result is overexposed by one or two stops. I finally took the camera in for service and they still have it.

If there's a setting I missed, I'd love to know. I'm assuming this is different than the 'exaggerated ISO' feature I've read about, which apparently causes slight underexposed of 1/3 stop. Feel free to correct me on this, I just recently read about it.

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The "exaggerated ISO" isn't really a "feature" - merely that for a stated ISO on the dial, the exposure you will get (shutter speed and aperture) can be up to 1EV more exposure than on other brands of camera at the same ISO. The Fuji exposure program / meter also tends to be rather generous by about 1/3-1/2EV so many people find they leave a little -ve exposure compensation dialled in.

As for the auto gain EVF, there is a menu item for it, but I can't tell you what it's called as I don't currently have a body with the feature. Maybe consult the manual, it will be in there somewhere. It's not called "auto gain" in the menu, more like something about preview exposure (sorry, really cant remember the name of the menu item).

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Thank you. If I understand correctly then the exaggerated ISO might account for my issue, where the image taken is quite a bit brighter than what appeared in the EVF? On my XT1 this made the images unusable, they were so overexposed. In LR I could reduce exposure by up to 2 stops to get them in the ballpark. I'm really hoping Fuji finds an issue that can be fixed.

Anyway thanks for replying, I'll look for that in the manual. It sounds a bit like "preview exposure in manual mode."

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Thank you. If I understand correctly then the exaggerated ISO might account for my issue, where the image taken is quite a bit brighter than what appeared in the EVF? On my XT1 this made the images unusable, they were so overexposed. In LR I could reduce exposure by up to 2 stops to get them in the ballpark. I'm really hoping Fuji finds an issue that can be fixed.

Anyway thanks for replying, I'll look for that in the manual. It sounds a bit like "preview exposure in manual mode."

No, the exaggerated ISO just means you get a slower shutter speed than you expect. So you think you are shooting at ISO1600 but really the camera has used an exposure suitable for ISO800, but you get a "normal" looking result.

The exposure programme is generous and tends to over-expose a bit too, so many dial in -1/3EV. They are 2 different issues.

If exposure preview is turned on, the EVF should give a reasonably accurate view of the exposure, as should the histogram. I think there may still be a bug when you use EV lock but the EVF doesn't reflect the locked exposure (not sure if yet fixed).

The other consideration is the EVF brightness, which is merely like turning up the brightness on your TV, it will make the EVF bright or dark, but not reflect the actual photo. Worth checking your brightness setting - but my guess is still that your exposure preview is turned off perhaps.

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Thanks again. I still need to think through ISO in these discussions.

I tried everything I could think of before bringing it in, resetting both menus to factory settings, re-applying the latest firmware, using my old camera to take the same images. Fingers crossed that they either fix it or send me a new camera. Sorry to hijack the thread!

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  • 2 weeks later...

I am a long time Canon shooter and a recent convert to Fuji. I discovered a strange quirk with the Fuji X-T1 and wanted to see if anyone else has experienced this... it sounds like it might be related to what is going on here, although my issue is one of underexposure.

Given, this is not a normal way to shoot, and I only discovered this by accident when the aperture ring got moved over to "A" without my noticing it. I was reviewing images and noticed they were all very underexposed while the viewfinder and histogram in the preview showed a correct exposure.

I found that if you manually set the ISO and shutter speed, but the aperture ring is in "A", then the camera (X-T1) will underexpose if the correct exposure of the scene is darker than your manually set ISO and shutter speed (and maximum aperture of the lens.) In this scenario, for some reason, the camera will show you an inaccurate histogram and viewfinder image that would lead you to believe it is going to be a correct exposure, yet the resulting image will be underexposed (by whatever degree your settings and the scene differ.)

This does not happen with overexposure in the same scenario, the camera will stop down the lens for a correct exposure.

In the samples below you can see what the screen and histogram show in the preview as a relatively "correct" exposure with highlights, shadows and midtones, but then the second image is of the review of the image after it is shot and you can see a 2 stop difference in the histogram.

The ISO and shutter were set manually, the aperture ring was on "A"

I was on the phone with Fuji this morning and they were able to replicate it and were also stumped as to why the camera would behave this way and have said they are going to forward this up the chain because it is not how the camera should behave in that situation.

Other details -

I do have the exposure preview set to on.

I haven't had any other exposure issues (other than those that were operator error ;-) )

I have been able to reliably replicate this with multiple bodies and different lenses.

The XT-1's all are using ver 3 firmware and my lenses have latest versions of firmware.

I am shooting raw and jpg. (The images (both jpg and raw) are in fact underexposed when you get them in Photoshop, Aperture, etc.)

Resetting the camera does not solve the problem.

I have gone through all the settings and can't find anything that is set improperly that would cause this strange quirk.

Obviously in this situation, there is no way the lens can open up more than its maximum aperture, and since the shutter speed and ISO are manually set, they won't change, but the camera should still reflect underexposure in the preview image in the viewfinder and in the histogram.

Has anyone else experienced this or figured out a fix?

Fuji said they would follow up with me when they have more info or a suggested course of action.

Screen preview of image (looks like a proper exposure)

Reviewing the same image after exposure shows a 2 stop underexposed image

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I found that if you manually set the ISO and shutter speed, but the aperture ring is in "A", then the camera (X-T1) will underexpose if the correct exposure of the scene is darker than your manually set ISO and shutter speed (and maximum aperture of the lens.) In this scenario, for some reason, the camera will show you an inaccurate histogram and viewfinder image that would lead you to believe it is going to be a correct exposure, yet the resulting image will be underexposed (by whatever degree your settings and the scene differ.)

...

The ISO and shutter were set manually, the aperture ring was on "A"

I was on the phone with Fuji this morning and they were able to replicate it and were also stumped as to why the camera would behave this way and have said they are going to forward this up the chain because it is not how the camera should behave in that situation.

Other details -

I do have the exposure preview set to on.

...

Obviously in this situation, there is no way the lens can open up more than its maximum aperture, and since the shutter speed and ISO are manually set, they won't change, but the camera should still reflect underexposure in the preview image in the viewfinder and in the histogram.

Firstly, your first point does not really make sense. If you have the aperture set to "A" then the camera will automatically adjust the exposure as it's exposure program decides. There is no "manually set" exposure since you have only set ISO and shutter,, so the camera is still free to adjust aperture as much as it can. This is shown as the aperture value in the viewfinder is red, I think indicating it is a value outside the cameras correct exposure program.

Under-exposure is being caused almost certainly because the camera cannot use a large enough aperture to get the correct exposure, given the ISO and shutter that you have fixed (it cannot change).

The EVF should show the "actual" exposure provided you have enabled that in the menus (and are not using exposure lock). However, I believe when the camera is unable to adjust the exposure to be "correct" (because in your case the aperture cannot be opened up large enough), I think it may just normalise to a standard brightness in the viewfinder. This is a guess as I don't have an X-T1, but knowing some of the other design issues/bugs that have previously existed with Fuji's implementation of the EVF (most now fixed), it would be my best guess).

The other option is that you have not actually turned on the menu option to make the EVF show the actual exposure, rather than an auto-gained normalised one (I'm afraid I still can't remember the name of the option - it's in the manual).

If you put the camera in full manual mode (set everything yourself), as you adjust the exposure (e.g. vary the shutter speed up and down) you should be able to check if the EVF is reflecting the actual exposure, and the circumstances in which it ceases to do so. I am pretty sure it is because the camera is effectively automatically determining the exposure and your scene goes outside the bounds of the cameras available programmed exposure. If so, it's another bug (as one might expect the EVF to become darker).

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In the A, S and P modes the exposure is adjusted automatically by the camera and the histogram you see on the LCD or in the viewfinder is not the histogram of the image you are about to take but that of the "correctly" exposed image of the current scene. This is the "target" histogram and the user can change this target only by dialling in some EV compensation. When you do that in the A, S and P modes, the histogram should move accordingly.

In the example above the camera cannot open aperture wider than F2.0 to achieve the target exposure when the user fixes ISO 800 and SS 1/250s. Hence F2.0 is in red. The camera still lets you take the shot. Underexposed, as expected.

If there was more light or the SS was slower and the aperture value was not in red, the recorded image would have had the same histogram as the one seen in the shooting mode.

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Dem, that is what I am discovering... I need to retool my thinking on how the camera works (and prevent the aperture ring from sliding over to "A" again.) I operated under the assumption that it should reflect that underexposure no matter what(similar to how most DSLR's light meter reflects exposure using the the camera's current settings to determine if the scene is under exposed, over exposed, or just right. I have been shooting manual with the cameras, so this issue shouldn't come up again... but at least now I know why it did what it did. Thanks

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