D850 vs. Df - in real life

[rodeo_joe1]

That's a bit harsh on kitties!

Not as harsh as the local moggies have been on the birdlife in my garden!

 

Chain the little savages up, I say.

The only time I actually used the viewfinder shutter was when I changed the eyepiece on my D700.

You don't use a tripod then?

All Nikons leak light through the viewfinder onto their metering system. So if you don't have your eye to the finder in reflex-viewing mode, then you're likely to get underexposed results.

[raczoliver]

You don't use a tripod then?

All Nikons leak light through the viewfinder onto their metering system. So if you don't have your eye to the finder in reflex-viewing mode, then you're likely to get underexposed results.

 

I'm not sure I understand. In reflex-viewing mode I actually have to be looking through the viewfinder to see what I'm photographing, don't I? Most of the times I use live view when on a tripod, and even if not, most likely I have the exposure mode and ISO set to manual, in which case exposure is not going to change after I move away from the camera and light enters through the viewfinder.

 

Or are you saying it leaks light around the mirror while the exposure is being taken?

[Nick D.]

I'm not sure I understand. In reflex-viewing mode I actually have to be looking through the viewfinder to see what I'm photographing, don't I? Most of the times I use live view when on a tripod, and even if not, most likely I have the exposure mode and ISO set to manual, in which case exposure is not going to change after I move away from the camera and light enters through the viewfinder.

 

Or are you saying it leaks light around the mirror while the exposure is being taken?

When you take picture in Live View , mirror is activated for the moment for exposure meter to take reading. Manual is right, so is Sandy. :)

[Nick D.]

To OP, can't compare images with different lighting, different ISO number, different shutter speed and different composition. If you want run the test: tripod, same lighting, static subject .

[raczoliver]

When you take picture in Live View , mirror is activated for the moment for exposure meter to take reading. Manual is right, so is Sandy. :)

 

I remember the D700 doing that in "hand-held live view" mode. The D850 doesn't. Perhaps the Df does, that's why the manual tells you to cover the eye piece. Neither the D850's, nor the D810's manual does.

[raczoliver]

Edit: Ok, I just recalled that there is a function on the D850 called "silent live view photography", which I turned on right after I bought the camera and never turned it off after that. That might be what makes the difference, the mirror definitely doesn't move before taking a shot in live view, it is completely silent.

[mike_halliwell]

Many of the early DSLRs with Live View did a raucous set of thuds and clanks before and after pressing the shutter.

 

.. and i recall the complete uncertainty as to what the aperture was for viewing the LV feed as opposed to that set for the actual exposure. I often wondered if this lead to bad focus due to focus-shift on stopping down.

[BeBu Lamar]

When you take picture in Live View , mirror is activated for the moment for exposure meter to take reading. Manual is right, so is Sandy. :)

 

Not on the Df I can assure you that. When you switch to live view the mirror goes up and stay up until you turn off live view. The meter reading continues to work while the mirror is up.

[BeBu Lamar]

You know more than the Manual?

 

Yes even more than Nikon tech. When I did the troubleshooting of my Df with Nikon tech on the phone they said it's impossible to have bad meter reading in viewfinder mode and have perfect reading in live view. And yes I demonstrated that to them that the 2 metering systems are completely independent.

[Sandy Vongries]

Yes even more than Nikon tech. When I did the troubleshooting of my Df with Nikon tech on the phone they said it's impossible to have bad meter reading in viewfinder mode and have perfect reading in live view. And yes I demonstrated that to them that the 2 metering systems are completely independent.

Whatever you can convince yourself and others of must be at the least "truthy".:rolleyes:

[mike_halliwell]

I assume (!) that in LV, the metering considers the light reaching the sensor at that aperture, whatever it is.... and calculates what's needed for the exposure actually set.

 

Once LV is activated and the mirror lifts, I guess an indeterminate amount of light could reach the 'normal' exposure module.

 

... and with the mirror down (and shutter closed) no light can reach the sensor.

[BeBu Lamar]

Whatever you can convince yourself and others of must be at the least "truthy".:rolleyes:

 

Sandy,

This is not nice because what I said is the truth. Please do not accusing me of lying. You call me stupid is fine as I don't know everything but a liar I am not. Please do not call me a liar.

[Sandy Vongries]

Read what you like into my words. I could have read your post #13 the same way.

[rodeo_joe1]

I'm not sure I understand. In reflex-viewing mode I actually have to be looking through the viewfinder to see what I'm photographing, don't I?

Only if you want a bad back when the tripod's set lower than eye-level. And no, if you can see the subject directly and the framing is fixed, then there's absolutely no need to be looking through the camera.

 

With a formal portrait, for example, it's easier to communicate with the sitter and get a good expression if you're face-to-face with them, and not mumbling from behind a camera. Other subjects often require anticipation, which is easier if you have the panoramic view and peripheral vision that looking directly at the subject gives; rather than the tunnel-vision of staring through the camera.

 

Whatever. If you haven't got your eye to the finder with the blind open, then there's a good chance of the metering being wrong.

 

Having said that. I've never bothered using the eyepiece blind with LiveView. Because if the programmers of a camera are stupid enough not to lock the exposure from the sensor at the right moment, then they really don't deserve to be selling cameras.

[BeBu Lamar]

I just verified again that stray light entering the viewfinder eye piece has no effect on the meter in live view with the Df. I set the Df in A mode, f/8 and the lens cap on. Both modes show f/8, 25 sec which means the meter detects no light. In viewfinder mode when I put a flash light against the eyepiece and turn it on the shutter speed changes to 1/80 which means the metering sensor in the viewfinder sees a lot of light. In live view mode the shutter speed stays at 25 sec.

[raczoliver]

Only if you want a bad back when the tripod's set lower than eye-level. And no, if you can see the subject directly and the framing is fixed, then there's absolutely no need to be looking through the camera.

 

With a formal portrait, for example, it's easier to communicate with the sitter and get a good expression if you're face-to-face with them, and not mumbling from behind a camera. Other subjects often require anticipation, which is easier if you have the panoramic view and peripheral vision that looking directly at the subject gives; rather than the tunnel-vision of staring through the camera.

 

Whatever. If you haven't got your eye to the finder with the blind open, then there's a good chance of the metering being wrong.

 

Having said that. I've never bothered using the eyepiece blind with LiveView. Because if the programmers of a camera are stupid enough not to lock the exposure from the sensor at the right moment, then they really don't deserve to be selling cameras.

 

I guess you're making valid points there. In practice, my formal portraits are all taken with studio strobes, which means manual exposure mode. The other scenario that I sometimes find myself in is landscape photography, when I have the composition set up and would stand there for an hour or so, taking several pictures in the changing light. Again, I would probably be using live view to set up the shot, acquire focus etc., leave the camera in manual exposure mode, check exposure every few shots by reviewing the histogram and adjust as necessary. In short, light entering the viewfinder has never been an issue for me in practice.

[mike_halliwell]

The only time I've really messed up an exposure i was trying to shoot a butterfly and i couldn't get close enough, so i slowly pushed the camera forward whilst looking through the VF keeping centre AF point on target.

I got to full stretch, about 50cm and took the shot. It came out about 2 stops under. The sun was behind me going straight into the VF.

I couldn't see the backscreen due to the sun over my shoulder reflecting badly...so LV wouldn't have worked.

I have a Hoodman clone that may have helped, but even then having the sun behind me and the screen at arms length may not have worked.

I managed to dial in +2 with my right hand and all was OK. Not a great shot though!

[tonybeach_1961]

The reason a viewfinder cover or shutter is provided is so that light coming in the viewfinder will not impact exposure with live view.

That's one reason to use it.

I think the purpose is to prevent stray light from throwing off the meter reading when using auto-exposure and the photographer's head is not blocking the viewfinder, such as when using the self-timer.

That's another reason to use it. However, in both instances I rarely see a difference in metering.

In fact when you use live view you can shine a flash light into the viewfinder and it doesn't affect the meter reading. In live view nothing in the viewfinder is used. Not the metering sensor or anything. The mirror is up and no light in the viewfinder can reach the sensor. The imaging sensor is now used for imaging the picture of course, provide a view on the live view, to measure light intensity for meter and to perform AF. It's 2 totally independent system except using the same sensor to acquire the image.

You've done this test? I just did it on my D500 and D800 (both with the front lens cap on) and I could see the glare from the flashlight appear in Live View. I also did three five second exposures with my D800 with the front lens cap on and a flashlight shining into the viewfinder, and the one with the shutter curtain engaged showed no glare, the one without it engaged showed the same glare I saw using Live View, and another one without the viewfinder curtain engaged using Live View also showed the same glare. I did this test years ago on my D300 and Sony A850 and the Sony did much worse; I just now did the test again on another D300 (A850 was sold and not replaced) and it only showed very little glare after a five second exposure with my flashlight shining into the viewfinder. I've known for years now that if the sun is shining on the back of the camera or I'm shooting long exposures in the dark that I definitely want to keep the viewfinder covered (I used to put my finger over the D300 viewfinder).

[mike_halliwell]

So, on modern DSLRs, there's a light path from the VF around the raised mirror to reach the sensor? Really poor design....:(

Or is it through the part of the mirror that is only partially silvered so the AF module behind the mirror can see before it's raised?

Edited March 1, 2021 by mike_halliwell

[rodeo_joe1]

Or is it through the part of the mirror that is only partially silvered so the AF module behind the mirror can see before it's raised?

That shouldn't be the case. There's a small hinged secondary mirror behind the semi-silvered part of the main mirror. This flips up to cover the semi-silvered part.

 

Entirely anecdotal and FWIW. I remember one photographer, having just bought an Olympus OM-1, singing its praises to anyone that'd listen. Then a few months later, having discovered that it leaked light past the (supposedly) raised mirror, cursing Olympus roundly.

[ilkka_nissila]

I haven't noticed a situation where stray light through the ocular affected exposures in recent years. But I guess the manufacturer's intention with the ocular shutter is that in case it does happen, you can use the shutter to block it.

[BeBu Lamar]

That's one reason to use it.

 

That's another reason to use it. However, in both instances I rarely see a difference in metering.

 

You've done this test? I just did it on my D500 and D800 (both with the front lens cap on) and I could see the glare from the flashlight appear in Live View. I also did three five second exposures with my D800 with the front lens cap on and a flashlight shining into the viewfinder, and the one with the shutter curtain engaged showed no glare, the one without it engaged showed the same glare I saw using Live View, and another one without the viewfinder curtain engaged using Live View also showed the same glare. I did this test years ago on my D300 and Sony A850 and the Sony did much worse; I just now did the test again on another D300 (A850 was sold and not replaced) and it only showed very little glare after a five second exposure with my flashlight shining into the viewfinder. I've known for years now that if the sun is shining on the back of the camera or I'm shooting long exposures in the dark that I definitely want to keep the viewfinder covered (I used to put my finger over the D300 viewfinder).

 

I have done the test. There is no influence on exposure with live view. There is significant influence on exposure when in view finder mode. When in viewfinder mode the shutter speed changes from 25 sec to 1/80 sec.

[raczoliver]

I have done the test. There is no influence on exposure with live view. There is significant influence on exposure when in view finder mode. When in viewfinder mode the shutter speed changes from 25 sec to 1/80 sec.

 

I just tried it too with my D850, but my results weren't as good as yours. ISO 64, f/5.6, aperture priority, lens cap on, shine flashlight in viewfinder. In viewfinder mode the shutter speed goes from 30'' and more than three stops underexposed to 1/1600. In live view it goes to 2'',and there is also an obvious glow visible on the LCD.

 

So why do some camera manuals tell you to cover the viewfinder for live view photography, while others (the majority, it seems) don't?

[tonybeach_1961]

I just tried it too with my D850, but my results weren't as good as yours. ISO 64, f/5.6, aperture priority, lens cap on, shine flashlight in viewfinder. In viewfinder mode the shutter speed goes from 30'' and more than three stops underexposed to 1/1600. In live view it goes to 2'',and there is also an obvious glow visible on the LCD.

 

So why do some camera manuals tell you to cover the viewfinder for live view photography, while others (the majority, it seems) don't?

In real world usage it's a very marginal issue. I stress test to see what I normally won't see so that I can avoid having unforeseen issues arise in the real world.

 

Marketing probably plays a role too. If you admit there might be an issue under extreme conditions and your competitor doesn't, some will take that to mean you have a problem and your competitor doesn't.

[tonybeach_1961]

I have done the test. There is no influence on exposure with live view. There is significant influence on exposure when in view finder mode. When in viewfinder mode the shutter speed changes from 25 sec to 1/80 sec.

You tested metering, but not your claim that "The mirror is up and no light in the viewfinder can reach the sensor."

 

FWIW, I see some but not much change in metering using Live View on my D800 and D500 when I point a flashlight into the viewfinder (as opposed to just using the viewfinder where I see a lot of change in metering), and I can actually see glare in Live View on both cameras when doing that (much more on my D800 than on my D500). Perhaps your Df is different than all four cameras I've used, but I doubt it.