Dynamic Auto-focus in a Nikon D5

[Ann_JS]

It actually applies to shooting RAW in all Nikon cameras — and probably to other makes too (but I have no experience of those).

You have more than a stop of hidden-from-the-Histogram non-blown Highlights head-room on most, if not all, Nikon DSLRs!

Use it — and you will get your details and colours back in the shadows and can stop worrying about Noise!

 

[photogramps]

my meter is set for +0.6 EV internally.

Can you explain how you are doing that please?

 

[Tim Robinson]

Can you explain how you are doing that please?

Ditto - given the amount of lowlight work I do and Ann's comment above regarding "all Nikon cameras" this suddenly becomes extremely interesting to me...I don't have a D5, but if I can leverage this on my D810 and even D750 then I will.

 

[Palouse]

In a D810 (From Thom Hogan's Guide)

#B7 Meter Compensation
(Fine-tune optimal exposure)

The D810 models have a Custom Setting that allows you to individually dial in a permanent exposure compensation for each metering system. This fine tuning of the meter systems is “hidden”; in other words, it doesn’t show up in the metering displays as exposure compensation.

To use it, you first have to agree that you know the compensation won’t show up in the camera displays. And you can opt for having this adjustment apply to all or selected metering modes.

 

[Palouse]

To steal a bit more from Thom Hogan's Guide:

Recommendations:
1.Personally, I’d stay away from altering the matrix meter system. 
Because the matrix metering system already dials in secret compensations based upon the pattern of lighting and the colors of the subjects it sees plus the scene it thinks it recognizes, you really would be adding meter compensation on top of an unknown. I’ve seen situations where the matrix meter gets the exposure dead on and others where it misses by a half stop or so. So if you dial in a half stop compensation, case one is now off by a half stop and case two is “fixed.” Did you gain anything? I think not. If the matrix metering system is inaccurate for you in some situations, use one of the other metering systems instead. 


2.If you always spot meter off of a gray card, consider dialing in the appropriate compensation for the spot metering system to compensate for the slight difference in the way camera meters are calibrated. Note I said “always.” This Custom Setting would always override the metering null value, so you have to meter consistently for this to be of exceptional use. Gray cards can vary as much as a half stop from what would be middle gray (128,128,128*), and if you spot meter with multiple cameras, they can easily be different by as much as a half stop due to manufacturing tolerances. This is one way to compensate for such differences. 


3. If you don’t use a gray card to meter but find that you’re consistently dialing in a specific exposure compensation in all situations, consider using this custom setting to adjust the camera. The ISO standard for meter calibration allows up to about a half stop of error, so it is entirely possible that your 
 camera is calibrated incorrectly. If so, this is the function to use to fix that.

*Technically, this is the “middle” of the bit depth (from 0,0,0 to 255,255,255). Practically, the actual bit value of a photograph of a middle gray test chart in sRGB Color Space should be 117,117,117.

 

[Tim Robinson]

Rockin'....thanks Nick!

 

[designdog]

OK, tried a little test. These were shot with the new 28mm 1.4e, at f4 1/80. In order, no exposure compensation, iso auto got me 720; +⅓ and 1100 iso, -⅔ and 450 iso. All center weighted.

These were processed in ACR, Camera Neutral, some small tonal adjustments and curves in ACR. Only PS work was smart Sharpen. Note: the ACR adjustments were pretty much the same for all three.

To my eye, the -⅔ is the better image...

Subscribe to see EXIF info for this image (if available)

Subscribe to see EXIF info for this image (if available)

Subscribe to see EXIF info for this image (if available)

 

[designdog]

I think I am going to combine the advice here and use the custom setting to put a -⅓ ev on everything. I will start shooting these complex dynamic range scenes with average metering. This weekend I will hijack my wife and build a custom color profile (she can hold the color card, plus she has excellent skin tone!) Thanks for all the help!

PS: somewhere in the dim recesses of my mind I recall a correlation between Matrix Metering and 3D Autofocus, or something like that. Perhaps not...

 

[Palouse]

plus she has excellent skin tone

And the skill to be a Voice Activated Color Card Stand!

 

[Ann_JS]

Grey-card Spot Metering under exposes too!

And how many people are spot-meter reading from the same grey-card in every situation anyway?
It is actually far more accurate if Spot-metering to use a pure WHITE object and about +3 EV — even +3.03 EV with some cameras.

What "looks the best to me" when using 3rd party Profiles (or, even worse, some canned "Preset") has very little to do with actually getting the best possible exposure to start with; and from that point forward, using the software to its fullest capabillity so that your HLs read in the 244 range and your deep shadows read at about 008— with the extremest Black pixels just nudged to zero and a specular HL nudged to 255.

Set Sample Points when editing; pay attention to the numbers (NOT to how it looks to your eye on your monitor!) and you won't go wrong.

I don't want to be unkind, but none of those renderings of the statue in the shade are doing justice to what the camera could capture in those circumstances. And most of the stressing about "Noise" could be ameliorated if camera users stopped being concerned with how the shot appears on the back of the camera, in the Histogram or paying attention to those useless Blinkies!

The only time when you should be using Negative EV is when you are shooting a bright object against a BLACK background and wish that background to render as Black and not as 12% Grey!
Night shots, Concert and Theatrical photography would be among the few occasions for using Minus EV.

Matrix metering is unreliable because it uses AI and averages the entire scene — which is usually detrimental to the main subject. The under-exposed, muddy-toned, noisy foregrounds which I see in so many landscape photographs is the direct result of using Matrix metering coupled with Minus EV.

If you are serious about getting optimal results from your camera, just get RawDigger and see exactly what Data is being recorded in your RAW files because, I guarantee, that it is very different from what that useless Histogram is indicating!

 

[Ann_JS]

The statue photograph is very low contrast so you are not operating in anywhere near the full Dynamic Range so your metering can be off by several stops in both directions without it making much difference. High DR, as in your pond shot, is an entirely different ball-game!

But here is your "Plus" shot as you presented it.

Subscribe to see EXIF info for this image (if available)

Look at the Sample-point read-outs:
Notice that the road (which should probably be neutral grey) shows a very high Blue reading (162, 162, 183) ?
Adjust the Colour Temp and Tints sliders until the three colours read approximately the same.

Now use the other sliders so that important shadows (in which you want to see detail) are in the 008 zone or brighter; and important HLs read at about 244. Then nudge your darkest Pixel to zero and the brightest white pixel to 255 and you have a very different result.

Some gentle sharpening (Deconvolved not USM!) and zero Luminance Noise reduction produced this result:

Subscribe to see EXIF info for this image (if available)

Tip: Hold down the Option key while moving the Black and White sliders to reveal the location of the darkest and lightest pixels.

 

[Beagledog]

Grey-card Spot Metering under exposes too!

And how many people are spot-meter reading from the same grey-card in every situation anyway?
It is actually far more accurate if Spot-metering to use a pure WHITE object and about +3 EV — even +3.03 EV with some cameras.

What "looks the best to me" when using 3rd party Profiles (or, even worse, some canned "Preset") has very little to do with actually getting the best possible exposure to start with; and from that point forward, using the software to its fullest capabillity so that your HLs read in the 244 range and your deep shadows read at about 008— with the extremest Black pixels just nudged to zero and a specular HL nudged to 255.

Set Sample Points when editing; pay attention to the numbers (NOT to how it looks to your eye on your monitor!) and you won't go wrong.

I don't want to be unkind, but none of those renderings of the statue in the shade are doing justice to what the camera could capture in those circumstances. And most of the stressing about "Noise" could be ameliorated if camera users stopped being concerned with how the shot appears on the back of the camera, in the Histogram or paying attention to those useless Blinkies!

The only time when you should be using Negative EV is when you are shooting a bright object against a BLACK background and wish that background to render as Black and not as 12% Grey!
Night shots, Concert and Theatrical photography would be among the few occasions for using Minus EV.

Matrix metering is unreliable because it uses AI and averages the entire scene — which is usually detrimental to the main subject. The under-exposed, muddy-toned, noisy foregrounds which I see in so many landscape photographs is the direct result of using Matrix metering coupled with Minus EV.

If you are serious about getting optimal results from your camera, just get RawDigger and see exactly what Data is being recorded in your RAW files because, I guarantee, that it is very different from what that useless Histogram is indicating!

Ann I have to agree with you totally! Nikon's matrix metering, and all of their modes tend to leave 1 stop of headroom in the images to avoid blocked highlights. This is like throwing away 1/2 of your photo-site's well capacity away. On my cameras I have set the exposure up 2/3 of a stop, it still gives some room for whites not to be blocked but really reduces the noise in the blacks.

As for the Dynamic focus modes, I really appreciate your insights. I knew the D500 was different, but I didn't know how. your advice will help me get better shots.

Thanks,
alexis and Georgie Beagle

"Raw Digger rocks! , every photo-beagle needs it and Fast raw viewer!" - Georgie Beagle

 

[Ann_JS]

Georgie Beagle sees the light!
(As does his happy owner!)

 

[Retief]

Several times here, and in other places, Ann and I have had our differences. This thread is not one of them

"Blinkies" don't bother me a whole lot anymore, not that I want the whole dang LCD looking like a spotlight!

I wonder if this just may be one of the factors in why some of us seem to not have much trouble with ISO over 1600 on the D500?

To give Ann a whole bunch of credit here, as well as folks like Bill Claff, I really appreciate you folks who go to the trouble of figuring out the "why's" and then are kind enough to explain it to the rest of us in terms we can, mostly, understand.

 

[Palouse]

To give Ann a whole bunch of credit here, as well as folks like Bill Claff, I really appreciate you folks who go to the trouble of figuring out the "why's" and then are kind enough to explain it to the rest of us in terms we can, mostly, understand.

Nicely put.
After reading her posts about exposure here I spent much of the day with my D810 and Thom's guide trying to educate myself.
Now if the darn WA smoke would stay the heck away . . .

 

[Ann_JS]

Thank you both so much for your very kind remarks.

 

[designdog]

All right, all right , all right! I am going to cave in to the experts here and - despite an almost physical contraction on my part - start applying a +⅔ exposure compensation on my D5. And shoot in average metering mode. We will see. I promise I will give it an honest and fair trial!

Some related thoughts:

- not an absolute novice in processing, as I said before. I go back to correcting with samples a la Dan Margulis
- in some ways I may be trying to justify my recent purchase of a $6500 camera in the midst of the D850 love in
- I seem to be a better technician than a photographer, although I am improving
- I actually do really love my D5!

 

[Ann_JS]

By "average metering", do you mean "Center Weighted"?
I find it gives more consistent results than Matrix does because it is reading that smaller circle (instead of the whole frame) which probably contains your most important subject matter.
Matrix seems to put too much emphasis on the Highlights such as a small strip of sky.

 

[designdog]

Yes - "Center Weighted" metering...

 

[designdog]

So I am continuing to learn the best settings for the D5.

Ann, if you see this, please recall your earlier comment:

In the Menu Settings/Fine-tune Optimal Exposure (b7 on the D5):
I have set my in-camera meters to +0.6 EV for the Matrix meter;
and +1.0 for the Spot Meter (because of the way that I use a spot reading).

I then use the external ±EV controls to adjust exposure on the fly for special circumstances (like black cats down a coal mine).​

On my D5, I can only make this setting (b7) in increments of x/6. So would your "+0.6" be equivalent to my +4/6?

Thanks...