ISO test on Nikon D700

[acgiannopo]

I saw yesterday one of Tony's Northup videos on his youtube channel about ISO and it's fakeness. Less than 24 hours later, another video came up by F-stoppers making some tests in order to confirm or not Tony's claims https://youtu.be/QVuI89YWAsw.
I thought it wouldbe a good idea to perform a similar test with my older Nikon D700 which apparently doesn't have neither the iso capabilities nor the dynamic range of D850.
I took the same shot with the Nikkor 85mm f/1.4 ai-s at f/2, at iso 3200, 200 and lo 1 which stands for iso 100. I then raised the exposure in LR by the iso difference in stops in order to get same exposures. The pictures below are screenshots of side by side comparison in LR between iso 3200 and iso 100. It is obvious that noise is greater in the shots that were underexposed in camera and developed in LR later.
I guess that a modern DSLR with greater dynamic range would handle thitest better. The other thing i am thinking of is that it is propably better to take the correct exposure right in camera than trying to correct it afterwards in software. What do you think?

DSC_4274 by Achilleas Giannopoulos, on Flickr

DSC_4275 by Achilleas Giannopoulos, on Flickr

[Birna Rørslett]

The general principle of getting as much done in camera as possible still is valid. That includes an exposure to exploit all  dynamic range the camera can provide. 

[acgiannopo]

I totally agree. I guess though that printing both shots would look pretty much the same. I thing i have to make more tests in the field and see what happens.

[acgiannopo]

Another thing i noticed in post processing was that iso lo1 (aka iso 100) and iso 200 were completely the same in terms of exposure.

[Birna Rørslett]

The non-calibrated setting are not necessarily true ISO equivalent. Thus Lo1 (nominal 'ISO' 100) can be anything from 50 to 200 depending on the image contrast and light regime.

There are a lot of assumed conditions in the ISO calibration and 'proper' exposure.

For my Df, and now with the Z cameras, I know exposure should preferably be within +-1 stop of what the meter indicates, but there is sufficient dynamic range to pull out whatever needed even when exposure is off the target.

[Erik Lund]

When I get a new camera I test this for myself, for that camera, so that I know what to expect when I open the raw file in the raw converter and later in Photoshop and do post processing.


It's quite important to know if it's ok with blown highlights in a certain scene or if it's ok the blacks are blocked, this is a choice you must make when capturing the image.


This and how the grain/noise looks like at different ISO values for that particular camera and post processing.


You can get quite close to replicating the in camera processing by doing cleaver post processing for; noise reduction, clarity and contrast settings I also seen that white balance can have a huge impact on especially fringing.


Almost all of my Nikon cameras have dialed in - 2/3 of a stop fine tuned exposure metering

[Bent Hjarbo]

I have changed from D700 to D500 a couple of years ago.
I have now the problem that if there are a lot of white (snow) in the picture I need to have +1 in compensation in order to get a proper exposure, Nikon have changed something in the light meter algorithm, is there others that have the same problem? I understand that Erik don’t have it.

[Erik Lund]

The first point that one should consider is that when in Matrix metering the area where the focus point is has a huge impact on the exposure, it's simply weighted much higher than one would imagine, so when shooting a scene it's very important to have this in mind when evaluating the exposure.

Very tricky when using manual focus lenses! So pay attention

Snow scenes are always tricky - The D850 does very well but sometimes fail of course.


The metering sensors now has higher resolution and colour, so should be better, but remember that ; New is not necessarily better

[Øivind Tøien]

I have changed from D700 to D500 a couple of years ago.
I have now the problem that if there are a lot of white (snow) in the picture I need to have +1 in compensation in order to get a proper exposure, Nikon have changed something in the light meter algorithm, is there others that have the same problem? I understand that Erik don’t have it.

Yes I have noticed this; since my D500 is so new, I have yet to determine if this happens on similar subjects with my D7100, but I have not take particular notice before. Perhaps I have become more picky on the performance of D500?

[Anthony]

I think it depends on the sensor technology.  Some sensors are ISO invariant, or almost so.   With current Fuji sensors there is a boost at ISO 800, otherwise it makes little difference whether you increase the ISO or adjust on the computer.  This is very useful in situations with a wide dynamic range (eg the inside of a church) as it possible to expose for the highlights (eg stained glass windows) and boost the shadows in pp without noticeable loss of quality compared with increasing the ISO to get the shadows right.

[Peter Connan]

What do you think?

I think it depends on the camera, with some of the newer cameras caring little whether you expose correctly in camera or adjust afterwards.

Here is a shot I took recently. Both were taken from the same setup and within minutes (seconds even) of each other, with the only difference being the ISO setting, one being at ISO400, the other at ISO4000.

They were also processed identically, with the only difference being that the ISO400 shot's exposure was lifted by 3 1/3rd stops, so that the total exposure is the same. Post processing was done in Lightroom, and the camera is a D500.

Personally, I can see no difference in the stars/background, and possibly a little more detail in the foreground of the ISO400 shot...

I had the same experience with my previous camera, the D750.
To my mind, if you need a set shutter speed and aperture, and you are shooting one of the late-model Nikkors, you may as well shoot at base ISO. The only problem with doing so is that it may become impossible to see sharpness on the LCD.