X100F ISO Accuracy

[SaveKodak]

This might be wayyy off base, but I remember reading that Fuji has been employing some differing standards regarding their ISO rating.

My situation is this, when I shoot chrome or am in a difficult lighting situation, I've been using a Sony A7 as a meter. Honestly this has worked far better than I would have expected. It's a little clunky, but I've been nailing my exposures far more consistently now when I use my M4, Rollei 2.8E, or Pentax 6x7. I actually first heard of doing something like this from a pretty good 4x5 landscape shooter who stopped using his spot meter and bought an old Olympus M4/3s. But, I'm selling my M4 and all my M lenses (My F6 won the 35mm battle, I have more lenses for it and it's just a fabulous camera). So instead of buying a new Sony lens, I've been thinking of swapping my A7 for an X100F. I had thought of getting the X70 (much smaller) but, no EVF. Seems like I'd get a smaller camera with a nice lens included...but...

TL/DR Will my X100T be an accurate meter for film like my Sony has been? Or is it off by 1/3rd-2/3rds like I had heard... Like I said, this question SOUNDS dumb to me, but I thought I should check...

Even if it is off, perhaps I could dial it in using exposure comp...

 

[sheins1928]

After having had my x100f for two weeks, I can't say I've come across any issues with the light meter/ISO reading. With shutter speed, aperture, and ISO all set the same, it seems to give essentially the same result as my 5d MKIII when I shoot with both of them at the same time and place.

But while we're on the subject, do any x100f users know if it's possible to MOVE the light meter in the OVF from the left-hand side, where it sits normally, to the bottom, like the x100T and conventional DSLRS? The light meter, I've found, is difficult to see in bright situations given that it's just plain white, TINY in the viewfinder, and way to the left. This is my only real gripe with the camera, period.

 

[jsrockit]

There are many threads all over the internet that state that Fuji rates its ISO differently than other manufacturers. I'm not sure which ones are myth or truth. I only use Fuji these days, so I no longer care. Perhaps a cheap light meter could be the better option if you aren't sure.

 

[willie_901]

With exposure compensation invoked, the X100F will be useful for estimating film exposure.

It will take you a bit of time to set up the X100F so it meters similarly to the A7. I suggest you use a gray card and a tripod. Also, differences in lens T-fators may be relevant.



ISO is ambiguous. There is no single definition for digital cameras.

The problem is: The International Organization for Standardization has at least three unambiguous definitions and measurement protocols for digital cameras. Their members agree to use one of these. In Japan, Camera & Imaging Products Association members agree to adhere to one of two unambiguous ISO definitions and measurement protocols.

So there are at least five explicit definitions and measurement protocols manufacturers can use to publish an authentic ISO specification.

DxO uses a completely different unambiguous definition and measurement protocol.

So which ISO definition is appropriate? Which is the most meaningful? How do you define cheating with this many accepted ISO standards?.

The data I've seen indicates FUJIFILM's metering is about 1/2 to 2/3 of a stop different than most other brands. This seems to be a poor decision because it invites avoidable criticism. Obviously FUJIFILM is not going to change.

However, it doesn't matter.

All that matters are differences in the analog signal-to-noise ratio at base ISO when the shutter is open. For dual-gain cameras (like the X100F) the SNR at the second sensor full-well capacity (ISO 800) matters too. For cameras with older analog ISO amplification technologies, knowing what ISO ranges have the lowest read noise component matters.

Light meter calibration differences between digital cameras have no effect on technical image quality (SNR). Raw file SNR differences do.

 

[SaveKodak]

Seems like, with a grey card and a test roll, I could make this work. Sounds good! I think I'll enjoy having the X100F more than a Sony anyway. If I could afford an A9, maybe I'd stick with Sony, but they don't have anything that can touch my 58/1.4G for rendering, and of course, no F6. 🙂

 

[ptpdprinter]

Perhaps I misunderstood, but since you are selling your M4 and lenses, would you only be using the Fuji X100F as a meter for the Rollei 2.8E and Pentax 6x7? Does seem a bit convoluted when a good incident or spot meter would be smaller and less expensive. Did you really use your A7 as a meter for your M4?

 

[SaveKodak]

Perhaps I misunderstood, but since you are selling your M4 and lenses, would you only be using the Fuji X100F as a meter for the Rollei 2.8E and Pentax 6x7? Does seem a bit convoluted when a good incident or spot meter would be smaller and less expensive. Did you really use your A7 as a meter for your M4?

You would think an incident or spot would be the same but in practice, pre-visualizing the highlight and shadow placement on an EVF. With negative film I don't bother, but when using chrome or B&W even, it helps a lot. And actually taking a number of readings with a Sekonic is not any more or less easy than using an A7.