Fujifilm X100VI ISO Test: Real-World Sample Images (ISO 64 – 51,200)

The Fujifilm X100VI’s base ISO is 125, and its native ISO range is 125 to 12800. Extended settings add ISO 64, 80, and 100 below that and 25600 and 51200 above, for a full range of 64 to 51200.¹

The samples below show how each setting looks in real photos, with the original files to download.

The original RAW files for the images in this post are available to subscribers to my newsletter on the RAW file downloads page. The page is password-protected; the password is in the newsletter’s welcome email. The JPG versions linked in the captions stay free.

It’s common now for cameras to have very wide ISO ranges. But what does that mean in practical, visual terms?

The reality is that not all of that ISO range is going to result in output where every photographer is going to be happy with the image quality.

And different photographers will have their own personal threshold for where the image quality starts getting too degraded (and that might shift depending on the type of shot).

So that’s why I’m sharing these images here: so that you can see some real-world photos with the Fujifilm X100VI in order to have some practical and visual understanding of how this camera performs in low light.

You can see the examples below. I’ve used several different scenes and included multiple images at different ISO within each scene.

The Fujifilm X100VI’s ISO range

Native ISO Range: ISO 125 – 12,800
Extended ISO Range: ISO 64, 80, 100 (Low) / ISO 25,600, 51,200 (High)
Test Format: Uncompressed RAW + Fine JPEG
Base ISO (Video): ISO 125 (Standard) / ISO 640 (F-Log) / ISO 1250 (F-Log2)
Physical Dial Limit: ISO 12,800 (Use “C” setting for higher/lower)

Range	ISO values	How you get there
Native	125–12800, in 1/3-stop steps	The sensitivity dial, or Auto ISO
Extended low	64, 80, 100	Dial set to C, then the front command dial
Extended high	25600, 51200	Dial set to C, then the front command dial

Base ISO is 125. That’s the setting that gives the most dynamic range and the least noise.

The extended settings aren’t on the dial itself. Set the dial to C and turn the front command dial, and the range runs from 64 to 51200. Fujifilm warns that the extended values “may reduce dynamic range or increase mottling.”

Two limits catch people out:

• The extended settings need the mechanical shutter. With the electronic shutter, the camera limits you to ISO 125–12800.
• Auto ISO stays inside the native range. Its maximum can be set from 400 to 12800, so it never uses 25600 or 51200.

Particularly as you get higher up the ISO range, the image quality degrades. You start to get grainier images, narrower dynamic range between shadows and highlights, and degraded color fidelity. Those issues become exaggerated in the upper extended ISO range.

Watch the step from ISO 400 to 500

Rico Pfirstinger, author of The Fujifilm X100VI, found that the sensor has a second base ISO. Called dual conversion gain, it switches on automatically at ISO 500 with DYNAMIC RANGE at DR100%. Read noise drops when it does, so ISO 500 costs less than the jump in numbers suggests. There’s no menu setting for it, and Fujifilm doesn’t mention it in the manual.

With DR200% the switch happens at ISO 1000, and with DR400% at ISO 2000.

The low extended ISOs cost you highlights

ISO 64 isn’t a genuinely lower sensitivity. Pfirstinger explains that the camera records an ISO 125 frame one stop brighter, then darkens it again in processing. The result has one stop less highlight range than ISO 125, so bright skies and clouds blow out sooner.

ISO 80 and ISO 100 work the same way, but start from ISO 160 and ISO 200. Pfirstinger strongly advises against them.

The catch with all three: the live view and live histogram don’t show the lost highlight room, so nothing warns you before the highlights go. If you use ISO 64, use it deliberately, in manual exposure mode, for extra contrast on a dull day. Don’t leave it set in P, A, or S.

The in-camera noise reduction

MENU > IMAGE QUALITY SETTING > HIGH ISO NR

HIGH ISO NR sets how hard the camera smooths noise in its JPEG and HEIF files, from −4 to +4. Higher values remove more noise and smooth fine detail with it. Lower values keep more texture and more grain.

It’s a JPEG setting. It doesn’t change the RAW data, which is why the RAW files below look noisier than the JPEGs once you open them properly. Pfirstinger notes that most Fujifilm “film recipes” set it to −4 and add grain instead.

The samples on this page use the default.

MENU > IMAGE QUALITY SETTING > LONG EXPOSURE NR

LONG EXPOSURE NR is a separate setting for long exposures. With it ON, the camera takes a second, dark frame and subtracts it, which removes hot pixels. Pfirstinger notes that this doubles the wait. It has no effect with the electronic shutter.

For cleaning up RAW files afterward, see Lightroom Denoise and my DxO PureRAW test on the X100V.

What the lab tests found

It helps to know what independent testers measured before you look at the samples.

ePHOTOzine’s lab tests found X100VI images clean through ISO 400 and still good through ISO 3200. Noise creeps in with a sudden drop in quality at ISO 6400, gets more obvious at 12800, and swamps the image at 25600 and 51200.

Pfirstinger rates ISO 25600 as still quite usable for black-and-white JPEGs with the ACROS film simulation, and 51200 as an emergency setting.

A practical reading of those results:

ISO	What to expect
125–400	Clean
500–3200	Holds up well; everyday low-light range
6400	Noise visible in shadows and flat areas; fine with light noise reduction
12800	Clearly degraded; for when getting the shot matters most
25600–51200	Emergency only, or black and white

Your own threshold may be higher or lower. That’s what the samples are for.

About these sample images

There are some things worth knowing when you look at these images.

All of these are directly out of the camera without any post-processing at all. No contrast adjustments, exposure, or noise reduction.

That doesn’t mean they’re unprocessed. The camera applies noise reduction to its JPEGs at high ISO, and I left it at the default for these. It doesn’t touch the RAW data. But each RAF carries a small JPEG preview made with those settings, and that’s what many apps show you first.

The versions embedded here on this page are derived from the JPGs. They have the in-camera noise reduction applied at the default settings.

Using the links in the caption of each image, you can directly download the original RAW (RAF) and JPG files. The RAW files use the uncompressed setting and are roughly 85MB each. The JPGs are using the Fine setting and are roughly 17-25MB each.

If 85MB a frame is more than you want to deal with, the RAW compression setting is where to look. Fujifilm’s own file-count figures work out to around 47MB for a lossless-compressed RAF — roughly half the size of an uncompressed one, with no image data thrown away. I’ve used uncompressed here so the files are as raw as they can be, but for everyday shooting lossless compressed is the easier choice.

Because the in-camera noise processing applies to the JPG thumbnails embedded with the RAW files, you’ll see those first when you open the file. To see the underlying RAW file, without the processing, you’ll need to regenerate the thumbnails in something like Lightroom or Capture One.

I’ve included several sets with different types of colors, tones, and detail.

You can click on each image for a full-size version for a closer look. But, again, those versions are derived from the JPGs with the in-camera processing. For the original out-of-camera versions, use the download links in each caption.

Set 1

Set 2

Set 3

Frequently asked questions

What is the base ISO of the Fujifilm X100VI?

ISO 125. That’s the setting with the most dynamic range and the least noise.

What is the X100VI’s native ISO range?

ISO 125 to 12800. Extended settings add 64, 80, and 100 below and 25600 and 51200 above, with the sensitivity dial set to C.

Why can’t I select ISO 64 or 51200?

The extended settings aren’t available with the electronic shutter. Switch SHOOTING SETTING > SHUTTER TYPE to the mechanical shutter.

Is ISO 64 cleaner than ISO 125 on the X100VI?

No. It’s an ISO 125 exposure darkened in processing, with one stop less highlight range. Use ISO 125 unless you want the extra contrast.

More on the Fujifilm X100VI

• Best SD cards for the X100VI
• X100VI thumb grip

Explore the Fujifilm X100VI

Here’s a tool I created to help identify which buttons and dials are where — and what they’re called, because every brand has their own dialect and jargon.

Notes & References:

1. When shooting video, the standard ISO range is ISO 125–12,800. Note that using F-Log or F-Log2 raises the base ISO significantly to 640 or 1250. [↩︎]