I’ve recently been out shooting with the new Sony a6400 mirrorless camera. This is the latest in the smaller APS-C cropped mirrorless cameras in the Sony Alpha range (they also have full-frame cameras in the Alpha range, such as the a7r III).
It has a 24.2 MP APS-C Exmor CMOS sensor and Sony’s BIONZ X on-board image processor. What I’m focusing on here is the stills performance through the ISO range, which goes from ISO 100 to a whopping ISO 102400.
- 24.2MP APS-C Exmor CMOS Sensor
- 425 Phase- & Contrast-Detect Autofocus Points
- Up to 11 frames per second shooting
- Native ISO Range (Photos): 100 – 32000
- Extended ISO Range (Photos): 40000 – 102400
- Fastest Shutter Speed: 1/4000
Native ISO vs Extended ISO
But that’s not to say that all of that ISO range is equal. The Sony a6400 has an ISO range from 100 to 102400.
But not all of that is “true” ISO range–also known as native ISO range–that’s down to the responsiveness of the sensor itself. The native ISO range is 100 through 32000.
To get above that, you need to tap into the extended ISO range, where software takes over to boost the signal and cleans up the image.
In practice, the performance in the native ISO range is much better than in the extended range. But even within the native ISO, as you move higher, you start getting more noise/grain, less dynamic range, and less accurate color rendition. Once you get into the extended range, those flaws become much more noticeable more quickly. Which makes these very high ISOs more like break-the-glass options than for everyday shooting. But if you are going up to those very high ISOs, you’ll probably get better results when shooting JPG. That’s because the camera’s built-in processor is optimized to deal with the specific characteristics of the images produced by this camera. You might well be able to get similar results yourself using other apps, but it’s likely to involve a fair amount of processing and tweaking.
ISO Range Examples
Here are some sets of images I shot with the a6400 throughout the ISO range to illustrate the ISO performance. The first set was shot using a tripod; the second was shot hand-held.
Both were shot in Aperture priority mode, with only the ISO being adjusted between each shot and the camera recalculating the exposure each time to provide some relative consistency.
There are a few things to note about displaying the images. These were all shot in RAW + JPG. When shooting JPG, the camera automatically processes the images in-camera, and with higher ISO images, that includes noise reduction that’s geared specifically to this camera’s capabilities. So, by default, the JPGs include noise reduction.
When shooting RAW, that noise reduction is also applied by default to them embedded JPG previews but doesn’t affect the underlying RAW data. For all of these, I’ve had Lightroom regenerate the preview from the RAW data, which means that you’re not seeing the camera’s noise reduction applied. I have left Lightroom’s default sharpening on (40, 1.0, 25, 0), which has a relatively light touch.
There are a few ways to get a closer look. To see a full-size JPG generated from the RAW files, click on each image. You can also see the camera-processed JPG versions and the unadulterated RAW versions by clicking on the links to the originals of those in the caption under each image. Each RAW file is about 25MB and each JPG about 4 to 11 megabytes in filesize, give or take.
ISO Example Photos Set #1































ISO Example Photos Set #2
This set starts higher up in the range. These were shot hand-held, which is why there’s some slight misalignment between them.
















Price & Availability of the Sony a6400
Check the current price and availability of the Sony a6400 at:
It’s available in a few different configurations, ranging from body-only to bundled with either a 16-50mm zoom lens or an 18-135mm zoom lens. You can also find good deals that include a bunch of accessories (eg., memory cards and camera bags, for starters) that are bundled together by retailers.
- 24.2MP APS-C Exmor CMOS Sensor
- 425 Phase- & Contrast-Detect Autofocus Points
- Up to 11 frames per second shooting
- Native ISO Range (Photos): 100 – 32000
- Extended ISO Range (Photos): 40000 – 102400
- Fastest Shutter Speed: 1/4000
Related
Fixing Image Quality Problems in Editing
And the general rule of thumb in photography is that it’s better to get the shot right at the time of capture rather than trying to fix it after. That’s a great aspiration, but it’s not always possible to do if you’re shooting in especially challenging conditions or bumping up against limitations or flaws in gear, conditions, or technique.
But it’s worth mentioning that there are some excellent tools available to help address common image quality issues with digital images. And they’re getting better and better all the time as the power of AI ramps up. They can deal remarkably well with anything from sensor issues like high-ISO image noise to lens issues like distortion, softness, vignetting, and chromatic aberration. (Note: I’m focusing here on corrections related to image quality, not image enhancement tools–that’s a different kettle of fish.)
All-round image processing apps like Lightroom Classic and Capture One have solid tools built in that are very good places to start. But it’s also possible to take it much further with more specialized tools. If you shoot in challenging conditions regularly and find room for improvement in the image quality coming out of the camera, these might well be worth a look (and they have free trials). Some are stand-alone apps; some integrate into image editing suites such as Lightroom Classic.
UPDATE: In April 2023, Adobe released an update to Lightroom Classic that added new AI-powered noise reduction for RAW files. It’s a powerful tool that rivals some of the dedicated apps below. If you’re already using Lightroom Classic for your image editing and organization, it’s well worth trying out.
Fixing Image Noise & High ISO Artifacts
- DxO PureRAW 3 (only works on RAW files, but since was updated to version 3, it has become my go-to app for this kind of thing)
- DxO DeepPrime
- Topaz Labs’ DeNoise AI
Fixing Lens-Related Optical Issues
- DxO PureRAW (again offers an impressive suite of automatic fixes that are applied before you start editing the images)
- DxO ViewPoint (correcting for lens distortion and geometry skews)
- Topaz Labs Sharpen AI (in addition to standard unsharp tools, includes focus correction and shake reduction)
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Images and product information from Amazon PA-API were last updated on 2023-05-31 at 16:09. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon Site at the time of purchase will apply to the purchase of this product.