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.
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.
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.
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.
Related
Fixing image quality problems in post
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 later.
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 machine learning 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.
Some of these work only with RAW files, and those are the ones I’ve had the best results with. But there are also good options if you’re working with JPG or TIFF files.
Fixing image noise & high ISO artifacts
The newest generation of tools can do some pretty remarkable improvements to image noise. These are some of the best tools for reducing image noise in photos. Most of them include a free trial to test out the results for yourself.
- Lightroom Classic’s Denoise tool. This was quietly added to recent versions of Lightroom Classic, and you can find it in the Develop module’s Detail panel. It only works on RAW files. It doesn’t have some of the more advanced features and more granular controls of some of the other apps here, but if you’re already using Lightroom, it’s a great option to have available.
- DxO PureRAW 5. Like Lightroom Classic’s Denoise tool, it only works on RAW files. It has become my go-to app for this kind of thing. I’m consistently amazed at how it can rescue photos with otherwise dodgy image quality from noise. It can also help with lens distortion, lens vignetting, and lens softness.
- DxO Nik Dfine. This product originated with the Nik Collection, and it focuses on the more traditional approach to digital image noise reduction. Something that’s especially notable about Dfine is that you can use U-point selections for precise application of different settings to different parts of the image.
- ON1 NoNoise AI. Its “deblurring” features are particularly notable, with an emphasis on restoring sharpness that is often a casualty in denoising operations. It works on JPG and TIFF files, and you can create sophisticated masks to apply corrections to specific parts of an image.
- Topaz Labs Photo AI. Topaz Labs used to offer its NoNoise AI as a standalone product, but it has now been integrated alongside several other image improvement tools in its Photo AI app.
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. Lightroom Classic and Capture One also have excellent built-in tools for this.
- Topaz Labs Photo AI. Topaz Labs used to offer its sharpening tools as a standalone product, but it has now been integrated alongside several other image improvement tools in its Photo AI app.
Very Helpful, thanks. I was trying to decide where to set my Max ISO