A few months back I finally upgraded from my trusty Sony Nex-6 to the newer Sony a6400. I’ve only just got around to having the time to write a review. This ‘review’ will very much be a ramble about my feelings using the camera, not a technical, specialist review. If you want one of those, I highly recommend DPReview’s a6400 review.
Obviously, given the huge amount of photogrammetry I do both for myself (this website) and for work (digitizing specimens) a decent camera is important to me. I’m passingly interested in photography as a hobby, but I wouldn’t call myself a photographer (though I did once had a dozen prints for sale, and in the window of Pocklington Picture Framing, many years ago). The camera is for work, and photogrammetry, first and foremost.
The a6400 is a decent upgrade from the Nex-6, but it shares a lot of similarities particularly around form-factor, so I’ll start by saying why I went for the Nex-6 back in 2014:
I wanted a good quality DSLR, with interchangable lenses. My camera prior to the nex-6 was a Canon Powershot G10, which was great but limited by it’s small sensor size. I’d got that camera, because the Olympus E-500 that preceded it was great, but never got taken out anywhere because it and it’s lenses were so large. The Nex-6 offered a decent sized sensor, good feature set, and a good range of lenses, but the camera itself plus the 18-50mm power zoom could still fit in my coat pocket [just].
I’ve really enjoyed using the nex-6, and felt it was time for an upgrade, so the a6400 is a natural upgrade. Actually, I’ve been in desperate need for a new camera for the lab, but have failed so far to get funding, so I’ve bought the a6400 and have temporarily donated my nex-6 to the lab for undergrad and post-grad usage.
Handling/form-factor
In terms of form-factor, the a6400 is very similar to the nex-6, albeit a little chunkier. I really like the form-factor – as noted above, it’s really nice and compact, and with a small lens can just about go in a coat pocket. Meanwhile, it’s large enough for plenty of physical controls on the back.
However, it can seem a bit on the small side when you’ve a longer lens on. Here’s my 55-210mm with a 1.7x conversion lens:
And even though I’m mostly a fan of the form-factor, even I have to admit that some of the controls are difficult to reach, or not quite ideal ergonomically. Some have complained about the placement of the video record button, but I don’t mind it too much – it’s not super easy to press while looking through the view finder, but I don’t record much video anyway, so don’t notice too much.
Specs
I don’t need to bore you with numbers here – they’re easy to find with a quick google if you’re interested, as I say, check out a specialist review like DPReview if you wan that info. The headline numbers would be that it’s a 24mp, APS-C (23.5 x 15.6 mm) CMOS sensor.
The JPGS have a nice colour balance, as far as I’m concerned. They weigh in at ~17mb per image.
RAW files are uncompressed, and have plenty of information to play with. They come out at ~24mb in size.
I’ve previously discussed that I tend to shoot in JPG when I’m doing photogrammetry. This has seen a particularly vocal dissenter on twitter/social media, but I generally spend the time with the camera/lighting when taking shots that I end up with an image that is what I’d go for editing the RAW files. That being said, if I’m out and about and conditions are a bit naff, I will switch to jpg+raw, just in case.
Video-wise, it can record 4k video at 30fps, and if you drop the res to 1080p, it can record at 120fps. I haven’t run into issues with recording time and overheating, but again, I don’t record that much video.
Interesting features
I certainly won’t exhaustively list the features of the camera, because I don’t use many of them, so instead I’ll highlight some of the little things I like that are improved over the nex-6:
Touch-screen focus. This is great, you can just touch the screen to tell it where to auto-focus. Also, because the view finder is all the way on the left, you can scroll your right thumb over the touchscreen and move the focus area directly. Probably sucks if you’re left handed though.
WiFi file transfer. I was really excited about this – I’ve had wireless stuff as part of my automated photogrammetry set-up, and I thought this would be great. Unfortunately, it’s sloooooooooooooooooooooooow even on a great connection, files take minutes per image to transfer. It can be useful if I come in from a walk out somewhere, and I can just set the phone to start sending photos to my computer and forget about it, though if I’ve been taking many shots, it’ll probably run the battery down before it transfers them all. And god help you if you try to transfer 4k videos this way. Worth mentioning here that the USB connection on the camera is just 2.0, so it’s not particularly fast transferring that way either. You really need a dedicated SD card reader. Not great.
Bluetooth connection to phone. This one does come in useful. The camera can be controlled through the Imagine Edge client on an android, and I assume iPhone, phone. I don’t use that very much, but what I do use is the feature whereby the camera will passively connect to my phone via bluetooth, then use it for GPS tagging images. It usually works, but sometimes takes a little while to connect, so if I’m turning the camera on, taking a shot, and turning it off again, it doesn’t always work.
Flexible LCD screen. It tilts both up and down, and can pull out a little, but it can’t swivel out to the side. Having a flexible LCD is a major boon when you’re trying to get angles of a fossil that’s awkwardly in a display or on a shelf and can’t easily be moved.
The interface. It’s better than the nex-6’s, but that’s not saying much. Generally it’s fine, and the inclusion of a user-menu means I can put all the things I need to access regularly into that, and don’t need to go hunting in the menus too much. Sony do seem to have gotten rid of the dumb ‘apps’ they had before. Having to pay £8 to enable time-lapse on the nex-6 felt like a bit of a dick move from Sony; if the camera is already capable, charging for additional features just seems wrong.
Summary
It’s a nice camera. I like it a lot, but because it’s so like the nex-6 it doesn’t feel particularly new and exciting. Nearly all the features that matter (resolution, focusing speed and accuracy), are things that are just there in the background. The lack of excitement about it means I find using it practical, but not necessarily fun. I’m not sure what that means, or if such a comment even really belongs here.
One thing I am conscious of is how good smartphone cameras are getting. Not because they can replace a DSLR – they’re still a way off that, but because they can take great photos for photography and for photogrammetry. To me, maybe that means I don’t need to worry about having a portable DSLR any more. Maybe instead of sticking with a compact model like the a6400, I could splurge on a full-frame camera, for professional use, and just use a phone for day-to-day or spur-of-the-moment usage. I’m not sure, it’s the same problem I’m having with computers – get one device to do everything, that’s full of compromises, or nice, specialist devices for different things, but then having to lug a bunch of stuff around when you don’t know what you’ll need?
If you want a nice compact camera, with a good range of lenses, you can’t go far wrong with the Sony a6400.
If you’re interested, the a6400 can be had at this affiliate link for ~£1000 with the 18-50mm PowerZoom.
Dr Peter L. Falkingham 
Hi Peter, have you ever considered one of the Olympus (now OMDS) cameras with built-in focus stacking? This feature is really useful when you need a large depth of field. It has worked really well when making 3D models of very small objects. I use an OM-D EM-1 Mark ii, which can stack up to 15 images, providing a huge depth of field when compared to s single frame. Kind regards, Gerard
I’d love to give the Olympus camera and it’s built in focus-stacking a go, but no, I haven’t tried. Always nice to hear from people that have had success with it though!