ProPhoto RGB vs JPEGs

Most common photo editors – e.g. Lightroom – let you choose the colour gamut to use for exported photos.  In Lightroom (at time of writing in January 2018) you have a fairly short list, of today’s common options – sRGB, Display P3, Adobe RGB, and ProPhoto RGB.  Since we’re all obsessive nerds, that we’re given an option dictates that we must make an explicit choice.  More pragmatically, the default in Lightroom – and many other photo editors – is sRGB, which is the one option that’s definitively wrong, so in this case you really do have to change it to something else, if you care about image quality at all.

So, what should you choose?  Well, obviously you want your exported photos to maintain as much of the colour gamut they contain as possible, and as accurately as possible – as part of the general principle that you want it to be the highest quality and as close to what you see on your screen as possible.  Modern digital cameras are capable of capturing far more than the sRGB space, and modern displays are also capable of larger gamuts too (typically Adobe RGB or Display P3, at time of writing, if not the union of both).  Thus why sRGB is unequivocally the wrong option (and any purported counter-arguments about colour calibration issues in web browsers and so forth are moot, because all decent web browsers handle colour management correctly & intuitively, and anyone not using one of those browsers clearly doesn’t care about a lot of things, least of all colour accuracy).

So then it’s just a question of which colour space is bigger, right?  That’s easy – ProPhoto RGB is huge.  A complete superset of all the others.  It actually encompasses colours that don’t even exist as far as the average human is concerned, because they’re outside our visual range.  So just use that, right?

Yes.  Maybe.  It depends.

The thing is, if you increase the colour gamut you encode your image in, you reduce the precision of your colours, all other things being equal.  Because you’re taking e.g. 8 bits, so 256 possible values, and spreading them out over a wider spectrum.  Thus each “bucket” – digitally quantised colour – is going to be bigger, coarser, and have a wider margin of error.  What this can mean in practice is visible banding in images which “should” be higher quality, because they have a much bigger colour gamut!

Larger colour gamuts really need correspondingly larger bit depths, in order to avoid sacrificing colour accuracy (or in plain terms, to avoid visible banding or posterisation).

Thus, if you’re exporting as ye ol’ JPEGs (an image format that’s just not very good, though it’s had a good run at over twenty-five years old at this point) where you’re stuck with 8 bits per pixel, it’s probably a bad idea to use ProPhoto RGB.  It’s too likely that in practice you’ll see nasty banding.  Instead, you’re probably better off striking a compromise and choosing either Display P3 or Adobe RGB, which aren’t so much bigger than sRGB that banding is often more visible, but are fully representable on many contemporary displays.  In theory as displays get better – i.e. wider gamuts – you’d want to upgrade, but in reality JPEG should be long dead before we get the next significant jump in real-world display gamuts, and their successor format(s) will undoubtably support much higher bit depths, eliminating this trade-off.

On the other hand, if you’re already exporting in modern formats – e.g. HEIF – where 10-bit (or better) bit depths are supported, you can consider extra large gamuts like ProPhoto RGB (just make sure you then use greater bit depths, as HEIF also supports 8-bit channels, and some software will still default to that).  It becomes more of a question of your target audience, your expectations for the longevity of that particular rendering of the photo, etc.

And if you’re using 16-bit colour depths, such as are options for TIFFs or other typical intermediary formats (e.g. when going from Lightroom to Photoshop, or vice-versa), then ProPhoto RGB is the best option, because there are no practical downsides.  Today ProPhoto RGB probably far exceeds the colour gamut your camera(s) can actually capture, but that’s okay – your camera(s) can probably capture more than just Adobe RGB or Display P3 too, and with 16 bits per pixel you’ve got plenty of colour resolution, so why sacrifice your camera’s capabilities?

Addendum

This still leaves the choice of Display P3 vs Adobe RGB, for your typical web (etc) exports.  I’ve been using Adobe RGB myself for a long time, since that was basically the next step up in displays for the longest time.  However, since Apple has delivered Display P3 to the world, Display P3 almost overnight became far more commonly supported in the real world.  Remember that any modern iPhone, iPad, or iMac supports Display P3, and most quality standalone PC monitors do also.  There’s also an argument to be made that it is a more practical expansion on sRGB, since it increases not just your greens but also your reds:

sRGB vs AdobeRGB vs DCI-P3
(image courtesy of Smeterlink on Stackexchange)

Keyboard autocompletes

Apparently if you get bored enough you start just playing with the keyboards installed on your iPad.  Those that have the suggestion bar at the top can make some interesting ‘poetry’.  You just keep tapping in the same place, or in some simple pattern across the N suggestions.  Some are just bemusing drunk gibberish, but some are actually almost insightful.  For example:

Microsoft’s “Word Flow”:

  • I have to be a good day and night and day and night and day and night and day and night and day and night and day…
  • I’m going on with your friends are for convenience and the rest in the morning to the public health care system and a few minutes and a few minutes and a few minutes and a few minutes and the rest in the morning…
  • I think you are not responsible for any other person in my life.

Apple’s built-in keyboard:

  • I’m not going home after a while but I’ll probably get home and go to get home from home and work on a Friday or just for the next few days hope I can be a bit more fun with you and you can get me some good morning text.
  • You don’t get a chance but they have the right hope that your team will have you back.
  • I’m not a fan of a good day but it has been a bit fun and I have no hope for any reason.

CASE Remote limitations

Here’s a list of things that are missing or otherwise dysfunctional with the CASE Remote.  Why am I only covering what’s missing?  I guess because, after using it for a while, it really does seem to be defined by what’s missing or broken, more-so than what it can do, which is relatively little.

Though I don’t have first-hand experience with other wireless camera controllers, it seems pretty obvious that most of the competition offer far more functionality (particularly the CamRanger, but also things like Timelapse+, Promote Control, etc).

Focus

  • No tap-to-focus.
  • Finest focus adjustment step is still very coarse.
    • I’m not sure if this is a limitation of the CASE Remote, its app, or the camera itself.  In any case, the focus adjustments are just too large for macro photography.  Combined with the lack of tap-to-focus, completely remotely controlled macro photography is basically just not an option, even for single stills let-alone focus stacking.
  • Nine frame limit to focus stacking.
    • Not nearly enough for many uses, and of course far fewer steps than the lens is capable of.
  • Contrast-detection autofocus only.
    • Not surprising, but disappointing as contrast-detection autofocus is much slower than phase-detection, less precise, and sometimes less accurate.  [Yes, really.  I’ve tested it.  Repeatedly.  I know this goes against conventional wisdom.]
  • Cannot disable autofocus [with the app] in timelapse mode.
    • You can of course disable it with physical switches on the camera or lens, if you can still physically reach your camera during shooting.
  • Cannot rapidly adjust focus.
    • There’s only one pair of forward/back buttons (as opposed to several with differing step sizes), and you have to tap for every step – you can’t just hold down on either of them.

Live view

  • No way to zoom live view (e.g. to see 100% previews).
    • On an iPhone this makes it especially pointless, over the camera’s built-in LCD.
  • The “shots taken” counter is frequently completely wrong (e.g. I’ve taken several dozen just now, and for some reason it still says seven).
    • Maybe this is supposed to be showing something else.  I can’t imagine what else, though.
  • No live view during timelapses.
    • Not even to show you recently recorded shots.

Image review

  • The Auto-download setting doesn’t work.
    • You still have to go to the ‘Explorer’ tab, click the ‘Camera’ sub-tab, tap every single image individually, and then hit the download button.
  • In the ‘Camera’ tab, sort of the “live view” tab, it shows thumbnails of the last images recorded.  But only sometimes.  And when you tap on them it shows you only a slightly larger, but still small, thumbnail – no way to zoom in or otherwise view the full size image.
  • Doesn’t support viewing RAWs (only JPEGs).
    • It claims to download RAWs to the controlling device, but will only show an extremely low-resolution thumbnail of them.
  • Doesn’t show full-size images.
    • They appear to be limited to something like 2048×2048, if I had to guess.  I’ve seen this problem in other image viewing iOS apps – it might be somewhat intrinsic to iDevices.
  • Downloaded images are shown in random order.
    • This makes it especially difficult to review the results of focus stacking, where you need to verify that key parts of the image are in sharp focus in at least one of the stacked shots.
  • Image download is sluggish.
    • Admittedly I haven’t used other wireless solutions, but combined with the app’s general lack of responsiveness, it’s overall quite tedious to use.

General bugs and rough edges

  • Settings adjustments often don’t take.
    • e.g. changing the ISO frequently doesn’t work – it just immediately reverts back to the prior setting (with a particular affinity for Auto, for some reason).
  • Can’t adjust key settings on the camera, like exposure delay mode (and duration) or long-exposure noise reduction settings.
  • Alternates between PC mode and camera mode seemingly randomly.
    • In PC mode you can’t adjust anything on the camera itself – including vital settings that you can’t otherwise control through the CASE Remote app, like exposure delay mode.  I actually get why it might need to use PC mode, but that it does it seemingly randomly makes it frustrating, because sometimes I can adjust settings, and sometimes I can’t, with no apparent rhyme or reason.
  • App is generally slow and awkward to use (on an iPhone 5 or iPad 3).
    • It’s very modal – it locks up during many operations, including key ones like taking & downloading photos.
    • It likes to display redundant modal dialogs, such as telling you that it’s downloaded the image you just bloody told it to download.
    • No progress bars or similar indicators for any operations.
  • Focus adjustment arrows have no indication of direction.  i.e. towards or away from the camera.
    • This is especially true in the focus stacking settings, where your options are +3, +2, +1, -1, -2, -3.  Huh?
    • And for what it’s worth, in live view mode ‘right’ apparently means closer to the camera.  Personally I find that the opposite of intuition.
  • There’s an item in the ‘Camera Settings’ menu (not to be confused with the ‘Settings’ tab) called ‘AEB’.  Tapping it does nothing.
  • Changing the Drive Mode setting has no apparent effect.
    • It certainly doesn’t work to enable mirror-up mode.

Missed opportunities

  • No GPS tagging.
    • Though I normally use a dedicated GPS dongle on my camera, with the CASE Remote connected that’s a little awkward, as they both prefer to be hot-shoe mounted.
    • The CamRanger can do this, for example.  Though it will only tag JPEGs.
  • No wireless network bridging.
  • No bulb ramping – or adjustments of any kind – to exposure parameters during timelapses.
  • No “bulb mode” – i.e. no exposure times beyond thirty seconds.
  • No video functionality at all.
  • There’s an “Add New” button under the ‘Features’ tab, which just throws up a modal dialog saying ‘New features will arrive soon’.  What’s the point of that button to begin with?
  • Cannot change shooting mode (P, A, S, M) using the app.
    • You can change it on the camera using the physical mode dial, and the app will (eventually) realise and update appropriately.