11/12/2014

The New Potential Of The iPhone Camera






This Pic of a WW1 Gin was taken in full sun with deep shadows, without HDR there
either be no highlight details or fully black shadows, ProCamera 8 does a great job
and the monochrome version here like nice tonally.

Over the past few weeks I have been exploring the new possibilites offorded to iPhoneography by the upgrade to iOS 8, and I have to say it is very impressive.

My wife and recently returned from an overseas holiday and it would have been terrific to have many of the new iOS 8 capabilities whilst away, alas iOS 8 came out whilst we were away and we were unable to upgrade due to net access (or the lack of it). In any case neither of us would risk an OS upgrade with the possibility of glitches when we needed to be 100% sure our mobile technology was working perfectly every day.

Since return I have in particular been playing with the upgraded built-in camera application and Photos, ProCamera 8, 645 Pro, and a new app simply called Manual.

All the apps have something different to offer, all are terrific, but as always no one app that can do it all, so I guess there is still room in the market for the one "killer application", ProCamera 8 probably comes closest at this point.

ProCamera, (in all versions) has long been my favourite iPhone/iPad Camera replacement app and with the upgrade further cements that, technically the new app provides a pathway to better photographic results and more efficiency in shooting.

I will post some reviews on these apps indivually but for this post I would like to explore just how the camera end of things are developing on the iPhone now that Apple have unlocked the ability to fully control the camera and also consider where these developments may take us.



HDR Version from iPhone 5S
Edited in Photoshop





Non HDR Version....(also edited for an optimised result,) the difference is obvious
especially the sky!


HDR

One aspect that has impressed me particularly with ProCamera 8 is the new HDR option, (which is a paid extra) I won't say it is perfect but its pretty good and easily allows you to capture a far wider dynamic tonal range than is otherwise possible with a single frame capture on a small sensor, in fact the tonality looks very much like what one would obtain from a full frame DSLR in terms of rendering usable highlights and shadows.  It is of course a multi-shot application so there is always the possibility of ghosting, I have seen that on a couple of occasions but overall the results are very nice.  My point is, a really good HDR implementation on the iPhone is the answer the main deficit of most mobile devices compared to DSLRs and Mirrorless cameras, an inability to render smooth highlight tones in skies and other bright objects whilst still giving some shadow detail. Remove that issues and the iPhone becomes a far more competitive tool for the average snap shooter.

Previous HDR options, including Apples' own Camera implementation are either a case of too little gained (Apple) or heavy handed and fake. The ProCamera can look pretty fake too if you choose to go down that path but generally you get very natural looking results, especially in monochrome.

When you consider that this is early days for iOS8 and the first version of this "in app" feature for ProCamera, we can assume that performance will only improve. 

One core advantage of Mobile phones and HDR is they all use an electronic shutter and due to the wide fixed aperture of f 2.2- 2.4 can shoot at very high shutter speeds  ( up to 1 / 40,000 in some cases I believe) under bright light, thus reducing the potential problems of ghosting because there is virtually no time gap between the indiviually captured frames. DSLRs and Mirrorless cameras generally have to reset the mechanical shutters and shoot at much slower shutter speeds making hand held options much less likely to succeed, ( though Sony have for years managed some super impressive HDR options in camera, especially on the NEX series.

Given further devlopment it is entirely possible the iPhone could render the dynamic range advantage of the DSLR null and void for non-movement shots, which for causual shooters will be another nail in the "do I really need to take a DSLR today coffin". "Note, I am not suggesting the image quality will be the same, but for most shooters that will be moot". 

Future improvments could come via faster readouts of sensor data, more intelligent shutter speed selections, better blending algorithms, and improved image stabilization on newer models.


Image Noise

Another oft quoted deficit of phone cameras is the higher levels of image noise as compared to DSLRs and Mirrorless, the physics mean that noise from small sensors will always be greater and especially under low light, but could it be made better?  

Of course it can. 

No doubt some the noise reduction will come via sensor improvements but another answer is image stacking and for a few years there have been rudimentary apps available for the iPhone that can capture multiple frames of the same scene and then average out the noise to produce a sharper noise free final files.  I have used these quite regularly and found they open up a whole array of possibilities.

The downside? 

These apps is need to be used with the phone on a tripod and the capture time means they are of no use with moving subjects, this by no means makes them useless, it just limits you to static subjects.

Technically there is no reason why image stacking could not be used for hand held capture if the readout speeds of the sensor were fast enough and the shutter speeds quick enough and importantly the alignment algorithms were smart enoigh to do the job to a high quality.  None of this is impossible, and I can vouch that even with the current apps a locked down iPhone stacking 4 or 8 identical frames renderes a virtually noisless image with much greater clarity, better tonality and lower noise. In practice the process is very similar to HDR, which we know works fine even now, but will one of the better camera replacemnt apps integrate this function any time soon, I expect so.


Resolution Increases

What about more resolution? Of course Apple could simply add more pixels, as other brands have done, but ultimately its a waste because the resulting files show little extra detail and far more noise, Apple didn't hold back on increasing the pixel count of the iPhone 6 and 6 plus because they couldn't be bothered!  

There is a way to increase the resolution of an image without adding more pixels, its called "pixel shift" and the idea is far from new.  There are two options, one, the sensor is mechanically moved by a very small amount whilst the camera remains fixed and 4 frames or more are captured which see fractionally different details, or two, the whole camera is moved by a very small amount and four or more frames are captured.

The secret is in the processing of the files. The initial donor images are uprezzed to a much larger size, say 50% or more and then the details are blended together from the 4 or more individual files.  

For years, there has been software around for computers for this super res trick, but as far as I know no iPhone apps have been produced, probably because the processing overheads are big, but now that iPhones are running much more powerful processors it should be possible.

In the longer term it should be feasible to blend HDR, multi shot NR and uprezzing into the one final frame!


Compression

One aspect of iPhones and other small sensor cams that I find frustrating is the damage caused by file compression, it is quite variable depending upon content and the selected ISO and most times it is too heavy handed, obviously this is to reduce files sizes and be better suited to integration with the iCloud and on-line sharing, but it sucks big time. The option to override the heavy compression levels or even save in tiff or some form of Raw would be brilliant.  Thankfully there are currently a select few camera apps that can save Tiff or control the level of compression, "645 Pro" being the prime example.  Will this become more commonplace, Yeah I am sure it will and certainly iOS 8 expands the possibilities. This feature will make it much better for photographers wanting to produce larger prints, post edit their shots or just be able to crop better after the event.



The ISO control

iOS8 opens up the possibility of controlling the ISO for the first time, for me that is probably one of the best changes. iPhones left to their own inclinations will like pretty much any fully automatic pocket camera seek to maintain high shutter speeds to ensure less movement blur whilst trading off the sensitivity. Often the iPhone can be supported in some way and thus could shoot happily at much lower ISO settings even in quite low light, so having control over sensitivity is a huge deal.  In fact I have made several test shots in low light with the ISO locked to minimum and the improvements in image quality are not trifling.  Again there are already several new apps or updates of established apps that have integrated ISO control options.


The Hard Basket

Alas some deficits when compared to your handy DSLR will probably continue to exist and frustrate you, in particular the lack of depth of field control, could this ever be addressed?

 I believe "depth of field" control is possible, but I remain convinced it is will still be a few years before we see a proper implementation of something that truly simulates the DSLR look. 

The answer to the problem is not adding the blur in post, which is both laborious and inconsistent and currently available via apps like "Big Lens" but rather changing the way the image is captured and internally processed.  

In theory if the phone were able to continuously vary the focus from very near to far and take several frames in a super fast sequence with tiny variances between the frames, it could be possible to map which bits are sharp in each frame and then combine the sharp or blurry bits accordingly into a single frame and thus simulate whatever DOF look you wanted. The nascent technology already exists in several forms, both within photo editing applications, shooting using manual focus stacking and also dedicated cameras used for micro photographic work. Additionally there is the still very novel light-field  "Lytro" cameras. But bringing it all together into a unified fool proof approach that works perfectly is a huge challenge and will no doubt require enormous processing overheads. Who knows perhaps the processing of the files could be cloud based, that could certainly give Apple a unique marketing edge?


Hardware

On the hardware end I think we are finally seeing some add-on lenses that actually might be worth the price of entry, with the new "Moment"ones actually appearing to produce some image quality that exceeds the "toy" rating. it is highly unlikely we will ever see truly telephoto lenses for the iPhone, or a brilliant super wide, but for most peoples needs a short tele and semi wide cover pretty much all bases.  The good news is that if the "Moment crew have been able to crack the quality nut then other makers should be able to build on their work to explore even higher levels of performance, in the end I guess is comes down to what are you and I prepared to pay for the privilege of increased optical options?

As an adjunct to the lenses it should be possible for lens designers to create custom apps to properly correct the inherent deficits of the lens post capture, just like most modern digital cameras do. At the present you would of course need to tell the device what lens was attached, but perhaps in the future the lenses could contain an NFC chip that talks to the camera to let it know what lens is attached.


To conclude

Will your iPhone replace your DSLR or Mirrorless camera, well not for me but I have no doubt that its envelope of application will continue to expand and I certainly use mine for a wide array of photo tasks and only see that increasing in the post iOS 8 world, which is a great thing as often I just want to carry my camera in my pocket!

09/12/2014

EVF Denialists Haven’t Got Clue


Precise framing in EVF can make a difference for many compositions, especially
those where lines just have to be in the right place.

Now that is a strong statement, some of you are probably already frothing at the mouth in anger. 
If you follow some of the better know photography forums you will no doubt soon come across a number of people who are almost religiously fervent in their denial of the use of EVFs.  These folk really get steamed up about the whole EVF thing and I have witnessed them pour acidic abuse upon others who have had the audacity to suggest that just perhaps the EVF might be the viewfinder of the future.

I am not going to be so kind as to beat around the bush, if you don’t believe the EVF is the future you are living in the past!

I think the denial is closely aligned to the eventual demise of the DSLR as we know,  many fanboys on forums are writing rabid claims that DSLRs is not dying because they still sell way more than mirrorless, this is a stupid line of argument.  Of course the DSLR is not dead, but they are toast so to speak , in the longer term anyway. The death and funeral is still quite some time off but the reality as I see it is “DSLRs are now a technological dead end”.  

Just because something still sells really well now does not mean it will not be replaced by something better, just have a chat to a Kodak rep (oh sorry they don’t exist any more) or check out the sales of old style Nokia phones, CRT computer monitor anyone......anyone want one?

As said I suspect part of this over the top state of denial, (and I believe it is denial), is fuelled by the deep down suspicion that should the EVF succeed the whole world will go mirrorless and their precious and expensive DSLRs and lenses will be ...well useless.

If you need any proof that change is afoot just check out what Sony have recently announced.  It seems there will be no new Sony DSLRs or SLTs, from 2014, all their interchangeable lens cameras will be mirrorless! Still using the same lens mounts as the current SLT models or e mount, so the lenses are safe and yours probably will be too, so lighten up.

Still, why people get so worked up over changes to technology that will likely render more than a few benefits for those who adopt said technology is quite beyond me, I guess some people really just don’t like change.  So what if DSLRs as we know them are rendered obsolete, if you currently own one and a few lenses I am quite sure it will continue to serve you well for many moons to come, nobody will force you to change, regardless of what happens.

The Optical viewfinder has been with us in DSLR form for a long time now, for many photographers it is all they know.  In my instance I bought film cameras in the past on the basis of the excellence of their OVFs, this was always important because most of my film cameras were not auto-focus, a bad OVF simply meant out of focus shots!

My personal experience has been that since the advent of DSLRs, very few have had OVFs that matched the quality of those on the really good quality SLRs of the past. The one definite exception that springs to mind being the OVF on the Sony A900, which is truly marvellous, but still, it’s no better and perhaps a bit worse than say the film era Minolta Dynax 7, which is actually its spiritual forebear.

I promise for those of you who have only been in the photography arena since the advent of digital, you probably do not know how good a really good OVF can be unless you have a high end DSLR.  Most DSLRs, and especially APSC versions have OVFs that frankly are like looking down a somewhat darkened tunnel, and even some top drawer Full Frame DSLRs have been less than spectacular.  Why would you not want something better?

The modern OVFs are designed to work with Auto-Focus which means the focusing screens are not ideal for manual focus purposes, for most users this matters little, but it does change the demands placed on the OVF.  In the modern age an OVF is really to facilitate a view that makes for easy framing and composition, not precise focus.

As said an OVF can be truly excellent, past high end film bodies attest to this, but great OVFs are actually very difficult to build and add significant cost to the construction of the camera. Ultimately the OVF has persisted into the digital age because the early EVF technology was not yet developed enough to offer a viable alternative  (actually they were crap) and perhaps just as importantly OVFs have been maintained “out of tradition”.

To make sense of this rabid EVF “no good”, OVF “for ever” debate I think it is time I actually had a really good look at the benefits/deficits and practicalities of the two options.

Up front I want to make a couple of personal points that might give you some insight into my approach.  And...before anyone starts flaming me by saying “you just don’t appreciate a good OVF”, forget it, I own a Sony Alpha 900 and have shot thousands of images for a living on it, the A900 has one of the best OVFs money can buy in my humble opinion, heck you can even change the focusing screen type.

Most of the entrenched OVF adherents conveniently forget about one core issue when presenting their arguments. These “fixed minded” photographers present claims that include, the EVF is too slow, too blurry or that it has a number of other core problems, all without acknowledging that the EVF has developed enormously in the past 10 years and has rapidly accelerated in R and D in the last 2.  EVFs will continue to rapidly develop over over the next 5 or so years, todays EVF is not tomorrows EVFs, and any judgements about how the EVF will effect camera design, usage and form factors needs to accept the certainty of rapid continued development.

Secondly the OVF has for a long time been fully mature technology that is actually going nowhere new in terms of development, it is highly unlikely to radically or even incrementally improve...in fact it has got worse for many mainstream cameras as compared to later film age DSLRs.

Third, whilst people get really worked up about the viewfinder, let’s be clear, it is called a “viewfinder” for a reason.  It is not your end result, it is there to help you frame, compose and adjust the image (the last does aspect not apply to OVFs).  The viewfinder image will be gone as soon as you take your eye from the camera, the image you take with the camera however will perhaps last forever.

Photography is not about looking through camera viewfinders to see the world clearly, for that we have our own eyes, spectacles, binoculars and if you want to be very specialised movie makers “eyepiece” viewfinders.

I suspect there is also a unspoken driver in the fury of all these rabid EVF denialists, deep down they know that should the EVF triumph, their particular beloved brand will be seriously impacted  and shaken from its perceived current “state of power” at the top of the DSLR tree.  Yes indeed pretty much all the denialists are Canon or Nikon fanboys, and so far neither company has done or even looks like doing anything really serious about implementing high end EVFs into DSLRs style bodies. Yes Nikon has the “1” series but that’s not a serious DSLR market competitor and Canon have......oh hang on while I have a look in the cupboard, Oh yeah thats right....nothing at all.  (there are rumours they will, but I suspect they will probably remain just that)

But panic not, unless Canikon are silly enough to follow Kodak into the digital abyss they will go eventually go EVF too, I expect they are just waiting for someone else to solve all the problems first, neither Canon or Nikon are what you would call truly innovative these days, they are the mature traditionalists in the camera world.

Now moving on, what I want, and I imagine most keen real world photographers want, is a viewfinder that allows me to frame and compose the image and determine how the actual recorded image will look at the same time.  The OVF does the first 2 fine, but is completely and utterly useless for the later.

So now having got that off my chest lets explore the world of EVF vrs OVFs.

OVFs can and often do offer a nice crisp bright image of the scene you are focusing on and a good one can facilitate fast manual focus.  The scene in the viewfinder looks pretty much like it does to the unaided eye and a really good one won’t suck up too much of the available light either.

OVFs perform really really well with telephoto lenses, the tele lenses magnification makes it very easy to see the image pop in and out of focus, in fact I find it quite entertaining.  As we go wider in focal length the OVF becomes far less suitable for manual focus and once you get to around the 24mm equivalent setting even the best of eyes and a top drawer OVF will still have difficulty determining precise focus.  Personally I feel the inability to precisely nail focus at wide angle settings is a massive failing for OVFs, a slightly out of focus wide angle image usually just look soft and fuzzy all over, it has no redeeming grace at all as far as I am concerned.  How many times have you shot with a wide angle, thinking the image was in focus only to find that once opened on the computer it is just plain fuzzy?  Thought so.  The problem is compounded because wide angle lenses, and especially zooms at the wide angle end of things are terribly touchy in terms of precise focus, just being out by the tiniest degree of rotation on the focus ring renders complete disaster.

Telephotos, and especially those with an even moderately fast maximum aperture present no problem to manually focus, even with a half baked APSC train tunnel finder.  Then again such lenses present very little challenge for any auto focus systems either.

On the other hand AF systems will often stumble on wide angle shots, especially if the contrast is low or there are few distinct edges in the image and of course throw in dim light and things just get worse.  Truth is, just when you really need that AF, it gives up the ghost, not always of course but more often than is desirable.  If you think the AF will save you every time, just try this little experiment, frame a scene up at the wide end of your lens, let the camera focus and then snap of the shot.  Turn the camera off and then on again and repeat the whole process a few times.  I hazard a guess that if you will find that some shots are indeed sharper than others despite nothing supposedly being changed.  Trust me for rock solid focus accuracy with really wide lenses you need something a bit more sophisticated than an OVF and Auto Focus.

An ultra wide angle lens, say in the 10-15mm range can be particularly difficult to focus and in fact can be out of focus by an enormous degree before one even notices in the OVF, actually even when using magnified live view it can be more than a little difficult.  And no......just relying on the greater DOF available is not enough to resolve the issue.

One little feature EVFs can offer, but OVFs never will is focus peaking.  It is actually a child of the video world.  Focus peaking draws a coloured outline around the details that are actually in focus, (the colour can usually be changed to suit your needs), this feature makes manual focus very snappy and can also help to confirm what exactly is in focus when AF systems are used.

There is also a related EVF only option of Zebras which does for exposure what Peaking does for focus.  Zebras allow you to precisely judge where the highlight tones are clipping and that clipping point is usually settable.  Zebras are far more useful than the Blinkies of the past and also more useful than a live histogram (which is yet another thing not available in the EVF.)

DSLRs all have some focus error, no matter how much they cost.  It’s simple really, unless the viewing screen and sensor are absolutely perfectly aligned you will get a focus error because it looks to be in focus on the screen but the projected image on the sensor may well be falling a little in front or behind the sensor.  This issues does not show up much with low res cameras but with todays hi res DSLRs that little variation in manufacturing tolerance can and does knock the edge of your images potential clarity.

An OVF on the other hand derives its image direct from the sensor itself, there is simply no way an image that appears in focus on the EVF cannot be truly in focus.

Few DSLRs have viewfinders that show 100% of the recorded view, generally it is somewhere between 88-95%, which may not sound a big deal, but for those seeking to fully optimize their compositional arrangement that may be a little annoying.  Of course better to show too little than too much and then have details go MIA.  The EVF of course shows 100% of the scene, you get what you get!

Perhaps the greatest failing of OVFs is that you have absolutely no idea about the level/quality of exposure by looking at the image on the screen, your ISO, aperture or shutter speed could be way out, but what you see in the viewfinder will not change one iota to reflect those incorrect settings.  Hence exposure mistakes can be very easy to make with an OVF.  Of course even the most basically experienced shooters are well aware the exposure and the OVF bear no correlation, hence photographers are forced to take their eye from the viewfinder once the shot is captured and then press the review button to have a look at the image as displayed on the cameras rear LCD.......how quaint, how 1990s!

An EVF by comparison, can and usually is, set to reflect the settings enabled on the camera  If your exposure is off, it’s pretty obvious, “before” you press the shutter!  Of course once you have taken the shot, you can if you desire look at the image without removing your eye from the viewfinder.  This has two benefits, first in bright daylight it is easy to see the image and secondly it is far quicker than removing the eye from your camera and then pressing the review button (unless the auto review time is set to more than a couple of seconds).  Regardless, it makes for a far more seamless level of operation.

The OVFs can of course display the cameras settings at the bottom of the screen, but these settings cannot be overlaid over the image and in many cases I find people don’t even notice the settings hiding there in the bottom of the viewfinder.  

An OVF cannot be zoomed in to make it easy for you to manually check focus or indeed for you to manually focus at all and nature has not seen fit to provide us with zoom eyeballs!  Naturally an EVF can be zoomed in, often to around a 15X view which makes pinpoint focus accuracy in manual a skip in the park, and you can normally move the focus point to anywhere on the screen, including the very far corners which can be useful when working with really wide angle lenses or trying to accommodate field curvature.

Ever had white balance problems, don’t worry all of us have.  Your EVF will not help you with this at all, your colour can be totally out and again just like exposure your view through the OVF will not alter one bit, relegating you yet again to the rear LCD.  But just try accurately gauging colour on an LCD screen in bright sunlight, not too easy I can promise.

Of course extending on from colour we have a whole raft of other variables, like contrast settings, saturation levels, hue adjustments, sharpening, tones curves and more that are not in any way able to be judged using the OVF, and unless you are using live view on the LCD, absolutely have to be judged after you take the shot.  

I am pretty sure that to future shooters that fact that we worked this way is going to sound almost dumb, in the same way that digital shooters often consider the thought of shooting film without a way of seeing the image captured as being more than a little odd and limiting.

But wait there is more, what happens when the light does what it is prone to do....disappear.  Well using your OVF equipped DSLR the image is going to get pretty dark and you will soon reach a point where you simply cannot see to compose.  A good EVF will also get a bit harder to see, but usually you can deal with much darker scenes before it all goes pear shaped because the on screen image is gained up, and while the EVF image will look pretty grainy, the recorded image will be fine.  Meanwhile with the OVF......well you just can’t see anything!

Ah but you say, my DSLR has a depth of field button, so I can stop the lens down to see what is in focus before I press the shutter, how cool is that!? 

Sorry dude, not cool at all, first if the light is not very bright that stopped down view is going to be pretty difficult to see properly, but more importantly it is very difficult to focus manually with a stopped down view unless the OVF is very very good.  

With an OVF you normally focus the lens wide open and when you shoot the image the aperture stops down...so what you say!  

Well the focus can actually shift with a lot of fast lenses as you stop down, yes you heard that right, as the lens stops down to make the shot the critical focus point is no longer where you thought it was.  To help get around this modern DSLRs have all sort of internal tricks to try and game the system and overcome the problem but nonetheless they are nowhere near perfect.

An EVF gains up as the aperture is adjusted to a smaller setting, this means you can and usually do, focus and shoot at the same aperture, thus it is easy to see the full effect of DOF unless you are shooting in really poor light.

An OVF performs its old school magic of enabling you to see the image before capture by dint of having a mirror in front of the cameras sensor, thus making the camera a “DSLR”.  But that mirror comes with a few costs attached, for me the most problematic one being the mirror adds vibration to the image capture process.  By my estimation from tests I have carried out the loss of the mirror can enable mirrorless camera images using an “electronic first curtain shutter” to be captured sharply at a couple of shutter speeds slower than a DSLR. The absence of the mirror also has a flow-on effect on the clarity of images in the range where they may become nominally soft using a DSLR, typically in the 1/30-1/125 range.

Finally there is a little rarely mentioned issues with OVFs, form factor!  You simply must design a camera in such a way that the viewfinder is in line with the lens and sensor, hence the shape of the camera must be that of a DSLR.  No problem you think.?

What if the viewfinder could be to the right or left side of the camera body, that might make things a bit better ergonomically, you may even be able to keep those greasy face prints of the LCD and stop squashing your nose into the bargain.  

Here is something for history buffs, did you know that film age high end SLRs had removable viewfinders, that’s right, you could change the viewfinder to suit the job, want to do a spot of macro work, use you camera for waist level work, no worries just change the finder.  Does this option exist in the digital age?  Nooooo, not unless you have enough of the folding stuff for a medium format rig. 

But here is a thought, some EVFs can actually be tilted to provide angled view options including being able to look down into the viewfinder from above which I can tell you is pretty damned cool for macro work.

In all of the above areas the EVF utterly creams any OVF out there, frankly I think anyone attempting to argue differently is either totally unaware of the way things work or is in EVF denial, so just where then does the OVF score?

Mainly the OVF gives you a sharper clearer view under fair to good light conditions and enables a camera to use a focus system that is normally faster and perhaps a little more accurate (assuming the mechanics of the system are perfectly aligned).  Currently those folk who regularly shoot sports/action will be better served by a DSLR, they are far more likely not to miss shots due to mis-focus and focus tracking issues.

The OVF also can provide a very pleasant view, so if your prime purpose for owning a camera is to experience the world through a viewfinder......buy a DSLR.  But if you actually want to take photographs with the camera maybe an EVF will be better

Ok then, then, there must be downsides to EVFs, surely there are downsides, please tell there are downsides.....I just bought a DSLR.

Yes there are.

At present EVFs as indicated are not as sharp to look through because in the main they lack enough pixels to be truly truly crisp.  But in just a month or so Sony will further increase the resolution by about 25% so I reckon judging on how good the current state of the art EVFs are that will be pretty close to ideal, game over for that issue.  

More importantly within a couple of years almost all EVFs will easily have more than enough resolution at the current rate of development, even cheap ones. I’d assume it will take another 3 years for EVFs to fully match the OVFs resolution, but it will happen.

Next up current EVFs tend to make it hard to really see the details in the shadows before you shoot, an OVF has no problem here.  You can work around this by changing the cameras JPEG settings to a lower contrast option (which is what I do) but nonetheless it needs to get better than this to pacify the OVF apologists, I am sure it will and within the next year or two..

Similarly some EVFs don’t play nice with highlights either, but again it is easy to jig the system by adjusting the JPEG contrast back a bit, which truth be known, for most folk would render an image that is far more printable and editable.  Looking at the screen technology used on the high end smart phones such as the Samsung Galaxy S4 you can see the promise of a solution, again probably this will take another 2 to 3 years.

EVFs use more battery power, and since they are usually used in smaller cameras with smaller batteries to start with you normally only get somewhere between 250-400 frames per charge.  For me it is pretty irrelevant, I have bought extra batteries, but I have to say some armchair forum experts get really worked up over this one, apparently the shorter battery life alone means the only way to go must be DSLR. Which I might add is pretty dumb way of looking at it, a mirrorless camera and 4 batteries will still be lighter and take up less room than a DSLR, I just slip an extra battery in the change pocket of my jeans, hardly a deal breaker!   

Will battery life get better, maybe, but I imagine as larger mirrorless cameras hit the market with bigger batteries the issue will fade anyway.  As an aside Sony SLTs use an EVF in a DSLR sized body with a bigger battery of course, and they certainly can shoot quite a lot of shots before the bunny runs out. 

A  real failing of EVFs is tearing. This occurs when you are shooting sport and attempting to follow action, the image sort of breaks up, messy really.  Once again if sport is your bag, I would say the EVF is not yet ready for prime time. I think this one will take quite a while to sort, though it seems Sony have almost got this fully nailed with the current RX10 so perhaps it won’t be a problem for long.

So that’s about it I think.  I have not ventured into the realm of video purposely, let’s just say this, unless you want to use auxiliary finders and other add-on stuff, for video the EVF is the only way to go, unless you actually like the “stinky nappy handhold used whilst looking at the LCD style of shooting”!

So now, I have donned my fireproof suit, chainmail armour and protective goggles, attack at will, you won’t change how I feel about such matters.

The EVF is not perfect but even now it is a better choice for me anyway and soon it will be virtually perfected. The OVF will never be better than it is now and in the balance the downsides are just too great when you are actually taking photographs, rather than looking through viewfinders.

Let me just leave you with this, I bought my last DSLR over 4 years ago (and recently sold it), there is zero chance I will ever buy another one.  I have since fully committed to mirrorless and when (not if) a pro camera comes along (the Sony A7r is close but still no cigar) that addresses fully the remaining small issues related to EVFs I will be lining up with my hard earned cash.  In the meantime I use my Pro DSLR for about 60% of my paying jobs and my mirrorless camera for everything else including all the personal shots not taken on my iPhone.