Saturday, 28 May 2016

modern Phones as cameras

I recently bought an Oppo F1 phone (yes, the selfie expert ... what a wanking name) and found out that the camera is actually stunning, but at the same time I doubt that the pictures on the OPPO site were taken with it. This has led me to revisit what I already knew: pixel counts aren't everything (but they are something).

So this is kind of a review of the Oppo F1 camera ...

Oppo F1 has 13Mpix - So things should get better right?

One of the things which drove my decision to purchase this phone was because I strongly believe in the philosophy:
the camera you have with you is the best camera you have
while I don't always have my Panasonics with me I pretty much always have my phone with me. This is not to say that I'm trying to find a substitute for my Panasonic, but just to make what I have better.

So with that perspective in mind I thought I'd gradually over the course of time add my findings on this phone.

A criteria I've had on phones for some time is to have one which does RAW output, because I've said for over a decade (nearly 2) now that what really hobbles cameras is the crummy JPG software they provide. I've often said that the camera should just capture enough of a JPG to show you on the back screen (cos you don't want to raw convert every time you preview) and just store the RAW, which we can then process (if you like, as part of the transfer to your PC even).

The Oppo F1 stashes its RAW file into a DNG format, which is very tidy thank you because almost every raw converter on the planet reads that. So despite the fact that few people really make much of it DNG is indeed more of a standard than any particular cameras chosen RAW format. Thus the Oppo loomed on my horizon.

After a few quick snaps and looking at them on the phone I was already of the view it was a fine phoneCam. So I thought I'd start comparing the F1 to my Panasonic GF1, which some may argue is inferior to modern m43 cameras. However I've shown earlier using RAW demonstrates that all that has really happened in m43 (and all cameras really) is simply an increase in on camera JPG processing and more pixels).

I found that the Oppo F1 has an angle of view which is close to a 28mm wide ... which isn't bad for a scenery camera. So lets look at some "sunny day" stuff to see how the Oppo performs in "ideal conditoins".

Yesterday was a mixed weather day, but with no actual rain (despite the look) and so from my balcony this is the shot that the Oppo got

First, the good news


Overview with JPG



then what I was able to do with the DNG


anyone with much editing experience knows that you just can't rescue tonals like this out of a crummy JPG like the one above. So thats quite impressive.

Still, lets look at some details.

First the 100% view around the middle of the JPG


then the 100% view of the image from the DNG


well bugger me ... you ask for some Brie with your Red wine and you get a stick of chalk!

So what looks ok on the phone screen doesn't bear resemblance to what you can get out of the actual camera.

FFS Oppo, why are you shooting yourself in the foot with this camera by using such a lousy JPG engine ... its simply shameful and insulting to the engineers who made it.

Ok ... lets have a look at what my GF1 with the Panasonic 14-45mm lens on it gave

Overview


100% pixel peep:


You will really need to open them side by side to see the differences between the Oppo F1 DNG and the Panasonic ... So the GF1 has a few extra bits of tonality and nicer details but you know ... if you weren't printing a show piece (and were resizing for the WWW) then the Oppo F1 image would do just fine.

Now the bad news

As well as having an idiot do their JPG engine, Oppo's DNG has a few problems of its own.

I first loaded the DNG into my ACR and was stunned with how shitty the image result was;


I tried mucking with the obious settings and it still sucked and so naturally I tried a few other options like RawTherapee, Photomatix and finally my old turn to command line 'dcraw'

Well bugger me dead but when put into "verbose" mode dcraw highlights what I believe to be the problem:

C:\temp\phone>dcraw -v -T C:\temp\phone\IMG20160527084439.dng
Loading OPPO     F1f image from C:\temp\phone\IMG20160527084439.dng ...
Scaling with darkness 64, saturation 1024, and
multipliers -1.#IND00 -1.#IND00 -1.#IND00 -1.#IND00
AHD interpolation...
Building histograms...
Writing data to C:\temp\phone\IMG20160527084439.tiff ...

Somehow the DNG file contains data which is corrupt or unreadable by my converters ... given that I've not had this problem with any DNG file I've ever had before I wonder if someone at Oppo is not following the correct file format for DNG ... or has skipped what they thought to be an irrelevant point (which clearly isn't).

So, when I produced a TIFF with these settings (some ball park scaling factors of the Red Green Blue Green channels)
C:\temp\phone>dcraw -v -T -r 2 1 1.5 1 C:\temp\phone\IMG20160527160051.dng
Loading OPPO     F1f image from C:\temp\phone\IMG20160527160051.dng ...
Scaling with darkness 64, saturation 1024, and
multipliers 2.000000 1.000000 1.500000 1.000000
AHD interpolation...
Building histograms...
Writing data to C:\temp\phone\IMG20160527160051.tiff ...

I got the above results.

So ... the Oppo can produce some fine results, but pretty much noone else is going to see them because:

  1. few play with RAW
  2. fewer understand RAW processing well
  3. fewer still are as command line approach

So Oppo, stop hiding your camera under crappy software and perhaps you'll get some better reviews than you find when Googling for Oppo F1 review. Almost everyone comments how the camera is "ok for the price" when in reality its a bloody good camera hobbled by (either) the wrong people doing the job or not giving them any time to do the job.

Not everything comes down to good hardware, although that's a start for sure.

I'll leave you with a final image comparison, this was taken in my garage with the sun setting, The light streaming through the windows is actually only an indicator of how dim it was. In there

The JPG overview


the center @ 100%


you can barely read any of the text on that box, and the bricks seem to have no texture, yet the same segment from the DNG processed as described above:


You can read the larger print on the box and you see that the bricks do have a texture.
Speaks for itself really ...

So come on Oppo, this can be fixed with a simple update to "Expert Mode" package on the phone. I recommend you do it (or someone does).

PS:other software

ACR 9.1 on Photoshop CS6 did a better job of the DNG file, as indeed did Snapseed, so my comments about tint are less applicable on those. However all other aspects after conversion were the same (and lets face it, the DNG was head and shoulder better than the the JPG).

Also, Snapseed does a fantastic job with the Oppo F1 files

1 comment:

Yu-Lin Chan said...

That's quite amazing what difference jpeg and RAW makes. It's a shame majority of phone users are happy with the picture quality, while they could demand better.