I have three cameras that will output huge 100MB+ jpg. files. The Sony A7r with it's 36MP from a 35mm / 'Full-Frame' sensor, My Nokia Lumia 1020 Smartphone with 38MP from a 1/1.5" Micro Sensor and My Sigma DP2 Quattro with a whopping interpolated 39MP from it's APS-C Foveon three layer sensor. Now it should be a forgone conclusion as to which produces the best image quality, but this post examines what each camera actually produces rather than just making the usual photographic internet assumptions.
First off, these are BIG flles and as you can see bigger than an A4 page and a 16MP camera file by some distance.
For this comparison I used my Sony Zeiss 35mm f/2.8 on the A7r. The other two have fixed lenses, so I picked one in the middle. The Nokia has a 25mm (35mm 'equivalent') The Sigma has a 45mm (35mm 'equivalent') First off here's a colour test.
Now what might surprise some is that the Nokia Smartphone produces the most accurate colour on auto white balance. I've noticed this (and my Blackberry phone is the same) that my phone cameras produce incredibly accurate colour. The Gretsch guitar is absolutely spot on and so is the red Stratocaster in the background. nteresting result which I have no explanation for.
In terms of sharpness and resolution at ISO 100 The Sony A7r is clearly the best. But then if it wasn't I'd want to know why!!! The 'full-frame' files are lovely and crisp. Again unsurprisingly the Sigma is better than the phone. But it's worth pointing out that there would be no problem in reproducing either image to very large sizes. Sigma claim medium format quality from their Foveon sensor, but I've always seen that as a marketing exaggeration. Even if I've got time to process the Sigma files from raw, the A7r still produces sharper results. The Sigma is very good, but the larger sensor still wins out no matter what Sigma might claim.
I should of course point out that the 4.1mm f/2.2 (fixed) lens on the Nokia phone does have softish edges and I often crop those out when I send files to stock libraries. However this is more noticeable when I choose the 16:9 ratio and the 4:3 I used here is usually better.
At ISO 800, which is the highest I'd ever use either the Sigma or Nokia unless it was an extreme emergency, the Sony is again the best. It's also interesting to se that the micro sensor phone produces a cleaner image than Sigma, though again that's no particular surprise. You will also see above that the Sigma meters lighter than the other two cameras as well. I can get rid of the noise by darkening the shadow areas, but I obviously loose detail as well.
Well this is no way a scientific test, but just a post to say that while what I would expect to have happened, i.e. that the Sony A7r has the best image quality, the other two cameras aren't that far behind. Both can justify their huge file size and none of my picture libraries reject either the Nokia or Sigma jpgs. on quality grounds. And it is the case that firstly differences between sensors are not as great as some would have us believe and secondly with careful post processing and sensible selective sharpening those differences are further narrowed.
That's not to say that if you want the best image quality in a non Medium Format camera, then the Sony is the obvious choice (Or the Nikon 810 which uses the same sensor) Of that there is no doubt. But then if you want decent images in an easy to carry fixed lens camera that doesn't cause a small earthquake when you press the shutter then the Sigma and Nokia are great carry anywhere cameras. And the Sigma doesn't produce the most accurate colour but for virtually everything I photograph it's my favourite.
And none of this tripod mounting testing takes account of how I can work with the cameras out in the real world, where the Nokia in particular comes into it's own. In terms of how I'm perceived when I'm using it, it becomes an 'invisible camera'. I'm just another phone snapper using that. As indeed I am with the Sigma, which is a slightly more 'unorthodox' shape, but still a camera nobofy takes any notice of. And yes the Sony is small, but it is noisy and people do notice that noise, which means in many situations it's less useful than it might be. Firmware update with electronic shutter please Sony!!
I've also left out any discussion as to whether anybody actually uses any of these 100MB+ files I create with these cameras and to be honest I really don't have any way of knowing that, since several of my libraries now sell all sizes at the same price, so people will obviously opt for the largest size whether they use it or not. And perhaps the most important image in this post is the one with the size comparisons. Because 99 times out of 100 these huge files will be downsized and probably about 50% of the time they will end up published on the web. And at those sizes it becomes virtually impossible to tell the difference between them.
But as I've written many times, the impression that a large file size makes is priceless and there is no doubt that many people still associate more pixels with a 'better' image. And no that's not actually the case, but if people who buy images perceive it to be so then I'm happy to go along with that perception. Bigger isn't always better, but bigger should be better or bigger must be better are widely held beliefs. And in the case of this test the bigger pixels and biggest sensor ARE the best, but camera technological development being what it is, that difference is no longer the unbridgeable gap that it used to be.
I received a comment on this post from someone who misunderstood the difference between MP's and MB's and who declared the whole post invalid because of that.
'Not too sure where the 100MB size came from!? Even the RAW files off the Sony A7R are only about 36MB. Puts a bit of doubt on the remainder of the review I would guess?'
I've decided to add this to the post just to clear up any confusion other people might have. For those who are well aware of all this, just ignore the following.
The Sony A7r produces a (full-resolution) jpg. that measures 7360 x 4912 pixels. 7360 x 4912 = 36152320. Hence 36MP. The size of the file produced however is 103.4MB.
The Sigma DP2 (in-camera) produces an interpolated jpg. that measures 7680 x 5120. 7680 x 5180 = 39782400. Hence 39MP. The size of the file produced however is 112.5MB.
The Nokia Lumia 1020 (high-res 4:3 ratio) produces a jpg. that measures 7136 × 5360. 7136 × 5360 = 38248960. Hence 38MP. The size of the file produced however is 109.4MB.
MP's (Megapixels) indicates the number of pixels an image is composed of. MB's (Megabytes) measure the size of the file when stored. However, jpg. and tiff compression can reduce that size. But for viewing and editing on a screen as well as for publication, the size in MB's indicates how big the file is.
The size of raw files when saved and stored varies with most cameras. Since this is raw unprocessed data and needs software to turn it into an image the size of raw files is smaller than the 'developed' image.
If you are still confused the following might help.
SUPPORT THIS SITE.
As a full-time photographer I make my living from selling images on Stock Photography sites. Writing this blog and doing the comparison tests takes time away from that and earns me very little. If you find what you read here of interest, then you can help me to fund the gear I buy to review, by clicking on the adsense banners, donating and / or buying your gear from the affiliate links. You don't pay any extra, I get a small commission.
Previously I was posting on the free, Blogger platform, but this site, with it's greatly increased functionality, costs me money and the more it expands, the more it will cost. If I can get THE SOUNDIMAGEPLUS BLOG economically viable, then I will be able to review a lot more gear and extend and expand those reviews. Running a blog these days that competes with the best out there requires a lot of time and effort and is close to a full-time job. This means that I'm neglecting other work to put that time in. It is my intention to turn this into a much more comprehensive review and user experience site and I can only do that if I can get it to generate more income.
This site, like much of the internet, has free content and like much of the internet is funded by advertising and donations. I realise that not everybody likes advertising, but without it many of our favourite sites would have to resort to charging for what they do. Google, Facebook and all the other social networks sites remain free because of that advertising.
There is an interesting article on the BBC website HERE, which deals with many of the issues above.