Are any of the Droid X/iPhone 4 camera photo comparisons legit?
I'm not a conspiracy theorist. Honestly. When I took a quick glance at the Is the Droid X camera really this bad thread, I conceded based on the visual evidence in the links throughout that thread that the iPhone 4 seemed to have a better camera overall.
Then I wondered: were the tests fair? It's easy to find out.
I saved the highest resolution photos (the original photos, in other words) from the sites with their own photos in that thread as well as a few others comparing the iPhone 4 and Droid X cameras, and the results were, to say the least, "interesting". (by the way, for those that don't know, Exif data is the data your camera puts on the image that lists all the settings of the camera at the time the picture was taken)
1st site from the other thread: iPhone 4 Camera Against the World - a set on Flickr
I saved the full-size versions of the first two photos on there. Both had virtually all Exif data stripped, and the only things on there for both photos were dimensions, DPI and bit depth. So we can't tell what bias exists, if any. The file sizes were very similar (124KB for X, 117KB for iPhone) and the aforementioned settings were the same. (375X500 pixels for X, 374X500 pixels for iPhone)
2nd site from the other thread: Still Image Capture, iPhone 4 v. DROID X (Updated) Boy Genius Report
I saved the full-size versions of the first two photos on there, the tomatoes, (also note they took 6 megapixel photos with the X instead of the full 8 megapixel size it's capable of, may mean nothing, may mean something) and they are taken at different aspect ratios. The Exif data remains intact here, which is good. The X pic is 641X361 pixels and the iPhone pic is 641X479. The ISO speed on the X is 100, and the ISO speed on the iPhone is 80. The lower the ISO speed, the higher quality a picture is because it literally spends more time taking the picture, allowing less light in. Evidence of this is the exposure time on the X (1/569th of a second) compared to the exposure time on the iPhone. (1/464th of a second) I don't know if the Droid X supports shooting at 80 ISO speed or not. If it doesn't, then it's not entirely unfair to compare the iPhone's 80 ISO speed against the X's 100 because they'd be both operating at the best quality (lowest ISO) they're capable of.
3rd photo comparison, which I found on Google: iPhone 4 vs. Droid X: A Head-to-Head Comparison - PCWorld
Again, I saved the first comparison images (full size) and checked out the Exif data, which is intact. The dimensions are nearly identical (1200X900 on X, 1200X896 on iPhone) and here, we have another ISO discrepancy, though a rather small one. The ISO speed on the X is 105, while the ISO speed on the iPhone is 100. Both were exposure times of 1/120th of a second. This tells us the iPhone was given an advantage here; no way to know if it was intentional by the PC World reviewer(s) or not, though. Either way, since the iPhone wasn't running at ISO 80, they both should have been at 100 to be fair. Definitely suspicious.
4th photo comparison, also found on Google: iPhone 4 vs. Motorola DROID X – 5MP vs 8MP camera photo samples
Again, I saved the first comparison images at full size and took a look at the Exif data. Dimensions are 639X480 on the X and 641X479 on the iPhone. Here, things are rather suspicious. The Exif data has been stripped from the Droid X photo, but it remains intact on the iPhone photo. The iPhone photo has an exposure time of 1/2742nd of a second which suggests VERY bright lighting conditions, and it has an ISO speed of 80. Talk about a worthless comparison; when you can't verify if testing conditions were fair or bias, it's not much of a test. I'm not outright accusing Daily Mobile of Apple bias, but I'm definitely accusing them of shoddy-at-best "testing practices". Oh, did I forget to mention that the Droid X pic size is 101KB and the iPhone's is 321KB? Whoops. They're both JPEG images and the file sizes should be very similar; less than a 10% discrepancy, since their pixel dimensions are virtually identical. Yet we have a discrepancy of a little more than 300% here. This is more biased than 1939 radio broadcasts in Germany. Shame on you, Daily Mobile.
Next up, our final contender, also found on Google: iPhone 4 5MP Cam v. Droid X 8MP – A Comparison | ProgrammerFish
Well, I really WANTED to look at the Exif data, but once again it has been stripped on both images. The X's dimensions are 640X478 and the iPhone's are 640X360. Different aspect ratios. The file sizes vary somewhat because of the different aspect ratios, the X is 121KB and the iPhone's is 67.6KB. This seems like too large of a discrepancy, the iPhone's size is 56% of the X's, yet it's only got about 1/3rd fewer pixels. It should be somewhere around 80KB in size. It's possible this review is biased and in favor of the Droid X; or it could be ignorance on the part of the reviewer. I'm leaning towards the former.
For the camera geeks here, the Droid X camera uses an f-stop of 2.8 and the iPhone 4's camera uses an f-stop of 2.5. (assuming the photos that have Exif data are correct) For the laymen, this means the iPhone is a 3rd of a stop down from the Droid X. The iPhone camera lens lets in less light; which means that, if all other settings are the exactly the same, it should take a slightly lower-quality photo. This also means that the Droid X requires more time to take a photo, which theoretically translates to the iPhone *POSSIBLY* having better photos of things in motion or better photos in low light. There are many other factors that go into this, and I'm not claiming that the iPhone has the aforementioned advantages. Can anyone confirm that the Droid X cannot go below 100 ISO speed? It doesn't say in the manual.
The entire point of this long post is that I haven't seen a fair photo comparison yet. (at least, not one that I can 'prove' is fair) I'd like to see one if anyone sees this that has their hands on a Droid X and an iPhone 4; or if someone finds another review on the internet that looks fair. Particularly at higher ISO speeds like 200 and 400, which one would need for moving objects that aren't moving slowly, sporting events or low-light conditions.