When apple introduced the orignal iphone the camera hardware was obviously not a high priority. That has changed. The photographic capabilities of the iphone have actually proved to be much more important than Apple originally envisaged and with every new iteration of the phone they’ve increased the performance of the camera. Or rather they have increased the specifications of the camera.
Last Friday I attended a talk by David Graham at the Apple store Regent St in London. I’d previously met David when he introduced himself to me at my own talk at the Covent Garden Apple store in London. On Friday though he posed me an interesting question. Did I have a new 4s and did I think the focus on it was worse than the previous iPhone4. Well, the answer to the first question was yes, I did have a new 4s but I had never noticed or considered whether it was worse at focusing than the previous version. This could of course be due to me not really having used it in anger. I’ve been rather busy of late with personal stuff and preparing the London iPhoneography groups presentation that we did last Saturday at Regent St Apple store. David showed me one of his images onhis phone and zoomed in on it. He seemed sure it was softer than expected. We decided that some testing should be done. So here it is.
Be warned, this is not some super geeky techno test like you’d get in a camera mag. No, this is my own simple test done in my office/dining room and back garden. The plan was simple really. I set up a 750watt constant source softbox light pointing at a creamy white paper background hung from my curtain rail. I then put my 4 and 4s in to the same Owle tripod mount on a manfrotto carbon tripod. Using myself as the model I took a series of portraits, or actually my beautiful assistant /wife, took the portraits of me. She was instructed to stick her finger on the point at top of my nose between my eyes so the little blue box would appear and focus there. Then she could press shutter release.
Some notes: The focal length of the lens in the two phones is different. The 4s has a wider angle of view so that is why I appear smaller in one shot than other. The tripod wasn’t moved. I tried moving it on the outside shots coming up though.
Iphone 4 f2.8, iso125, 1/100th
Iphone 4s f2.4 iso100, 1/100th
There is an obvious difference in colour here. It’s not just white balance though. Both seem to have white balance wrong…the white background is creamy coloured yet the shadow area in 4 seems a little greenish while in 4s it’s more purple/blueish. Then there is the significant difference in skin tone.
Lets look closer
These are crops of the previous shots and remember there is no post processing on this. These were just cropped in photoshop and saved at maximum quality.
Ignore the colour difference. Just look at the background on the 4 shot. You can see compression noise all over it that is just not present in the 4s shot. On first inspection the 4 shot looks like it has more detail though. Look at my forehead and cheek. Look again though, it’s not detail, it’s noise. It has the same pattern as the noise in the background. The 4s has the actual detail and no noise.
In my day job I distribute hi-end video processors. They are used to increase the image quality and accuracy of fixed pixel displays (lcd/plasma/ tv’s and projectors). Primarily they go in to domestic systems where they upscale standard def content to HD and do sharpening, noise reductions and colour conversions. So I have, for the last 10 yrs had a decent amount of experience with digital broacast technologies. I am giving you this background info so you can see I have some knowledge behind my reasoning.
Looking at the technical specs of each shot we can see the 4 has a higher ISO rating. This is because to get the correct exposure with a smaller aperture (f2.8 v f2.4) it needs to amplify the light more. Higher iso’s generally mean more noise. This could be one of the reasons that there is more noise in the 4 shot. Now of course it could well be that the 4s is actually applying some form of noise reduction system when it’s creating the jpg internally. Noise reduction, no matter how good it is, will likely as not remove detail as well as noise. This can give an unnaturally smooth effect. If you have a tv with noise reduction go to the news channel and turn it on and watch all the detail in peoples faces disappear as they start to look like they are made of clay. From looking at these crops it would seem to me that even if the 4s does have noise reduction applied it’s not overdone as there still seems to be plenty of detail available. ( I am pretty sure there is noise reduction going on).
Now when we are talking about sharpness it gets kind of difficult to compare here. Lower resolution images often look sharper to us than high resolution images. Compression aretefacts that appear at areas of high contrast can have a weird sort of artifical sharpening effect and we can see from the crops that noise can appear to look like detail at times. From looking at the unprocessed cropped shots it would seem to me like the focus is fine in the new 4s and of no difference to the 4. So, those were done inside in artifical light. I thought it worth stepping out in the garden this afternoon to take a shot of one of my apple trees. Again, unprocessed but this time I moved the tripod closer to the tree for the 4s shot to try and get the same composition within the frame .
Iphone4 f2.8, iso80, 1/450th
Iphone 4s f2.4, iso64, 1/557th
I’m not going to bother with crops on this. If you look at the shrub bottom left of the tree it is obviously slightly blown out on detail compared to the new 4s. The dynamic range capability of the 4s seems greater and it shows here. The grass and tree stump all look much more textured and detailed to me on the 4s. The point of focus on these was the base of the tree stump. That is where the phones were told to focus and expose for.
So my not overly technical critique would be that the camera in the 4s is less noisy, more detailed and with a wider dynamic range of the previous iphone 4. I also don’t see any focus issues with my own. I’ll end by saying that the truth of it all is not in the actual hardware anyway, its in what you do with the hardware to create the image/art you want. So I’ll end with two post processed versions of the first two shots of me. I’ve tried to get the skin tones as close to each other as I can with these. They were processed in snapseed, iris and filterstorm. I think I went too far on the processing in the 4 one compared to the 4s…although I can imagine some folk would like hte extra gritty look to the 4 one….
I’m sorry about the quality of the model but it’s the best I could do at short notice!