Camera Nitty Gritty - part 1
In part 1 of a new series, Steve Litchfield looks at exposed camera glass on some phone models and investigates whether scratches really make a difference.
Part 2 will investigate the pros and cons of LED/dual-LED/Xenon flashes in camera phones, while Part 3 will investigate the fabled 'Megapixel myth' with an objective eye...
Moving up to the Nokia N95 8GB from the N95 'classic', I had one big worry, and only one - the unprotected camera 'glass'. As I used the phone day to day, I took to wiping it with a corner of my shirt before taking photos - after all, the glass does tend to collect dust and finger grease and this would be bad news for picture quality.
And rightly so. What I didn't realise was that the wiping process itself was grinding microscopic particles of dirt against the glass (I should have used a clean tissue or dedicated lens cloth) - it looked clean to the naked eye but, when viewed from a certain angle so that the surface caught the light, you could see a grid of tiny scratches - all rather ugly and shocking. This is the result of 6 months intensive and careful use:
Ugh. Now, the big question, of course, is how does this affect photo quality? I'd expected, naturally enough, that my photos would be more blurry and less detailed than those that would have been taken if the external glass was still in pristine condition. But I ended up being rather surprised - pleasantly.
For this, part 1 in a camera-themed series of All About Symbian articles, I took a pristine N95 classic and the aforementioned 'scarred' N95 8GB, both upgraded to latest v30 firmware. By taking the same photos under identical controlled conditions, I hoped to demonstrate the difference the external scarring made. Here's the first shot, taken in good natural light, indoors:
And here are extreme blow-ups, with the N95 on the left and N95 8GB on the right:
As you can see, the detail is almost identical. Maybe, just maybe, there are better colours and detail in the N95 version... but I'd hate to bet my life on the difference. The N95 8GB version seems more 'noise-smoothed' - I'd hoped that the algorithms in the two devices would be identical, seeing as they had the same firmware, but it seems that some of the image processing happens in the camera's own electronics and is perhaps fixed.
How is this possible? How can the camera on the scarred-glass N95 8GB perform as well as that on the pristine N95 classic? The answer, in normal, diffuse lighting conditions (as above) is that light from each point in your subject arrives the sensor via multiple paths, as shown in the diagram on the right.
So the effect of even 50 small scratches is minimal, with plenty of clear surface area for enough light to get through to register successfully on the sensor. Yes, there's probably a tiny amount of light scattering going on around each scratch, but the effect seems to be negligible.
Now, the brighter and more focussed the light source, the more vicious the scattering effect at each scratch and (potentially) the more detrimental it will be to the final photo. With this in mind, I switched to a pure-flash shot of the same subject. Here's the full image:
And here's the extreme detail comparison:
As you can see, the results are similar to the non-flash photo. The N95 classic version shows slightly more light and colour and definitely more digital noise, while the N95 8GB with its extra 'blurring' algorithm deals with the noise but can't quite match the intensity of the original's image.
The other effect I'd been expecting was flare and light artefacts resulting from the flash interacting with the scratches. In an attempt to drive this effect, I tried shooting a photo, with flash, into a mirror. This is, you'd think, just about as bad as conditions might get for a camera with scratches on its cover glass. Here's the same comparison, N95 classic on the left.
Now we're getting somewhere. Part of the difference is down to the N95 8GB's extra noise reduction algorithms, but I'd argue that there's slightly more flare, and slightly more general haziness and loss of detail generally.
What about taking things to the natural extreme and shooting a subject into the sun? This is something most people try for effect at some point or other - the subject often ends up looking like a silhouette if you're not careful, so it's more an arty than a sensible thing. But it's a good test of the light-scattering effects of a scarred camera glass, so... Here's the result, again with the N95 classic first and then the N95 8GB image below it (both resampled to fit here):
There's a definite extra couple of big sun 'flares' in the N95 8GB image, which I'd put down to interference effects from the grid of scratches on the cover glass, although without knowing the details of Nokia's noise reduction algorithms I can't of course be 100% certain. But extra flare is the right sort of side effects for scratches.
Mind you, as someone going for an 'arty' into-the-sun shot, the extra flares arguably make the photo better and not worse. Arguably. The purist would point out that the shot from the pristine lens was more accurate in terms of representing what the human eye sees. Your call.
I've been dealing here in extreme blow-ups and extreme lighting conditions. The bottom line from this, part 1 in the series, is that for 99.9% of 'normal' photos, you simply won't notice any difference whatsoever between photos taken when your phone is new and those taken when it's lived in your pocket for six months and has some battle scars on its (unprotected) camera glass.
I know that this topic has been much debated online, with Nokia somewhat ridiculed for a bad design decision for the N95 8GB and N96, but, despite my own prejudices, I'm going to side (just) with Nokia on this point. Yes, more protection is obviously better and I'd jump at a protected camera lens model every time, all other things being equal. But hopefully I've demonstrated that the effect on photo quality is, to all intents and purposes, for a phone that's not neglected too much, negligible.
See you in part 2 of this camera phone series!
Steve Litchfield, All About Symbian, 10/9/08
Published by Steve Litchfield at 6:25 UTC, September 10th 2008
Categories: How To, Comment
Platforms: General, S60 3rd Edition
Feature Discussion
but there is always a solution to that, buy a leather case, and wear them always..
i've had my N95 8gb with the original nokia leather case since i bought it, november 2007, and there has been no scratch at all on the lens..
again..i guess it just depends on the usage of the person as well..
What next? The mega pixel myth? The fact the most people view their photos on 1.3 mega pixel LCD screens but still get upset when there camera phones aren't 8 mega pixels!. Give me colour depth over pixel resolution any day of the week! I would rather Nokia gave us a 3 mega pixel phone with 3x optical zoom than a 5mp without.
There are about 5 or 6 of these myths that could do with your detective work Steve.
Cheers,
James @ Nokia Creative
Shots into the sun or where the sun is behind the subject will have increased flaring and that is quite a common circumstance! Bearing in mind that only the n82 has a reasonable flash one could argue that the majority of photos taken by the Nokia camera phones are taken outside! That would mean that alot of photos could be affected by flaring.
Put it another way - why do ALL cameras come with a lens cap / lens protection? If scratches only affected 0.01% of pictures then I doubt camera manufacturers would bother.
Having a lens cover is clearly (sorry for the pun) a better idea. It seems this article is more about justifying a particular design than actually comparing the benifits of different phone designs.
The point about having your phone in a case is all well and good but cameras have lens caps and are kept in camera bags.... There is a reason for this!
So I decided to remove the particles and voilá - no more bad pictures. The objective, being so tiny and deep in the phone, doesn't get dirty.
Scratches on the camera glass only really affect the picture when you're shooting INTO light. And, as your mum probably taught you, you should usually have the light behind you when taking photos, so as to light your subject optimally.
Having a lens cover is clearly (sorry for the pun) a better idea. It seems this article is more about justifying a particular design than actually comparing the benifits of different phone designs.[/quote]
I think Steve was trying to point out the lack of a lens cover may not confer as many disadvantages as people think rather than justifying the design.
I think a lot of it is about perception - i.e. people think its better to have a lens cover... and to be fair it probably is.. just not as much as people might think.
Personally I like lens cover not for any protective reason, but because of the way they can be made to start the camera application. This sort of physical switch interaction is easier than starting an application via the UI. e.g. same with key lock switches / sliders.
On the other hand lens covers can take up a lot of volume (e.g. Nokia N73) and will generally always make the phone thicker than it could be. There's a definite trade-off.
The story should be mandatory reading to anyone running or thinking of starting a phone blog.. getting a little sick of all the off the cuff, unsubstantiated comments on how this or that "does not make any sense" or "it would have been easy for [Nokia] to put in a better [insert your spec of choise, including huge batteries]".
In fact, a basic primer on marketing, product differentiation and industrial design (and its constraints) would be a good start before starting a blog. That OR simply thinking things through a bit more and not just trying to make as many posts as possible.
Sorry for the rant. :D
Btw, I did in fact enjoy the editoral, although it comes across as Steve(once again) advocating on Nokia's part agian.
That said most people using a cameraphone to take pictures are just casual photographers and just want to take photos as and when. Bearing in mind that the majority of decent snaps taken with a cameraphone will be from outside it is fair to say that a decent number of these pics will be taken into the light where scratches may well affect picture quality. When you pay a premium for a phone and the manufacturers push for higher mega pixels and quality glass a decent lens protection system is important. Scratches will also become more of a problem as pixel densities increase.
Camera phone are increasingly being marketed as camera replacements and in that end they should come with lens protection. The N82 is not overly thick and offers decent lens protection and a nice method of launching the camera function - a win, win situation. Of course there is always a compromise but in the end of the day quality glass needs quality protection - I don't really see how you can say that it doesn't?
I think editorial like this is counterproductive. I would hate to see more and more cameraphones being offered with no lens protection infact I would like to see more and more cameraphones with lens covers! It will help the average user take better photos.
There we go.
"The N82 is not overly thick"
You should see the number of people in various phone fora saying that N82 is too bulky. Yeah, I don't agree either, but Nokia has to listen to those folks too.
"I think editorial like this is counterproductive. "
I think de-mystifying misconceptions can never be, in the long run, counterproductive. AND Steve never said it makes no difference. People need to read the text, not between the lines. :)
I am planning to buy a Nokia N95-8GB and the lack of lens protector was one of my concerns. Now I am a bit relieved that the photo quality will not be severely effected even if the lens gets some scratches. But still a scratchy lens would look unpleasing esthetically.
Has anyone used a lens protector? I have ordered a martin fileds screen protector pack for N95-8GB which comes with a lens protector as well. I am not sure whether that would decrease the quality of the photographs.
Anyone having some experience with lens protectors?
1) Looking at the N95 8GB picture. The N82 and the N95 classic with their shutter seem to have their lens deeper inside the body. Effectively functioning as a sunhood. This will mean the lens and sensor are better shaded against incoming light and light on the edge of a photo will less likely cause lensflares.
2) Scratched lenses will reflect or diffuse incoming light instead of project it on the proper spot on sensor where it is supposed to be. Diffused light will definitely will cause hazing. Reflected light can cause unwanted sensor areas to get less light or even more. It can even be reflected against the (black) wall lenscasing and cause hazing by being difusely reflected on the sensor.
To get a good idea of what scratches do on a lens, take a photo through a fence with the camera close up, making the fence wires nearly invisible and [B]hazy[/B]. compare that to a shot without a fence in the way and you get a good idea of the issue. The effects are subtle. Scratches have distinct negative effect on the contrast and sharpness of the photo/lens.
Any company that proudly writes Carl Zeiss lens on its mobile should protect them with a lenscover. I would expect Carl Zeiss to turn himself in his grave about that!
@STEVE:
1) The Zeiss lens of your N95 8 GB is not damaged. The protective plastic cover. Replacing the cover or removing it will improve your image quality. You might also be able to remove the scratches. There are liquids to repair scratches on laserdisks and cd's. Another option is to use a metal polish like Brasso. It's grain should be fine enough and I have seen people use it to remove a (anti-reflective) lenscoating after they damaged it (actually blew it up) . Still how well it works, no clue and no I am not trying it out on my N95.
2) Buy a new camera protective cover. There are several internet shops selling them. I.e:
[url]http://www.telecomtelecom.nl/?p=5&id=9656&tid=1423[/url]
Never ordered at them. So don't complain if they are unreliable.
If that's all true, then scratches on the lens itself may have no practical effect on image quality as they would be so small that they would barely block any light at all. They'd also be so near the lens (actually on it!) that they couldn't possibly appear in the picture either.
Because camera manufacturers (and stores) are ninnies... Every pro photographer I know tosses the lens cap in the trash immediately. Who wants to miss a payday because you got a black frame by accident.
To protect them, you add on a "sacrifical lens." The same is done by the military for night vision devices. In cameras, you use a filter, like a UV-B or something pretty or completely innocuous. If scratched or chipped, or broken, toss it and buy another.
The problem with point and shoots and camera phones is that none of the protectors are worth a crap. That I have seen. They tend to be cheap plastic, and not attached well so I fear can induce additional distortion just from that. Oh, and poor attachment means dust can get under them, making cleaning just as hard as always. Now you need to clean the real lens again.
P.S. If scratches bug you, stop wiping lenses with your shirt. Use cleaning fluid, air, etc.
The convenience in starting the camera. Faster and less prone to accident. :P
A scratch is not an obstruction.
the problem is getting the dust off the lens. sharp blowing doesn't do the job well, resorting to clumsily wiping the lens with a cloth. my previous phone was the n80 with no lens cover, which you simply wiped clean with your finger prior to taking the shot.
that's my tuppence ha'penny...
I only hope a whole bunch of people dont take Steve's words as gospel, because the article heavily implies that not having a cover wont affect picture quality for the majority of cases, when in my experience this simply isn't true. Yes, there are proviso's in this artical, but the language used is heavily biased. Use of emotive and non scientific figures such as 99.9%, and bold-font phrases such as 'simply wont notice any difference', make the tone clear.
The best thing a prospective buyer of an n95 8g can do is talk to someone who has one, and see what they reckon. I have pointed several of my friends back to the classic simply because of my own dissapointing experience. I love the 8g for the screen, for the memory, for the battery, but if you are using the camera and aren't prepared to case it up like i do, then it gets scratched, and contrary to what this artical proposes, they certainly can affect the majority of 'normal' pictures, as they did in my case. Just go talk to an owner you know, there's enough of them out there!
More generally, the point has been raised that the lens covers do allow dust in and then make the lens hard to clean. That is a valid point but I do not feel the best solution is to remove the cover! But rather to make a cover that is more dust proof or allows easier cleaning.
I love having a camera phone and would only like to see them get better, I am not hung up about mega pixels but I do feel strongly about clean, clear, undamaged lenses and I think that some form of lens protection is a good thing. The lens protection on my n82 stops finger prints and scratches but not dust whereas no protection at all stops nothing.
Discuss whether the extra width is worth it, discuss whether the current lens protection systems are hard to clean dust traps but arguing that no lens protection is an ok thing seems wrong.
However, what I did notice was that the lens of my Sony video camera had a "stain" on it, which you could see under certain light conditions. While this has had no obvious effect on the picture/video quality, I did take it back to the shop where my wife bought it; the guy there said it would cost at least €100 just to get it looked at, and that he was not surprised that the mark on the lens did not have a negative effect on the image quality.
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