How do scratches affect camera performance?

[Rafe]

The advantages and disadvantages of lens covers on cameraphones is a hotly debated topic. Recent Nseries devices have seen a mix: N79, N95 8GB and N96 (no lens cover) versus N79, N85 and N95 classic (with lens cover). In the first in a series of article on camera issues Steve looks at the question of whether scratches on the camera's protective glass really make a difference.

Read on in the full article.

It is always better to have a phone with a protection lens cover..
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..

[Jaggz]

Nice one Steve. Thank goodness someone has finally proven that light scratching on these phone lenses makes hardly any difference.

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

Mmmm not really sure about your conclusion that 99.9% of normal shots will not be affected by scratched lenses.

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!

[csapdani]

Here's my story: I accidentally cracked the lens cover on my N95 8GB. Pictures taken by night, especiall with opposite light sources, were totally awful. Even in daylight, when the Sun was only a bit in front of me, the image got partially blurred.
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.

[slitchfield]

@unregistered: well, all I can say is that I've taken over 500 photos over the summer, outside and mainly in sunshine - with this 'scarred' N95 8GB - and I haven't noticed a single incidence of unwanted flare caused by the scratches.

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.

[Hih]

Very interesting reading indeed. Thanks Steve.

[Rafe]

Originally Posted by Unregistered

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.

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.

[viipottaja]

Fantastic story. This is the kind of stuff that makes me come back to AAS every day.

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.

[genXhippie]

For argument's sake, regardless of whether or not evidence of scratches shows up in photos, one still should have a shutter present just to avoid smudges and/or dust build-up imo. For the money one spends on these phones, why should we be bothered w/ the chore of checking the clarity of the lens before every use? Point being, Nokia regards of scratches or not, should include shutters(on all high end phones especially), and stop being cheap.

Btw, I did in fact enjoy the editoral, although it comes across as Steve(once again) advocating on Nokia's part agian.

Im a photographer by trade I agree that one should light you subject from behind...

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.

[viipottaja]

"and stop being cheap."

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.

[Super Chimp]

One thing this article fails to deal with is the issue that my N95 8GB suffers from, and I know other N95 8GBs have suffered from and that is the outer lens coating peeling off. This happened after a relatively short time with mine & has adversely affected the camera performance of the phone ever since by causing a mist effect across the phone. That's why I am very unhappy that such an expensive phone has no lens cover.

Excellent article!! Thanks Steve.
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?

[snoyt]

Some simple observations from a pure physics viewpoint:


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 hazy. 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:

http://www.telecomtelecom.nl/?p=5&id=9656&tid=1423

Never ordered at them. So don't complain if they are unreliable.