Clean Sensor: How important is it?

[AB26]

This is not something you would normally do: leaving streaks on a sensor after a “wet” clean. It happened to me and yesterday I did a proper clean, getting rid of all the streaks and other dirt. Afterwards I was thinking about the influence of a dirty sensor.

I came to the conclusion that a dirty sensor will influence exposure, colour rendition, saturation, focus and probably anything having to do with the quality of the captured image.

I am not sure if I came to the wrong conclusion or not, and I would like to hear from you people what your experience is.

How important is it to keep the sensor of your camera perfectly clean?

[Shadowman]

The first sign that something is dirty is when you see these odd streaks in your images. At first you assume it was a bird streaking by and so you edit it out of the image. Then when you start seeing the same streak or dot appearing in all your images you know that at first 1) it's a nuisance, 2) begins to greatly affect all your images, 3) becomes a pyschological obsession trying to locate and correct. So I would say over time it becomes more and more important.

[Glenn NK]

My take on it is that clean is good, but perfectly clean is impossible, so attempts at perfectly clean would require that one does nothing but clean sensors all day (and even that won't achieve perfection).

I think what's important (significant) is that the sensor is clean enough that the affect won't show up on the image, but this varies with the apertures being used.

When I'm doing flower closeups, f/4 would be a typical f/stop, and not much is going to show up at that setting. For landscapes where f/16 might be used, cleanliness is more important.

Obsessions are destructive.

Glenn

[Inkanyezi]

Mostly "dirt on the sensor" will go unnoticed. The reason is that it isn't actually the sensor, unless yours is without an anti-aliasing filter.

There's a fairly large distance between the sensor and the filter, on which the dirt sits, and that's one of the reasons why dirt usually will not be noticed in images. When the aperture is large, light will pass around the dirt spot, making it less conspicuous. The other reason why we mostly don't see it is that image content is often such, that dirt on the sensor is drenched in details in the picture.

You will however notice any dirt, if you shoot something bright that has very little detail with a very small aperture. The shadows cast by dirt will make dark spots; hence it will bee most noticeable in fairly bright areas with even tone and little detail, like the sky. This is also the way we can analyse any dirt that might become visible in our pictures. By shooting an evenly lit surface at a very small aperture, or even by shooting unfocused, as the inside of a semi-transparent lens cap that is used for colour balancing, also at a small aperture, we can see all dirt spots that could affect images.

How important to keep perfectly clean? The question is akin to the one about the length of a piece of string.

[tclune]

Well, I only clean my sensor when I notice smudges in images, so it's important by the time that I clean it. Folks who are more fastidious may have a different answer, or maybe just the same answer but with higher standards...

[drjuice]

I'm still kinda mystified by this question. I found after having had four 35mmSLRs, half a dozen PnS, and now my alpha700. that one of the best things about the alpha700 is: the built-in shaker that causes "stuff" on the interior surfaces to be joggled into the little tray at the bottom. Any specks of dirt, even teeny ones fall with my "shaker". If the area is dusty/windy/foggy, I change lenses only in my car. Now, immediately below with the pieces and parts identified in the image, I'll describe how I keep things pretty well clean.



And as a regular thing, I am very careful when changing lenses, especially in the field. I have a spare lens cap for each side of all my lenses, a spare cap to cover the back of the lens mount, and another cap to cover the camera's mount. This way, if it's necessary, I can cover on all the separate pieces. Additionally, if I absolutely have to change lenses in a not-clean environment, I hang the camera around my neck so that for the back of the camera is towards up towards my chin and the camera body mount is hanging down towards my toes. The new lens is out of its container and with the lens front "face down" down on a flat surface. Then, being extremely careful, I remove the "old lens" from the camera body lens mount and place the old lens on the flat surface with its mount down on the flat surface.

Next, I pick up the "new lens" taking care to match the orange dots (both the lens and the camera body have orange dots to facilitate matching the two) and put the lens into the camera body mount and twist the lens into the body mount.

Then, I check to be certain that the lens is properly seated in the camera body mount, because it's always possible to mess up. Now, the camera is ready to go.

Finally, I put the cap over the "old lens mount", again being certain that the cap is properly seated and firmly in place.

Since I started following this procedure, I've not had to send my camera out for official cleaning and I haven't had ANY instances where blobs show up on my images.

Hope this helps.

virginia

[William W]

How important is it to keep the sensor of your camera perfectly clean?

Depends on the image.

Using a Large Aperture and a mostly Dark or Busy image - usually not all that important:


Even a mainly High Key image, if a Large Aperture is used and the major proportion of the frame is OoF and the Subject is Busy - then probably won't matter too much either:


Shoot at a Medium Aperture, or smaller (in this case F/9) and include a reasonable area of in focus and smooth subjec (in this case clear sky) - and the muck is quite apparent:


And the crop:


***

If you want to see how much garbage you have collected, then make an image of the clear blue sky at F/22.

WW

Notes: These are a set of reasonably consecutive images made with the same camera and no cleaning in between the shots. The images are essentially the JPEGS’s, SOOC and only cropped and resized for web presentation

[DanK]

I've never had streaks appear on their own, during normal use. I can see how streaks could arise when cleaning, but I have been lucky so far and have never had them. All I have ever experienced is dust bunnies, which as far as I can tell do no harm other than creating blurry spots at small apertures. I don't think they have any effect on anything else. So I clean the sensor when I see dust bunnies in my images and ignore the image the rest of the time. Between being careful changing lenses and having the Canon self cleaning every time I turn the camera on and off, I don't have to clean the sensor very often.

[ktuli]

There doesn't seem to be much that folks have missed, but I'll throw this out there just the same...

Generally, following good practices, your camera should stay clean enough that sensor cleaning should be a fairly rare thing. I used my camera for years before noticing any spots - and even then it wasn't till I got the MP-E65mm and was doing super macro work at magnifications higher than 1:1 and very small apertures.

After my first cleaning, I noticed that I left a couple spots. I ignored them for a while, then a few months later did another cleaning to try again. The second cleaning left only one spot remaining and it is incredibly tiny and easily ignored in 99.99% of my photos.

Now, if you are not satisfied with your current sensor cleaning job, I would recommend doing another one until you are satisfied, but beyond that I would limit the number of cleanings as much as possible. If you are consistently getting unsatisfactory results when you clean the sensor yourself, I recommend researching what you might be doing wrong or getting a professional cleaning done (perhaps ask if they can show you how to do it so you can correct your mistakes).

In general, if your sensor spots are few in number and small, I would recommend using the tools in Photoshop (spot heal, content-aware fill) to correct them on only the absolute necessary images. Most times, sharing photos on the web are compressed anyway and the majority of spots will not be noticed, but if you're sharing something fullsize or are printing, then take the time and cleanup the spots.

Just my $0.02.

- Bill

[AB26]

Hi All,

Thank you for the replies. On the NET I cannot find anything referring to the influence a dirty sensor might have on camera functionality.

If there is dirt on the sensor and it blocks the amount of light the camera systems anticipate to be entering the photo sites will it influence camera functionality? Those little spots you see on a dirty sensor could be covering hundreds of photo sites. Has anyone ever noticed any improvement in image quality after cleaning the sensor of a camera?
I have read articles where pro's recon the vibrating sensor cleaning system is only a sales gimmick.

Do you think a dirty sensor could cause incorrect exposure?

[Shadowman]

Hi All,

Thank you for the replies. On the NET I cannot find anything referring to the influence a dirty sensor might have on camera functionality.

If there is dirt on the sensor and it blocks the amount of light the camera systems anticipate to be entering the photo sites will it influence camera functionality? Those little spots you see on a dirty sensor could be covering hundreds of photo sites. Has anyone ever noticed any improvement in image quality after cleaning the sensor of a camera?
I have read articles where pro's recon the vibrating sensor cleaning system is only a sales gimmick.

Do you think a dirty sensor could cause incorrect exposure?

You'd have to have a uniform film across the lens to affect exposure, however if you are using spot metering and the spec just happens to be spot on....

[GrahamH]

I've been playing around with the Nik software (as many of have I am sure) and I've noticed that the more extreme I go, the more visible the dirt - and for me there is a LOT of it.
I frequently change lenses depending on my requirements and even using best practices (given the particular situation I am in), it's easy to get some dirt in. Lots of beach and dust everywhere on the island and it's usually not possible to change lens in a clean environment. (Leave some water in a basin for a couple of days and check out the dirt ring that forms).
For example doing landscapes while knee deep in the sea 100yds offshore and I want to change from 18mm to 500mm cos of some bird. Or any significant change of composition requiring a change of perspective - which happens all too frequently. I'd rather get the shot and some dirt than not the shot at all.
I end up spending time cleaning the image when I would rather be dealing with the image itself (or out shooting, or anything else more interesting).
FYI I clean my sensor myself - IPA and a cotton bud, a steady delicate hand and some patience. Can't buy a sensor cleaning kit on island (but they will charge you for the cleaning themselves - can anyone spell cash cow).
In summary - clean sensor - very important, but easy to do yourself.

Graham

[AB26]

You'd have to have a uniform film across the lens

Hi John,

Do you mean lens or sensor filter?

I have to assume you mean sensor filter as a spot on the front of a lens will have little to no effect.

Yes I am talking about a fairly uniform "film" across the sensor.
As stupid as it may seem I have actually had it on my camera.

I think the same thing might happened when you dry "swab" an oily sensor.

[AB26]

In summary - clean sensor - very important, but easy to do yourself.

Not according to KR, yes that KR. He recons it is a no no to touch a sensor.
I am of the opinion if you have ever cleaned your own cars windscreen you can clean your own camera sensor.
However it is not an operation that should be attempted by any person with Alzheimer's.

[Colin Southern]

If there is dirt on the sensor and it blocks the amount of light the camera systems anticipate to be entering the photo sites will it influence camera functionality? Those little spots you see on a dirty sensor could be covering hundreds of photo sites. Has anyone ever noticed any improvement in image quality after cleaning the sensor of a camera?

Assuming that we're talking about a normal DSLR camera then the answer is NO. The amount of light that is attenuated by dust on the sensor pales into insignificance compared to the amount of light attenuated by the shutter which is normally closed during exposure metering.

I have read articles where pro's recon the vibrating sensor cleaning system is only a sales gimmick.

I've read articles where it was said that the North Korean leader was voted sexiest man alive; just because we read things on the internet (even if said by a "pro") still doesn't mean it's right. The vibrating sensor technology is part of the dust spot elimination system; bottom line is it helps, but it'll never remove all dust (especially what are deemed to be "welded particles").

Do you think a dirty sensor could cause incorrect exposure?

No.

[Colin Southern]

Not according to KR, yes that KR. He recons it is a no no to touch a sensor.

KR is somewhat of a colourful character. I like him, but the bottom line is that he's colourful and controversial and authoritive sounding to get traffic to his site -- so he can pay his bills. From KR's very own about page ...

This website is my way of giving back to our community. It is a work of fiction, entirely the product of my own imagination. This website is my personal opinion. To use words of Ansel Adams on page 193 of his autobiography, this site is my "aggressive personal opinion," and not a "logical presentation of fact."

[Inkanyezi]

I had dirt on the sensor of my Lumix G1, dust spots that did not come loose with the ultrasonic shaker. I put reading glasses on and removed that dust with a cotton tip, dry, no liquid. It worked well. The AA filter is a soft plastic thing. When doing the operation, I saw it budge from the very light pressure of the cotton tip, but it sprung back just as readily, and the dust was gone, leaving no scratch.

I don't recommend to do it, but I did it twice, and it did no harm to the sensor (AA filter). As the Lumix G1 is a mirror-free camera, the AA filter is easier to access than on DSLR, so it might also get dusty at a higher rate, as the shutter is wide open when the lens is removed. On the OM-D I still haven't needed to remove any dust.

The trickiest part with the cotton tip was to find out where the dust spots sat. They are tiny, very small, and not easy to find just looking for them directly. A mirrored image upside down where they appear helps a lot in localising them.

[AB26]

The AA filter is a soft plastic thing.

I am surprised at that.

This is an extract from: http://www.bythom.com/cleaning.htm

First, don’t be put off by Nikon’s disclaimers (both Fujifilm and Kodak endorsed user cleaning that touches the sensor if done properly). The Lithium Niobate filter over the Nikon sensors is somewhat difficult to scratch if you use the right tools (on the MHOS Scale of Hardness table that ranges from talc at 0 to diamond at 10, Lithium Niobate is a 5, the same as Apatite, and a bit lower than Orthoclase and Quartz; Fujifilm and Kodak don't identify the material they use [nor does Nikon on the latest cameras], but it seems just as durable). While it's possible to scratch the filter surface, it's also not at all easy to do if you're using the right tools.

Thanks Urban.

[AB26]

Thank you People,

After all of the above I am back to the drawing board finding a resolution as to what I have experienced after doing a proper sensor clean.
Although I only did a sensor clean, without adjusting any function on my camera, I am sure there is a significant improvement in colour rendition and saturation.

[Colin Southern]

The AA filter is a soft plastic thing.

It may be on a Lumix G1, but it certainly isn't on most DSLRs; it's far more robust than most people think.