Help! What is this mark?

Lynton

Lynton

awkward customer
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Lynton (yes really!)
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Random pic where it has happened:

imageproblem.jpg


Problem area circled.

Only ever seems to happen (from what I can recall with the 18-55mm kit lens) and not in every picture, I take with it.

Always in the same place.

Makes me think dust in the lens - but then surely would be in every pic with that lens.
 
almost certainly muck on your sensor
shows best at high f-numbers
take a picture of a blank wall at max f
 
Dust on the sensor. Theres a good few in the sky as well.
 
Cheers - but as mentioned - doesn't appear with all lenses and when I do a sensor check for dust - not much there..........??

Have heard horror stories about cleaning sensors etc............. is it best to send away for a professional to do, or safe to do yourself?
 
Very safe to DIY, as long as you use the correct equipment - buy an arctic butterfly (thanks guys, it gets used every week!) and some good sensor swabs and fluid and do it carefully!

A wet clean should only be required if really dirty and after that a regular sweep with the arctic butterfly (or similar - there are other products available) will keep the majority of dust-bunnies at bay.
 
Lynton said:
Cheers - but as mentioned - doesn't appear with all lenses and when I do a sensor check for dust - not much there..........??

Have heard horror stories about cleaning sensors etc............. is it best to send away for a professional to do, or safe to do yourself?
Click to expand...

itll only really show up at apertures above f10 on light backgrounds..

perfectly safe, ive done it! :D
 
Lynton said:
Cheers - but as mentioned - doesn't appear with all lenses and when I do a sensor check for dust - not much there..........??

Have heard horror stories about cleaning sensors etc............. is it best to send away for a professional to do, or safe to do yourself?
Click to expand...

Dust bunnies show more when you use a small aperture which is why you don't always see them - exif shows f29 for this image.


typed tooooooo slow as above
 
eek!

dusty-1.jpg


Just did as suggested above by mmcp42. (my wall isn't really that colour, just had a quick play in photoshop to highlight all the dust!!!)

Right - an arctic butterfly it is then - if the man who spends half his time in the conditions he does recommends one, it's good enough for me!

Thanks guys for all your help, nad now off to hang my head in shame at the amount of C**p on my sensor!
 
Just to throw a spanner in the works, I hate the arctic butterfly ;) I managed to get OIL on my D3 sensor by I presume touching a part of the chamber on the way in...

I now use sensor swabs on cleaning fluid, my sensor is spotless in about 45 seconds. Large Rocket blower provides backup :)

Gary.
 
Same here :)

Don't worry, I think most of us have had a grotty sensor at one point or other. It is quite safe to do it yourself and if you take yourself off to the tutorials section you will find some cracking stuff on exactly how to do it. :)
 
Like everything else seems to be pro's and cons to all........

right off to have a good look at Warehouse express.........

as an aside can I ask how often you guys clean your sensors - is a "when they are dirty", or "Ritually the first of every month"

I know Arkady mentioned does his weekly, but I guess extreme conditions!!!
 
I check mine before each wedding and clean as necessary.

I think I've done mine three times this year :)
 
The reason it shows up with the kit lens maybe due to shooting at a larger f number. As dust will show up far better shooting with an aperture such as f6.3 e.t.c rather than wide open with a fast lens.
 
never cleand mine ever...but then i am not using mine as much as others and my D90 has a thingy that helps with that which i do if i remember to
 
thanks all for your replys, help and advice.

Tomorrow is D-day for the sensor then! Have my shopping list. (Brillo pads, bleach and wire wool! :lol: )

Just one additional question, I am sure the answer is obvious, but I am being a munchkin tonight.... why is it more obvious with a higher f no?

I am guessing, and just a guess here, wide open = faster shutter speed = less time for light to hit the dust / make it obvious?
 
Stolen from the web as I couldn't explain it very well...


It is well known fact (and it is a bit over dramatized) that digital SLR cameras are very sensitive to the dust particles found in the air. These particles can settle on the image sensor, and will show up on the images as dark spots when the image is taken with a small aperture (high F number). When the aperture is open, the dust is usually not a problem, since the distance between the sensor's surface and the dust is large enough to get the dust out of the focal plane. When the aperture is smaller (usually smaller than F16) the rays of light are parallel to each other, creating shadows to the dust particles. These shadows will show up as clearly on the images. At F22 or smaller apertures, the spots become really visible.
 
Liam said:
Stolen from the web as I couldn't explain it very well...


It is well known fact (and it is a bit over dramatized) that digital SLR cameras are very sensitive to the dust particles found in the air. These particles can settle on the image sensor, and will show up on the images as dark spots when the image is taken with a small aperture (high F number). When the aperture is open, the dust is usually not a problem, since the distance between the sensor's surface and the dust is large enough to get the dust out of the focal plane. When the aperture is smaller (usually smaller than F16) the rays of light are parallel to each other, creating shadows to the dust particles. These shadows will show up as clearly on the images. At F22 or smaller apertures, the spots become really visible.
Click to expand...

Off topic excuse me all.
Look! ...Hoppy and others who know what the heck I’m harping on about ... a description of dof using the word parallel! :woot: ;)

Back on topic.
Yes, basically they can be seen better if they are caught in the right light. Narrower rays silhouette them, rather than a mixture of wide and narrow that you'd get from a low f number, which would bathe them in light instead so that they can't be seen.
 
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