dirt in sky but not on paper


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Jul 19, 2007
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#1
ive recently seen some dirt on my pics where the dirt is on the sky. however, ive tried taking a pic of a piece of white paper under indoor lighting and there seems to be no dirt. also, all other pictures (indoors) seem to have no dirt on them

could this be due to the fact that the lighting is stronger outdoors and thus the dirt appears? ive also taken a look at my sensor (its a d70s) indoors and found no dirt. tried this on 2 lenses already

can any1 explain this and advice wat i shld do:dunno:

below r pics taken with same lens (50 f/1.8) - similar results with my 12-24

large(r) pic here: http://farm3.static.flickr.com/2370/2220493110_0dbc58a744_o.jpg
and

large pic: http://farm3.static.flickr.com/2015/2220486784_0093e3d204_b.jpg

thanks in advance:D
 

behyx

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#2
Are both of them taken at the same aperture? (preferably as small as possible.. try f22)

Possibility might be dust on your lenses. Clean the lens and try? :)
 

Jul 19, 2007
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#3
oh yeah! forgot abt the aperture thingy
took pics of both the piece of paper and the sky at f/2.8 and f/22 and theres a lot of diff
the paper now shows dirt:


but still id like to noe if brightness plays a part too cos i took 2 shots, both at f/5.6 of a 1/2 indoors scene and the sky and the dirt appears only on the sky

and btw i sent it for cleaning in Nov last yr, so its still under warranty. does tt mean i can send it back for cleaning for free?

thanks for ur help so far:)
 

night86mare

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#5
you have to set it to manual, and force the smallest aperture possible, exposure about +1.0 based on in-cam metering usually to see. also use manual focusing and make sure the paper/sky is oof, easier to see.

aperture settings have to do with dof, at f/5.6 dof is shallow hence you will not be able to see the dust right in front of your sensor because it is honestly very oof already

at f/13 and above, (usually f/22 is pretty clear) dof is deep (or maximal) hence you will be able to see the dust.
 

Jul 19, 2007
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#6
thanks for the quick replies!:)

ok, so i guess it was prob due to the aperture not being small enough

the receipt says '3 months warranty for workmanship only, excludes lens cleaning for fungus and further replacement of parts if necessary' does tt mean free servicing if i send it within 3 mths?

and also, for self cleaning, has any1 tried stuff like products from visibledust using dry cleaning with a brush?
 

night86mare

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#7
do a search for cleaning

there are many many threads here on this, you should have already seen at least 10 since jul when you registered :bsmilie:
 

varf

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is it dust on the sensor or lens?

repeat the same white paper test at small apertures with both lenses. if you see similar patterns of dust marks, it is your sensor that is dirty..
 

Jul 19, 2007
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#9
do a search for cleaning

there are many many threads here on this, you should have already seen at least 10 since jul when you registered :bsmilie:
yeah i suppose so. but they mainly suggested wet cleaning, and im wondering if this product actually works and if any1 uses it

is it dust on the sensor or lens?

repeat the same white paper test at small apertures with both lenses. if you see similar patterns of dust marks, it is your sensor that is dirty..
its the sensor. i did the tests and now i can see the dirt, cos previously i used a larger aperture on the paper test, and a smaller aperture on the sky
 

night86mare

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yeah i suppose so. but they mainly suggested wet cleaning, and im wondering if this product actually works and if any1 uses it
arctic butterfly works, i have used it before, and it helps somewhat

but if you want a thoroughly clean sensor then you would need a combination of BOTH wet and dry cleaning. the humidity in singapore dictates that you would more likely than not encounter welded dust (dust with moisture).. which dry cleaning with an arctic butterfly would not solve.
 

Jul 19, 2007
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#11
thanks for the quick replies;)

ive already gotten wat i need, and besides im getting info abt the artic butterfly on another dedicated thread

i'll leave this thread open, though, in case any1 wants to share smth;p
 

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