Marks on photos

[botty1963]

Hi folks, I'm having some issues with marks on some of my photos. I know it's the body and not the lens as it does it regardless of lens, but the marks don't appear on all photos. They are consistently on the same short edge of the frame, so top edge in portrait and right hand edge in landscape.

I have cleaned my sensor, and inspecting it I can't see any marks at all but still they appear on some of my photos. If you look at this photo you can see them a the top. Any suggestions would be appreciated.

[Dave Humphries]

Hi Steve,

These are almost certainly smears on the sensor surface, they must just look see-through when viewed by eye.

The reason they only appear on some shots, not all depends on two things; primarily the aperture used, the narrower (e.g. f/11 - f/22) the more likely you are to see them, the other factor is what is in the image; for example, if you'd shot this one with the camera 'the other way up', you wouldn't have seen them.

Given the fact you've already had one attempt at a clean (and this must be the result) and from the shape of the blobs, we can skip advising you try other remedies first, you'll just have to wet clean it again (either yourself or have it done for you).

HTH, Dave

[Inkanyezi]

It certainly looks as dirt on the AA filter, and if you look at the sensor, it sits near the right edge. They are more visible when the diaphragm is small than shooting wide open. Often dirt specks are not seen at all when the lens is wide open, but are more prominent in very bright light and the lens is stopped down.

[John 2]

Just a thought - are you looking at both edges of your sensor because the I think the image on the sensor is upside down and flipped left to right, not as you see it in VF.

[DanK]

I agree with Dave--almost certainly dirt on the sensor (that is, on the AA filter in front of it). The fact that they are not round suggests smears rather than dust bunnies.

The exif is stripped from your photo, but I am guessing that you shot this at a fairly narrow aperture. Is that right? that will make sensor dirt more visible.

I always clean my own, but I have always had dust bunnies and never smears. The question is what is smearing. If you accidentally got some oil on the swab by going past the edge of the sensor, that might cause it. It may be harder to clean than dust is.

I think my next step would be to see if I can see the dirt. The position will be reversed, as John pointed out. There are loupes designed for this, but a bright flashlight (I guess you would call it a torch) a magnifying glass is usually enough. Then I would try cleaning that area, working from center to edge. If that doesn't do it, given that you are new to this, it might make sense to let a shop do it.

[Inkanyezi]

Read instructions on sensor cleaning and follow them meticulously. It is important that the swab is passed only once, in order not to move dirt around.

[dem]

Just a thought - are you looking at both edges of your sensor because the I think the image on the sensor is upside down and flipped left to right, not as you see it in VF.

Quite right. We also do not know how the camera was held during the capture. I have noticed that on all my tripods the camera has to be turned clockwise to achieve portrait orientation (with the shutter button ending up below the VF). If I shoot handheld, it is always the other way round. Just an observation.

[Black Pearl]

Quite right. We also do not know how the camera was held during the capture. I have noticed that on all my tripods the camera has to be turned clockwise to achieve portrait orientation (with the shutter button ending up below the VF). If I shoot handheld, it is always the other way round. Just an observation.

Really?
I can't recall ever having that happen on any of the tripod heads I've owned., and there's been a good few over the years.

[jcuknz]

It is also a factor if you are right eyed or left as I always hold the camera with trigger below lens as a left eyed person but I see in instruction books the opposite for REPs ... a most peculiar way to hold a camera IMO

[botty1963]

I was gutted yesterday when I again noticed similar marks on the photos, I had given the sensor a clean and the glass on all of my lenses. Yet again, on some photos but not others....aaargh

[NorthernFocus]

Have you had this problem since day one or is it recent phenomenon. What camera?

[xpatUSA]

I was gutted yesterday when I again noticed similar marks on the photos, I had given the sensor a clean and the glass on all of my lenses. Yet again, on some photos but not others....aaargh

For your amusement, have a look at my recent post here:

http://www.dpreview.com/forums/post/57403087

I found the best way to eliminate the lens from the investigation is to remove the lens and the dustcover, then shoot something white.

Possible on Sigma DSLRs, don't know about others.

P.S. this morning I shot breakfast which was on a large white plate . . y'all know the rest.

Now I have to buy a proper kit and do a proper job

[Dave Humphries]

I was gutted yesterday when I again noticed similar marks on the photos, I had given the sensor a clean and the glass on all of my lenses. Yet again, on some photos but not others....aaargh

Hi Steve,

Are you sure you had actually removed the problem with the first clean?
e.g. did you retest using my guidelines for seeing it best as stated in post #2 above?

If so - and it has 'returned'; the next most obvious issue might be your lens changing technique - i.e. could you somehow be letting crud get in when swapping lenses?

That said, some cameras have been known to 'throw' oil on to the sensor.

As Dan has asked; what camera do you have the problem with?

[DanK]

I was gutted yesterday when I again noticed similar marks on the photos, I had given the sensor a clean and the glass on all of my lenses. Yet again, on some photos but not others....aaargh

Sensor dirt usually doesn't show up on all photos. It is most likely to be apparent in images with plain surfaces taken at narrow apertures.

The first question I would ask is whether the spots still show up in the same location. If they don't, then you probably just moved the dirt around when you tried to clean it. If they do, then either you failed to clean the sensor, or there is something other than simple dust there. As I wrote last time, the fact that blemishes are long and thin suggests smears rather than dust bunnies. If that is so, then cleaning it your self may be tough. For example, if it is oil, the normal procedures may not be enough.

I suggest you take a photo of a plain surface--a white wall would be fine, a featureless sky would be fine--at f/22 and post it.