As the title says, I found a recurring smudge in my photos when I was editing this one. You can see the smudge in the middle of the photo.

At first I thought it was on the outside of the lens, so I cleaned it off. Still there.

I ran the “clean image sensor” program on the camera. Still there.

So I detached the lens from my camera body and when looking through it with the aperture wide open, I could see the particle that was causing the smudges.

I then took a photo of a white wall with the flash on at the widest aperture setting I could (f/36) which I will be posting at the bottom of this post body. There the middle smudge and a smaller smudge in the lower left can be seen.

Is there anything I can do to resolve this? I can see there are 3 screws at the camera side of the lens that I might be able to unscrew, but I have no idea what’s inside or how complex it would be to pick apart. It wouldn’t surprise me if I just introduced more dirt by opening it up.

The smudge is very visible at any aperture setting greater than about f/6.

I appreciate any feedback.

Photo of a white wall:

  • falkerie71@sh.itjust.works
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    1 year ago

    I don’t think I’m qualified to give you advice, but I personally wouldn’t risk disassembling lenses myself to clean them. There are certainly guides online, but lenses have complicated optics inside, and at worst you risk irreparable damage to it. If the spot is too big that it bothers you (which it seems so), you might want to seek professional help. For the time being, I think it’s best to ignore it, or fix it in post.

    • hanke@feddit.nuOP
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      1 year ago

      Thank you for your reply. I think I’ll check if there is any local photography shop or studio that would be able to fix it for me. Feels like a safer bet.

      • Eufalconimorph@discuss.tchncs.de
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        1 year ago

        Much safer. Ideally internal lens repairs should be done in a laminar flow cabinet (which produces a constant dust-free & fungal spore free wind to blow any contaminants out of the cabinet), but those are a few thousand dollars.

  • hanke@feddit.nuOP
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    1 year ago

    Yeah, you were all right. I just managed to get to my sensor for real this time and can see the spec of dust on there. Previously I think I was just looking at the mirror… Does it show that I’m a newbie? haha.

    Well, I tried to blow the dust spec away with a blower thingy, but that didn’t work. Considered using compressed air, but the internet said not to. So now I’ve ordered a sensor cleaning kit.

    Thank you all for your help.

    @randombullet@feddit.de @IMALlama@lemmy.world @Zip2@feddit.uk @superkret@feddit.de @falkerie71@sh.itjust.works @Eufalconimorph@discuss.tchncs.de

    • Gormadt@lemmy.blahaj.zone
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      1 year ago

      Happy to hear you found the problem

      After a hike I noticed some weirdness when taking pictures, turns out when I swapped lenses on the hike I trapped a mosquito between the lens and the sensor

      Good news is it just fell out when I tipped the camera

      Bad news is now I’m paranoid about there still being bits in there

  • Zip2@feddit.uk
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    1 year ago

    You might want to give your sensor a manual clean with a the appropriate swab and fluid before anything as drastic as disassembling the lens. The further from the sensor, the less visible marks are, which is what makes me think this is dirt on your sensor I’ve got lots of lenses with dust in and it makes no difference.

    • hanke@feddit.nuOP
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      1 year ago

      How easy is this to perform? Is the risk of messing up high? I don’t mind tinkering with stuff, but if there is too much risk I’d prefer just leaving it to a professional.

      • Zip2@feddit.uk
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        1 year ago

        It’s really not hard, I’ve always done all of my cameras myself. But if you’re not confident then your local camera store might be able to do it for you for a fee.

        • hanke@feddit.nuOP
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          1 year ago

          I took a look at the sensor for the first time ever. It did not look like what I expected it to. Nothing wrong, just not what I expected to see.

          What do I need to clean it? Is there any good guide I can follow?

          • Zip2@feddit.uk
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            1 year ago

            I use swabs and fluid from Visible Dust and VSGO, you can normally buy them together in kits, just make sure you get the correct size for your sensor.

            Don’t over moisten the swabs, just a couple of drops is sufficient, and don’t push down too hard on the sensor. Plenty of videos on YouTube I’d imagine.

            • hanke@feddit.nuOP
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              1 year ago

              Aah, cool. I’ll look it up.

              I’m still convinced the error is in the lens though… Since it goeas away if i open up the apreture a lot.

                • hanke@feddit.nuOP
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                  1 year ago

                  Really? I mean… If the dust is on the sensor… Does it matter what aperture I use?

              • Zip2@feddit.uk
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                1 year ago

                You might be right, have you got another lens to check your theory though?

                • hanke@feddit.nuOP
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                  1 year ago

                  No, that’s the thing. I only have the one lens. I just got into photography and got this camera second hand. It is in really good shape except for this. But yeah, ony one lens this far.

                  I’ve been wanting to get a zoom lens, but I don’t dare to buy anything since I don’t know what to look for yet. So my plan is to learn a lot about lenses and get a zoom lens when I know what to get.

  • IMALlama@lemmy.world
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    1 year ago

    Aperature is 1/number, so larger numbers = smaller aperature opening = less light coming through a lens. I agree with the others, you probably have something on your sensor. You might have something on one of the rear elements that’s causing this, but it’s less likely IMO.

    Take a look at this pair of informative, and very amusing, posts over on lens rentals talking about dust in lenses.

    https://wordpress.lensrentals.com/blog/2011/08/the-apocalypse-of-lens-dust/ https://www.lensrentals.com/blog/2015/06/i-dont-know-why-it-swallowed-a-fly-weather-sealed-lens-with-a-fly-inside/