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December 09, 2018, 01:41:08 PM


Author Topic: Smudge on photo  (Read 2771 times)

Offline Jo

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Smudge on photo
« on: January 09, 2016, 01:38:47 AM »
Hi all
I am new to this forum .
And by the way Keep up the good work
I am attaching a photo to see if someone can help me out with my problem.
When I take photo of blue skies ...when lens is exposed to a good amount of light I get black smudges all over the photo.
Please can anyone help me out solving this problem if it can be solved.
Thank you very much
Desperately yours
Jo

Offline Doodle

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Re: Smudge on photo
« Reply #1 on: January 09, 2016, 07:06:34 AM »
Hi Joe, welcome to the forum!
I swear if I didn't know better, I would say it looks like someone tried to clean your glass with something wet and it dried some smudges on it! 
Normally I would say you have dust on your sensor but those aren't spots- those look like lines of some sort.
Has this camera recently been cleaned by a camera store or someone like that? Are your lens all clean?
If you have more than one lens, does this phenomenon occur with all of them?
Hopefully we will have someone on here that can give you a more definitive answer as I am just taking stabs in the dark here...
Take your camera with you dammit. You can't take your next "best photo" if your camera is sitting at home in the bag, now can you?

Offline Snapper

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Re: Smudge on photo
« Reply #2 on: January 09, 2016, 03:33:11 PM »
Welcome, Jo! :)

Sure looks like marks on the sensor to me. Has it been cleaned recently? If so, by whom and what did s/he use?

Just to check, put your camera in manual mode, narrow the aperture down to the likes of f/16-22, and set the shutter speed to around 1 second or more.

Then find a clean patch of a plain, light-coloured wall, and take a photo.

As the photo is being captured, move the camera down the wall. This way the wall will blur, removing any marks. All you’re left with is the dust on your sensor.

You should get the same marks with different lenses.

I used to be a very negative person... but then I went digital.

Offline AndyCivil

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Re: Smudge on photo
« Reply #3 on: January 09, 2016, 03:46:30 PM »
I agree with Snapper, I want to see the result of that experiment. I have a modification to the method however, please set the camera to Av mode and f-22 and choose a white wall in a medium-low light room. If the exposure time is not between 1 and 10 seconds, change the light level appropriately.

Offline Snapper

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Re: Smudge on photo
« Reply #4 on: January 09, 2016, 04:55:01 PM »
Andy - the reason I suggested Manual mode was that the camera might not achieve focus in Aperture Priority mode when pointing at a blank, light wall. ;)
I used to be a very negative person... but then I went digital.

Offline AndyCivil

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Re: Smudge on photo
« Reply #5 on: January 09, 2016, 08:27:38 PM »
Andy - the reason I suggested Manual mode was that the camera might not achieve focus in Aperture Priority mode when pointing at a blank, light wall. ;)

Oh yeah, you mean it'll refuse to take. Good point,  when I tested it, I had it on manual focus. Yeah, put it in manual focus and make sure it isn't LOL ;)