What are these white spots?
Nov 14, 2015 10:19:22 #
My wife and I spent the day at Bosque Del Apache yesterday, Friday 13 November. I had a rented Sigma 150-600 with me, which was great fun. However, I also had my Canon 300 f4 L which I used for some of the shots. When I pulled them into Lightroom, I noticed that on shots of hawks taken with the 300mm, there are small white spots in various random places. I was using a hood. I would have thought this might be dust,m but as you can see for two attached images taken in sequence, the dots don't appear in the same place but seem to be random. I would think if it was dust on the lens or the sensor, they would appear in generally the same place relative to the frame.
Anyone have any idea what might have caused these random white dots?
Anyone have any idea what might have caused these random white dots?
Nov 14, 2015 10:27:02 #
Nov 14, 2015 10:33:50 #
Take a photo of a white wall at f16 or f22 etc. (ie your smallest aperture opening.) If you see dark spots in place of the white ones, it's specks of some kind of "dirt."
Nov 14, 2015 10:45:01 #
It looks like some dust specs on your sensor, depending on the opacity of the dust spec they can show up as light or dark spots on your images. They are easily removed in photoshop or lightroom. You may want to try the cleaning function of your camera or use a rocket blower if the camera function doesn't help. Should those two methods fail to remove them, then using a sensor swab or taking it to your local camera shop for a cleaning may be in order.
Nov 14, 2015 10:48:20 #
Nov 14, 2015 10:55:20 #
jeep_daddy wrote:
Dirty sensor.
That's what I thought too but they only show up with this lens. (Plus its a fairly new 7DM2). I thought of internal dust but why would they appear at different places in the field of view? Seemingly at random.
Nov 14, 2015 11:24:21 #
If you don't find when you test under other conditions, they might be insects. There is a rather feathery-looking flying insect in abundance in one location where I shoot and these resemble.
Nov 14, 2015 11:36:19 #
Linda From Maine wrote:
If you don't find when you test under other conditions, they might be insects. There is a rather feathery-looking flying insect in abundance in one location where I shoot and these resemble.
That sounds like a likely cause! By the way I did try shooting a white wall (actually a large piecer of white poster board), in daylight at f22 as suggested above. No dark spots observed - looks clean as a whistle. I think the idea of insects makes sense, given that there are a lot of critter flying around. That would account for why they are not in the same locations in the frame from shot to shot.
Nov 14, 2015 11:38:16 #
Since they are not in the same position you can eliminate:
- sensor
- 'stars'
- anything slow moving
You are left with a few choices:
- seeds
- insects
- spiders
I had a similar problem in the spring. The best bet was insects.
- sensor
- 'stars'
- anything slow moving
You are left with a few choices:
- seeds
- insects
- spiders
I had a similar problem in the spring. The best bet was insects.
Nov 14, 2015 12:27:12 #
Looks to be airborne seeds aloft on the same thermals the bird is using.
Mike
Mike
Nov 14, 2015 12:59:44 #
Put any lens you have on your camera and stop it down to f22 or something small like that. Take a picture of the bright blue sky. Overexpose it as much as you like but make sure you don't have it underexposed. Then download and zoom in. Do it with several lenses and see if the spots are in the same general location. You might just have dust on the mirror and you could try a jet blower to blow it off.
Nov 14, 2015 13:08:51 #
jeep_daddy wrote:
Put any lens you have on your camera and stop it down to f22 or something small like that. Take a picture of the bright blue sky. Overexpose it as much as you like but make sure you don't have it underexposed. Then download and zoom in. Do it with several lenses and see if the spots are in the same general location. You might just have dust on the mirror and you could try a jet blower to blow it off.
Dust on the mirror? How would that show up in the image?
Nov 14, 2015 13:16:05 #
Basil wrote:
That's what I thought too but they only show up with this lens. (Plus its a fairly new 7DM2). I thought of internal dust but why would they appear at different places in the field of view? Seemingly at random.
The insects theory is interesting.
Dust can move around.
If it is only with this lens that you see the spots then it would seem there could be dust or debris inside the lens. Hold it up to the light and look inside.
Nov 14, 2015 13:20:22 #
Dust on a mirror does not affect the picture as the mirror flips up to allow light to strike the sensor. Dust on the lens or sensor prevents or inhibits the transmission of light, and present as dark spots on your picture. These are lighter colored spots, probably caused by malfunctioning pixels on the sensor. They are referred to as hot spots. or hot pixels. you can create a preset correction for them in Lightroom or Photoshop, because they don't move. Depending on the background/shot a hot pixel may be more or less visible, but it is still in the same spot.
Nov 14, 2015 13:21:10 #
photoninja1 wrote:
Dust on a mirror does not affect the picture as the mirror flips up to allow light to strike the sensor. Dust on the lens or sensor prevents or inhibits the transmission of light, and present as dark spots on your picture. These are lighter colored spots, probably caused by malfunctioning pixels on the sensor. They are referred to as hot spots.
He has said the problem happens only with that one lens.
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