5D III w/100 MACRO - Background "Specs"

[tbh1930]

Looking for some help.....this is a crop of a photo taken that has specs showing up on the black background.

5D III w/100 Macro
Tv 3.2
Av 32
ISO 3200

Any commnets or help will be appreciated.

[Drizzt321]

Why are you at ISO3200 and f/32? I'd guess f/12-16 would work just as well, and you could easily go down to a lower ISO, and possibly faster shutter speed as well.  *Note, I'm not a product photographer, so I don't know if that is normal

That being said...maybe a few specs of dust in the air that reflect the light just right onto a sensor that has it's ISO bumped up pretty far? Maybe some dust on or in the lens/sensor?

[tbh1930]

Purely experimenting with a whole range of camera settings in natural light. Looking at image quality out on the "edge" and ran into these specs showing up on the black background. They range in color and brightness when observed at 100%.

Just wondering if there is something to be concerned about with the sensor.

Example below:

[Drizzt321]

Interesting...

Not being an expert, could it have something to do with diffraction and/or chromatic aberration at such small apertures? Have you tried taking a shot like that against a white or gray background and seeing if the same locations have spots like that? Or a long exposure with the lens cap on?

EDIT: Where's Neuro when you need him

[thesirren]

I have some of those myself, a red one and a couple of blue ones.
It is the dust on the sensor I believe. Sooner or later almost everyone is bound to have those. Unless pixel is dead black or dead white then it is of not much concern and should be fixed when you eventually are going to have the insides cleaned. This kind of thing manifests itself usually on higher f/'s, so people who shoot strictly portraits or within the f/4 probably would not even notice it. Much more common to be a concern for landscapers. As far as I know Photoshop automatically desaturates pixels like this. And you could program your camera for automatic dust deletion too (refer to the manual, "Dust Delete Data").

PS: some people say that using "Manual Sensor Cleaning" option in the menu's and leaving the mirror locked for 30-60 seconds and then turning the camera off helped with this, but I did not have that much luck with it.

[neuroanatomist]

They look like hot/stuck pixels.  The manual cleaning step described above is supposed to remap the hot pixels.

[PixelReaper]

They look like hot/stuck pixels.  The manual cleaning step described above is supposed to remap the hot pixels.

+1

definitely look like hot pixels.  My 5D II has 15-20 of these.  if you use LR or DXO t=you will not notice them in the output files