redfordl Loc: Carver,Ma.

I have a friend who has a canon t6 camera and is getting a blackish gray spot(11.9mm diam.)on the upper left side of all his images. His lens is clean etc. Is this spot from some type of smudge or dirt or whatever on his sensor? looks too large for a dust spot on his sensor. Thanks!!

MadMikeOne Loc: So. NJ Shore - a bit west of Atlantic City

Would it be possible to post a couple of the images with the spot in question? You would get much better responses.

Longshadow Loc: Audubon, PA, United States

I imagine the 11.9mm is relative to the printed size if the image.
Without seeing the result, my guess would be possible dust on the sensor IF the lens is clean on both ends.
Have him try shooting a white non-textured wall to see if it still shows up.

CHG_CANON Loc: the Windy City

Without seeing an example, I'd guess from the description your friend has sensor dust. The same spot will appear image after image in the same location regardless of lens. It may seem to differ in darkness, but not size nor location on certain images, seeming more obvious in images at aperture around f/11 and smaller.

You can google "sensor dust" or "sensor cleaning" and find a lot of discussion. The search field on the UHH pages for "sensor cleaning" should also give you several discussions of available tools and cleaning options.

The dust can be anything. I've even found pet fur on my sensor when I finally learned out to lock my mirror and see the sensor.

redfordl Loc: Carver,Ma.

here is the image with dust spot on upper right. taken at f5,iso 1000mm, at fl 80mm. Thanks,

Longshadow Loc: Audubon, PA, United States

Looks like dust (dirt) on the sensor, especially if it is also in other images.

CHG_CANON Loc: the Windy City

Run of the mill sensor dust.

MadMikeOne Loc: So. NJ Shore - a bit west of Atlantic City

Sensor dust.

CO

If the Canon T6 has an ultrasonic sensor cleaner make sure that is activated. If that doesn't do it get a filtered blower. I have the Koh Global Hepa Jet Air II blower. It has a large hepa filter, an anti-static filter, one-way check valve, and a medical grade PVC bulb. Most blowers have a rubber bulb that can shed fine particles. The PVC bulb won't do that. Adorama Camera has it and you can order it directly from Koh Global.

Purchase a filtered blower

GoofyNewfie Loc: Kansas City

Reasonable price!
https://www.adorama.com/cpkhjdb.html?gclid=EAIaIQobChMI5qOdnP262gIVyLXACh0dwQVCEAQYASABEgLNPfD_BwE

sueyeisert Loc: New Jersey

LoneRangeFinder Loc: Left field

Totally. There’s no way that’s on the lens.

Fotoartist Loc: Detroit, Michigan

I thought spot on images were supposed to be perfect.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

U need to clean your sensor.

amfoto1 Loc: San Jose, Calif. USA

Dust on or in lenses will NEVER show up as a spot on an image. A lot of dust on or in a lens can cause flare. But it takes a really large... and very obvious... object on or in a lens to actually appear in an image.

Looking at the sample image... it most certainly is dust (or whatever) on the sensor. Actually it's on a filter that sits right in front of the sensor.

The Canon T6 is their most entry-level model and that series doesn't have a self-cleaning sensor (all other Canon DSLR series do). So your friend's only options are to do a sensor cleaning themselves or pay someone to do it.

Sensor cleaning is a little risky. There are various things that can go wrong and end up doing expensive damage to a camera. Tell your friend not to do it unless they have the right tools and and supplies and are VERY sure of their abilities. Otherwise, it's worth spending a little to have the cleaning done.

The user manual (downloadable from Canon website, if they don't have a copy) describes how to set the camera for a sensor cleaning. www.cleaningdigitalcameras.com give details on the cleaning process itself and the various tools that are necessary. Your friend should read, study and fully understand every page there before trying to do a cleaning. The guys who maintain that page are professional camera repair techs. One of them literally "wrote the book"... actually many of them... on camera repair. They also own and operate www.micro-tools.com, which among other things sells virtually every sensor cleaning product made. So their info is pretty un-biased... they aren't trying to sell you a specific product like a manufacturer might, making claims about its effectiveness and superiority over other methods. Truth is, there are a number of steps to properly cleaning a sensor, using different tools. There is no single "best" or "only" way to do a cleaning... What's used depends upon the specific problem and the step in the cleaning process. Multiple steps using different products and tools in the correct sequence are nearly always necessary.

And it might be important to know... that spot in the image is in the upper, right hand corner. With lens removed, mirror up and shutter open to reveal the sensor behind it, the actual speck will be in the lower, left hand quadrant of the sensor. The image projected onto the sensor by the lens is upside down and reversed (the mirror and viewfinder flop the image and flip it right side up). Also, if that speck is making an appearance at f/5, a fairly large aperture, it must be something pretty good sized. Smaller dust specks usually aren't visible in images until fairly small apertures are used. Take some shots of a clear blue sky at f/22 and you'll see just how dirty your sensor is!

By the way, any specks seen through the camera's viewfinder also won't show up in images. Those are either on the focusing screen or on the mirror (more rarely, within the viewfinder itself). When an image is made, the mirror flips up out of the way and covers the focusing screen, before the shutter even opens. After the shutter closes, the mirror drops back down again. Specks that appear sharp in the viewfinder are on the focus screen. Specks that are blurry and out of focus are on the mirror.

Because anything on them is merely a minor nuisance and won't show up in images... other than giving them a rather gentle puff of air with a bulb blower, I don't recommend trying to clean either the mirror or the focus screen yourself. Both are somewhat easily damaged... the mirror is front-surfaced, usually with vaporized aluminum, and semi-transparent (easily scratched). The focus screen is usually optical plastic (also easily scratched or damaged by using the wrong type of cleaning fluids on it). Repairs can be expensive!