What's happening? These are the first shots with a Tamron SP 45 1.8 on a Canon 5D iv. Does anyone have any idea what is causing the ring? It disappears at 2.8, but is there from 1.8 to...

terpfan Loc: central coast, California

These are the first shots with a Tamron SP 45 1.8 on a Canon 5D iv. Does anyone have any idea what is causing the ring? It disappears at 2.8, but is there from 1.8 to 2.8. Same result with a B&W UV filter which was removed for the enclosed photos. I've never gotten anything like this with any other lens. Is lens defective or am I doing something wrong? Same result outside as inside. Thanks in advance for any solutions.

mwsilvers Loc: Central New Jersey

Did you have a lens hood or any filters mounted on the lens? If so, take them all off and try again. Also try a different lens just to make sure it's not an issue with your camera. It is a very strange effect. Never seen anything quite like it. Do you have another body to try the lens on?

CO

I have that same lens but in the Nikon version. I use it on my Nikon D750. I've never seen that happen. I just got it out and took this photo at f/1.8. I'm puzzled with that one.

Tamron 45mm f/1.8 SP VC lens on Nikon D750 @ f/1.8

(Download)

rook2c4 Loc: Philadelphia, PA USA

Do see any part of the ring when looking through the viewfinder?

ggab Loc: ?

terpfan wrote:

These are the first shots with a Tamron SP 45 1.8 on a Canon 5D iv. Does anyone have any idea what is causing the ring? It disappears at 2.8, but is there from 1.8 to 2.8. Same result with a B&W UV filter which was removed for the enclosed photos. I've never gotten anything like this with any other lens. Is lens defective or am I doing something wrong? Same result outside as inside. Thanks in advance for any solutions.

Send it back

terpfan Loc: central coast, California

Nothing in the view finder. Other lens 24-105 OK, this lens fine on 7D ii (crop sensor). It's brand new so maybe I should return it to B&H for another one. No filter or anything on the lens.

Grahame Loc: Fiji

mwsilvers wrote:

Did you have a lens hood or any filters mounted on the lens? If so, take them all off and try again. Also try a different lens just to make sure it's not an issue with your camera. It is a very strange effect. Never seen anything quite like it. Do you have another body to try the lens on?

I'm thinking anything such as lens hood/filter is going to show up well out of focus. This ring is sharp, strange.

CO

You could probably email that photo to B&H to see if they know why it's doing that. They will definitely exchange it for you.

JD750 Loc: SoCal

That is just odd. I am sorry I don’t know Canon nomenclature, but just a thought, by chance are you using a crop sensor lens on a full frame body?

You say it is only a problem from f1.8 to F2.8 so it would seem that on your camera that is an F2.8 lens.

Maybe check and see if there are any firmware updates to camera or lens.

CO

JD750 wrote:

That is just odd. I am sorry I don’t know Canon nomenclature, but just a thought, by chance are you using a crop sensor lens on a full frame body?

You say it is only a problem from f1.8 to F2.8 so it would seem that on your camera that is an F2.8 lens.

Maybe check and see if there are any firmware updates to camera or lens.

It's a full frame lens. I shot the photo above with that lens (Nikon version) on my full frame Nikon D750 at f/1.8.

JD750 Loc: SoCal

The Canon version seems like there is a camera-lens incompatibility. Maybe contact (email) Tamron about it and send them your detailed hardware info, including firmware version, see if they have any suggestions.

Use the D750 in the meantime. 🙃

jerryc41 Loc: Catskill Mts of NY

You could keep the lens and use it for special effects. Costly special effects, though.

BB4A

I can only apply logic and engineering common sense, as I don’t know this lens. It appears to have been assembled with one or more lens elements either in a (a) pre-finished or (b) ship to assembly state. If I had to guess, I’d go with (b); someone inadvertently forgot to remove all of the surround packing and protective film on one lens element, when they assembled the lens? That would explain why there’s a perfectly focused ring around the edge of the picture, that can only be seen at the lowest f numbers.

pauldh Loc: Melbourne, Australia

disable peripheral illumination correction and it will fix your problem.

CO

BB4A wrote:

I can only apply logic and engineering common sens... (show quote)

This sounds like the most probable cause. Probably some protective film or some coating that is causing that.