Doe Loc: N, Augusta, South Carolina

I am soooo disappointed right now......

I just purchased the Tamron 18-270 lens and used it this Thanksgiving to take some family pictures. When I downloaded the pictures, the background was loaded with little circles. (I will post a pic) I contacted Tamron and sent them some pictures and they said they hadn't ever seen that before and said I could send it back for a replacement. But, I had purchased it from another place and bought a warranty, so I figured I would see what they wanted me to do. After contacting B&H and sending them the pics, they told me that there was nothing wrong with the lens, that what I had was called "circles of confusion".

I looked it up and I have no idea how to correct an effect like that, so I am returning the lens. I am not educated enough in the field of photography/cameras/lenses to know how to keep this from happening and I am soooo disappointed because I really liked having the option of not changing out lenses that often.

But, before I send it back I thought I would see if anyone on the forum could maybe tell me if there is an easy way to prevent this from happening. I hate to admit this, but I was using AUTO. I didn't want to make any mistakes, so I thought I was playing it safe taking the pics on auto.

Anyone have any thoughts on the problem???????

70mm * AF-S * F/5.6 * 1/200 * AUTO * Metering-Matrix * ISO auto 280




I am able to mask it blurring the edges

Doe Loc: N, Augusta, South Carolina

Also, in the last pic taken with my D5100, I noticed that the whites look blue. How can I fix that??????

I really appreciate any information or thoughts on these two problems.

chapjohn Loc: Tigard, Oregon

It appears that those "circles of confusion" are a matter of aperture. You can either open the aperture more creating little to no definition in the bokeh or close the aperture more to get clear DOF all through the picture.
It seems that many people struggle for a long time to get the effect you did the first time with a lens.
It doess not appear to be a problem with the lens or the camera, maybe some more learning by the photographer. This lens that you are referring is well liked by many.

Nikonian72 Loc: Chico CA

First, the term is "circle of confusion" (CoC). It is not plural. It is also called "disc of confusion". Every optical lens demonstrates CoC. Read the first few sentences here, but do not get bogged down in all of the technical jargon and math:
http://en.wikipedia.org/wiki/Circle_of_confusion

CoC does not produce artifacts in photographs. The artifact in your photo is a ring pattern highlight, similar to what is normally produced by a "Reflex" or mirror telephoto lens. It should not happen with your zoom lens.

Tamron was correct; who ever replied to you from B&H was wrong! Persons (such as a few photographers on UHH) with a little bit of knowledge can cause more damage than someone with no knowledge.

Time is now, to send your lens for repair or replacement.

Nikonian72 Loc: Chico CA

The blue cast is from the sky acting as your fill light. Consider using a camera-mounted flash to provide your fill light. You need just enough flash fill to color-temp match (your shaded subject) to natural sunlight.

Doe Loc: N, Augusta, South Carolina

I wish everyone would take a second to just check out the webpage you suggested to look at but not get bogged down in. LOL That is what I started reading when B&H sent me the email telling me what they thought it was and I said to myself......"oh, this is way over my head"! I wouldn't have a clue how to correct it.

So, you are saying it is broke in some way?

Doe Loc: N, Augusta, South Carolina

and I wanted to be one of those who liked the lens as well..... If I had it on "auto" wouldn't the camera set the aperture correctly?

I want nothing more than to be able to have the 18-270 lens. But I need to know if it's broke or if this is the way it works. Do you have the lens?

chapjohn Loc: Tigard, Oregon

I agree with Nikonian72. Please disregard what I wrote earlier. Please also note that I started that reponse with "It appears..." meaning that I am willing to corrected.
I made some conclusions because I thought you were shooting manually. Now knowing that you were in auto mode would have changed my answer.

Nikonian72 Loc: Chico CA

I am not a repair person, so I cannot diagnose specific problem. That will be the job of repair facility covered by your warranty. Include a photo when you return lens for repair. INMO, your lens needs a bit of TLC.

Doe Loc: N, Augusta, South Carolina

Thank you both so very much for taking the time to try and help me with this....I really appreciate it.

Danilo Loc: Las Vegas

Look again, Doe, that blue cast is in the skin tones of your subjects as well. You could probably correct this in photoshop, or GIMP.
I do, however, like Nikonion72's idea better, use a flash to provide the correct color of light, overcoming the cast from the sky. It would also put a "sparkle" in the people's eyes that would be quite pleasing. Of course, you'd have to re-shoot the set...bummer!
Very nice work, though, well worth perfecting!

Adirondack Hiker Loc: Southern Adirondacks

Lets start with the last photo, then go to the first. The blue tint is because of an incorrect white balance, set too cold. This is why I never have any of my camera settings in AUTO. If you have Elements, it is an easy fix. Go to correct color cast and click on the shirt, it will turn white. I normally leave my white balance in CLOUDY, and since i shoot in RAW, can fine tune it.

Now the first photo. First off, the circle of confusion has to do with calculating the depth of field, not artifacts on an image. For example, the D5100 has a CoC of 0.02, non full frame Canons are typically 0.018 and a point and shoot about 0.005. The "circles" appear to be overposed patches of light. Because of the f/stop setting, the depth of field is very limited, and they are severely out of focus. If it was a lens problem, the circles would also be on the people, but they are not.

I find it amazing how often the first thing people say, especially beginners, when an image is bad "its the lens", when in fact 99.99% of the time it is pilot error. You spent a lot on the camera and lens, invest another $25 on some good manuals, Amazon has many used in great shape for little cost. Learn the relationship between f/stop and depth of field, the best ISO (normally 200 for your camera), most important how to read the histogram, and set the camera to "blinkies" to show the overexposed regions.

Dria Loc: Ohio

1st--your arrangement of the people and their expressions are wonderful so I would do my darnedest to correct the flaws.
I am not a photoshop wiz so my fix would be to use the soft sponge and dab over those area circles to soften and blend them.
I have the Tamron 28-300 ( I got it 2 months ago) and I have never had it do that -- or the setting I use have never produced that..what ever way you look at it--
I tend to think it needs to be replaced.
Perhaps Tamron would like to get it from you directly so that they know what they are looking for with it -- some companies like to actually look at products that produce and "odd flaw" so they can see what went wrong.

LoneRangeFinder Loc: Left field

Nothing to add to the "circles of confusion" convo....
To add to Nikonian's suggestion regarding a fill flash: You might also "slave" a backlight to help separate the dark hair in photo #1 from the dark background.

nikon_jon Loc: Northeast Arkansas

I agree with Nikonian. Those circles should not be there. They are one of the problems people experience when using mirror lenses. One of the reasons that mirror lenses didn't make it big in the photography field.

I would like to comment on another problem I see. Develope the habit of looking all around the frame before hitting the trigger. It will help you avoid distracting things in the background. In the head shot of the young man, I saw a huge patch of light sky on his left side. Light or white objects draw the eye and can be very distracting.

Missing this kind of thing happens because we have a brain. The brain picks out a few things about the scene or person we are photographing, it says, "Ah, yes, I know that person, or whatever" and then it dumps the rest. So we sometimes don't notice things we would rather not have in our pics. The camera, however does not have a brain so it faithfully records EVERYTHING in front of it. In my younger years I would get pics of people who looked like a moose or deer. How so? There would be a branch from a nearby tree or bush that was right behind the head and looked like antlers growing from their skull.

It takes practice, but try to get into the habit of NEVER pushing the shutter button without starting at the top left corner and going all the way around the frame with a good look before you shoot.

BTW, I love your composition in the third pic you posted.