nikon_jon Loc: Northeast Arkansas

Notice to all the good comments on your problem. All you guys who said she needed to use the flash to balance color. Did you look at the young man's eyes? Uhhh, is that a catch light I see there.........from a flash?

Rene'spictures Loc: me to know you to find out :)

[quote=Adirondack Hiker , and set the camera to "blinkies" to show the overexposed regions.[/quote]

amateur here, can you put it in simple terms, I see the "blinkies" with my Canon Rebel xt but don't know how to fix the problem are you gonna yell at me and tell me to get a manual or can you give me a tip? Thanks Rene

Adirondack Hiker Loc: Southern Adirondacks

[quote=Rene'spictures]

Both, as my 8th grade science teacher said "you have to read the book". But, the blinkies show areas that are overexposed. To cure this you need a faster exposure for the f/stop. This can be achieved with exposure compensation. The histogram will also bepushed to the right. Ideally, you want a histogram that drops to the baseline at each end. This is not always possible, but it must drop down to the baseline at the right (highlight) side. Underexposed shadows can be recovered, but overexposed highlights are lose forever.

Rene'spictures Loc: me to know you to find out :)

[quote=Adirondack Hiker]

Thanks, I have always taken pictures but want the best I can get. I have turned and clicked so much on my camera I'm afraid I have or will screw up the dang thing and never get a good pic. I did notice a lot of the histograms are down on the right but up on the left. I appreciate the time you've given me, thanks again :D

joec Loc: Central Texas, USA

Good reply, Nikonian. There's also a good discussion that may be a little plainer on http://www.cambridgeincolour.com (hosted in the UK, that's why colour instead of color), which has lots of good articles and tutorials as well as a good forum and a wonderful gallery of mostly night shots of Cambridge University.

Joe

lesdmd Loc: Middleton Wi via N.Y.C. & Cleveland

Two problems: The "circles of confusion" is the bokeh provided by the lens in areas that are not in focus. qa

lesdmd Loc: Middleton Wi via N.Y.C. & Cleveland

Two problems:
The "circles of confusion" is the bokeh provided by the lens in areas that are not in focus. The areas in focus are a result of the depth of field applied by the aperture being applied. When I look at your photos, the bokeh appears objectionable only in areas where the background is very bright. Be that as it may, bokeh is a product of the lens used and people spend big bucks to buy a lens whose bokeh they like. It cannot be modified for a given aperture setting but one can avoid using that objectionable setting---in your case when there are bright areas in the background. I cannot imagine fixing the problem in photoshop or in any other software without replacing everything behind the attractive subjects of you photos. I think doing so make the natural background look like a scrambled mess. When taking photos, one can minimize the effect of bokeh by taking the same shot at different aperture settings.
The "blue tint" is, as described by others, due to the influence of a blue sky. Our eyes automatically make a correction, the camera cannot. The fix is to adjust white balance either before taking the photo or in post processing.
In general, try to avoid the automatic option on the camera. One loses virtually all control when doing so.
There doesn't appear to be anything "wrong" with the lens. Every piece of glass has limitations and idiosyncrasies. Pay enough, and they are minimized by the manufacturer

OldBobD Loc: Ohio

Circle of confusion refers to the apparent size of an out of focus point in a photo. Since the lens focuses only at a specific distance, everything else is more or less out of focus - hence having a larger of smaller circle of confusion. Depth of field depends on what you consider an acceptable degree of circle of confusion.

The circles in the first photo are typical of out of focus highlights produced due to the secondary mirror of a reflex lens. I can't imagine this happening with a standard lens.

The blue color comes from skylight. Since these photos were obviously not taken in direct sunlight, the light must have come from the blue sky. Most modern cameras have a white balance setting for sky light - or it is correctable in photo editing software.

alaskanfrog Loc: Alaska

the problems with your CoC are coming from your aperture settings. The problems with the blue is that you are shooting in shade on a bright sunny day. The photos themselves are actually fairly decent and well composed, so it's obvious you took the time to set up your shots.

One way to overcome the CoC is to move further away from your subject and then zoom in to set your shot. This should help alleviate the circles you see in the background. They are more apparent because you're too close to your subject. This is creating the aperture CoC affect you see in the background.

The problems with the whites turning blue can be corrected either in post, or by setting up a "White" light reflector to bounce more light on your subjects. Also, if you have a good light kit, then by all means, use it out doors, even on a bright sunlit day. This will help to overcome the bluing you see in the whites. The blue "chroma" affect you see in the bluish halos is also aperture related and can be overcome with a good light source. Perhaps the easiest way to overcome most of the light problems is to shoot on overcast days, rather than sunny days. The overcast skies produce a softer light with no harsh shadows. To assist with overcoming the bluing you see in your whites, is the "White Balance" setting in your camera. Use your white balance on your camera, take a photo of a pale blue piece of paper and then choose "Custom White Balance" in the camera settings. Choose the photo of the pale blue paper photo and select the image as your custom white balance and the set it. A pale blue color actually serves to warm the color reproduction in your camera. This should overcome some of the blue, cool effects you have experienced. One last suggestion is to buy color correction filters for the lens to help overcome the bluing if it continues being a problem for you. Nice portrait shots, is that your family?

small_cents Loc: Ashland Ma. 01721

use a flash at all times,also it looks like the lense was cool and it fogged up ??

Bruce H Loc: Oregon Coast

would a replacement lens necessarily have the same circle of confusion or might the grinding process of each individual lens be slightly different as not to cause the problem in the same place? in other words if you had several lenses to pick from would they all exhibit the same CofC? is the CofC less as the expense of the lens rises?

Doe Loc: N, Augusta, South Carolina

I do believe the flash was used, but I was probably to far away for it to make a difference and it was really bright out. In the pictures, I was about 15 feet away from them....if I remember correctly. No re-shoots until we get together again. I'm a cropper so these pictures have been cropped. I learned if I get to close I am unable to crop to get the final product out of the photo. So I keep my distance. Thank you for your comments.

Nikonian72 Loc: Chico CA

CoC is a mathematical constant based on focal length of lens. It will be identical for every lens of same focal length.

Read the first few paragraphs of article cited in my first answer on this thread. Glance at the rest of article, but do not expect to understand it.

alaskanfrog Loc: Alaska

In addition to keeping your distance from your subject while shooting, it's also a good idea to move your subject/subjects further away from your background. This will help blur the background more and thus, alleviate the CoC affect problems you have been having.

try using a "custom white balance setting" in your camera settings menu, to overcome the bluish hue in your whites. as mentioned, a pale blue piece of paper will do nicely. most craft stores sell multicolored sheets of paper with a wide array of colors to choose from. Pale green helps with skin tone. Pale blue assists with warming up the color tone, pale tan or beige cools the colors, a bright white paper balances the colors, and an 18% gray corrects most lighting and color balance issues. You have a wide assortment of choices for your issues. good luck and hope you find a suitable solution to your issues and problems...

Doe Loc: N, Augusta, South Carolina

I agree.....my lack of knowledge when it comes to knowing how to use the f/stop, exposures, etc could have caused the circles. The purchase of the D5100 was because I wanted to make taking shots for HDR photos a little easier and the purchase of the Tamron lens was to keep from having to change out my other two lenses so often. I do have several books that I am in the process of reading. The camera, I have had a very short time and had used my other two lenses on it and there have been no issues with little (donut) circles, and because I have limited knowledge about either of these items and no knowledge about all the different effects that can happen using cameras, I was afraid I had a broke $700 lens and I was still in the time frame that I could send it back, no questions asked.

Tamron techs said they had not seen this type of effect and said to send it to them. But I had purchased a third party warranty and figured it would be better to return it to the company I bought it from for them to send a new one. When I sent the same pictures to them, they were the ones telling me about the CoC.

My problem is.......if it's me, I want to keep the lens and learn how to prevent the CoC. But if it is that the lens is broken in some way, I need to send it back. The box it came in was somewhat smashed on one side and that concerned me before I even put it on the camera.

I don't know the answer because I don't have the knowledge that everyone else has.....but when I have a bunch of people divided on what the problem is.....how do I know what is the correct answer to the problem?