What is the best Digital SLR camera out at the moment? (Under 拢500). I am replacing a Dynax 60...?

You may have some dust inside the lens. But usually, that won't give you the well-defined dark spots like we see in your flickr picture. Most likely, you have dust on the sensor of the XTi...

An aspheric lens eliminates spherical aberration. A single aspheric lens can also replace a much more complex multi-lens system, resulting in a device which is smaller and lighter, and possibly ch...

there is an app called video camera in iphone installer try it as i am using that and it work for me

Max zoom on your camera is indeed too much for standard portraiture. Focal lengths between 80mm and 105mm are the most common for portraits. If mm numbers just confuse you, take some time to lear...

You could get a 27mm-37mm step-up ring and then get a 37mm-52mm step-up ring but I can't vouch for the picture quality, focus, reliability of this setup or other issues. I would suggest gettin...

now THAT'S a great question! i've always thought of the text books that show the eye and how intitially, the image is seen upside down in the eye. but then the image, from two points in t...

Artists find them amazing because they are so poorly made, they can expect some amazing serendipitous images caused by camera leaks, the poor plastic lens and the fact that there is vignetting on t...

I think you were using the correct equation, so you probably got the correct answers. Just make sure all the distances are in the same units. a) using your equation I got 35.1229 mm. The answe...