1. ## Close up filters

How does the above works? Is it useful? What are the pros n cons?

2. ## Re: Close up filters

Originally posted by currahee
How does the above works? Is it useful? What are the pros n cons?
The filter is mounted infront of your cam lens to provide additional magnification. They come in an assortment of +1, +2, +3, +4, +10.

3. so wat magnification is recommended? is there any techniques to be used when using such filters to take close-up shots?

4. Originally posted by currahee
so wat magnification is recommended? is there any techniques to be used when using such filters to take close-up shots?
+4

5. if it's a +4 magnification, so how close can i take a picture if i'm using a 28mm lens, and how closeup is the picture?

6. Originally posted by currahee
if it's a +4 magnification, so how close can i take a picture if i'm using a 28mm lens, and how closeup is the picture?
How close depends on how much zoom you have. If you're using a 28mm lens, the magnification will not be too significant. The magnification goes higher with increase in zoom.

7. it doesn't really magnify but reduces the focussing distance.

8. found some info here: http://www.angelfire.com/ca/erker/closeups.html

Lens FL refers to the focal length of the camera lens that the close up lens is designed for. Use with a different lens FL may cause sharpness to suffer.
Diopters are the optical strength of the CU lens. Its focal length can be calculated by using FL = 1000/Diopters. This is also the distance that will now be in focus when the lens is focused at infinity. (A +2 diopter will bring a subject at 1/2 metre {500mm} away into focus.)

To estimate minimum focus distance convert the camera lens minimum distance to diopters and add it to the CU lens strength. So a +2 CU lens used with a lens that focuses to 1 metre will act (approximately) like a +3 CU lens and bring a subject at 1/3 metre into focus.

Another approach is to calculate magnification. Convert the diopter strength to millimeters focal length (CU FL = 1000/Diopters). Then divide the camera lens FL by the CU lens FL to get the magnification when the lens is focused at infinity. Thus a +2 CU is 500mm FL. If you use it on a 50mm lens you will get 1:10 life size. The same +2 on a 300mm lens will give you 0.6 of lifesize (1:1.66).

(the pics are not linked properly)

10. thanx for all the info...
so closeup lens actually helps to reduce the focussing distance so that u can take closer shots rite?

11. Originally posted by currahee
thanx for all the info...
so closeup lens actually helps to reduce the focussing distance so that u can take closer shots rite?
yup!

12. it will also make the edges look out of focus rite??

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