Newbie question on lens

[Eugene]

Hi all,

Dun mind my ignorance...
Hope somebody can answer my questions....

1. For close up filters, why do they sell packages of +1, +2, +4,
For better close up, can't they use +4, +4 , +4? or more +10?

2. Wad does it means when a lens vignet? wad causes it?

Thanks!


:what:

 

[mervlam]

i will answer only the second part.. hehehe.... dunno the first part yet...

vignetting is caused by barrel distortion of the lens especially in high ratio zoom lens eg 28-200mm. it can also be caused by a lens hood that is too long for the lens

vignetting will caused the cutting off of the image at the edges and corners

 

[Flare]

Vignetting... imagine looking through a toilet roll, the roll blocks out some of your view, that's vignetting. To add to mervlam, wide angle lens can have problems with even filters as the metal edge of the filter 'blocks the lens' Sometimes it may not be very obvious but just look like darkening around the edges...

 

[Eugene]

Thanx! now i get it...
so anyway to prevent this?
get a good lens?
lol

:what:

 

[mervlam]

Originally posted by Flare
Vignetting... imagine looking through a toilet roll, the roll blocks out some of your view, that's vignetting. To add to mervlam, wide angle lens can have problems with even filters as the metal edge of the filter 'blocks the lens' Sometimes it may not be very obvious but just look like darkening around the edges...

nice description :thumbsup:

 

[munfai]

in answer to your first question...

having a choice of 3 magnification levels are far more versatile than just 1. you can mix and match +1, +2, +4 to get different dioptre levels.

 

[Eugene]

Originally posted by munfai
in answer to your first question...

having a choice of 3 magnification levels are far more versatile than just 1. you can mix and match +1, +2, +4 to get different dioptre levels.

thanx for commenting...

ic... another question is if i wan the max magnification, is it ok to use a couple of +4 close up filters?
Thanx

:what:

 

[munfai]

Originally posted by Eugene


thanx for commenting...

ic... another question is if i wan the max magnification, is it ok to use a couple of +4 close up filters?
Thanx

:what:

I suppose so, but watch out for loss of sharpness around the edges. the highest i've tried is a +2 and a +4 together.

Personally I don't like close-up filters, but they're the cheapest solution, so...

 

[Eugene]

Originally posted by munfai


I suppose so, but watch out for loss of sharpness around the edges. the highest i've tried is a +2 and a +4 together.

Personally I don't like close-up filters, but they're the cheapest solution, so...

Thanx for the quick reply!
got budget mah... quite ex macro lens...
=P

:what: