Lens protection.

[daredevil123]

daredevil123 provided you with a very good explanation on the usage of CPL filters. They are meant to reduce light entering the camera.

THat is not what I said...

I said when you use a CPL, you lose light... but the purpose of CPL is not to reduce light... the reduction of light is a side effect.

Please go through this very simple presentation to understand what a polarizer really does.
http://www.colorado.edu/physics/2000/polarization/index.html

 

[knockyPole]

You do not leave a CPL filter on your lens all the time. By doing so you are effectively reducing your camera's low light capability. CPL is the type of filter that you put on only when you need it. But that is me. Maybe you find some weird thrill from having a CPL on your lens all the time... :dunno::dunno:

BTW, normal CPL reduces the light coming into the camera by 1.5 to 2 stops. HRT is claimed to be higher transmission, which probably means you lose around 1 stop. This means, if you are shooting indoors, to get the same shutter speed and aperture, you need to increase your ISO by 1 stop... meaning without your CPL,. when ISO800 is enough... with the CPL on you will need to bump it to ISO1600 for the same exposure... Buy camera with good high ISO performance, only to handicap that performance with a CPL infront of the lens all the time. So you decide... is it a good thing or not?

No, too imprecise. ND / GND are meant to simple reduce all incoming light. CPL is selective.
CPL filters are meant to cut off lights which do not belong to a certain polarization level. As a result, the light of defined polarization level passing the filter will give a certain image. This gives the possibility to select those parts of incoming light that form the desired image. Examples: reflections in water or on glass that can be cut off or left in; vegetation appears differently; clouds appear more 3D like.

thanks! ahhh I totally forgot even I have my UV protection for my lens yet the filter is with CPL. so my indoor shots and videos will be badly affected!

thanks!

I will get one UV filter soon! just asking, i could just get the basic HMC Hoya UV filter will do right? Thanks again!

 

[bruggink]

THat is not what I said...

I said when you use a CPL, you lose light... but the purpose of CPL is not to reduce light... the reduction of light is a side effect.

Please go through this very simple presentation to understand what a polarizer really does.
http://www.colorado.edu/physics/2000/polarization/index.html

Ok lah.. my bad, my bad.. Apologies for that. As long as TS got the help and answers needed, I'm happy.

 

[daredevil123]

Ok lah.. my bad, my bad.. Apologies for that. As long as TS got the help and answers needed, I'm happy.

As long as you learn as well. It seems u can use some reading as well. You should check out this thread called "newbie guide to filter". You can find it in the newbie's corner.

 

[SnagIt]

Don't bother about UV filter. It deteriorates your image especially at night you can see ghosting (Not real ghost). Just be careful using your lens and you're done. People can argue if they drop the lens blah blah... for me in that case much of damage is the elements inside lens not the front glass. Not sure if filter can help your lens in this case

 

[knockyPole]

I know that UV filter helps to prevent UV lights enter the lens from the sun etc.

but if indoor, there only lamp light etc, UV filter is kinda of useless right? And it will affect the images to become worse especially when the light is very little like at nite? like what SnagIT has said?

Don't bother about UV filter. It deteriorates your image especially at night you can see ghosting (Not real ghost). Just be careful using your lens and you're done. People can argue if they drop the lens blah blah... for me in that case much of damage is the elements inside lens not the front glass. Not sure if filter can help your lens in this case

thanks alot for the advice!

 

[Octarine]

I know that UV filter helps to prevent UV lights enter the lens from the sun etc.

And why? protecting the sensor from sunburn? :bsmilie:
The coating of lens elements blocks UV and finally the sensor is not sensitive to UV. Doesn't make any sense in terms of UV to put that filter thingy there.

but if indoor, there only lamp light etc, UV filter is kinda of useless right? And it will affect the images to become worse especially when the light is very little like at nite? like what SnagIT has said

Not only that normal lamps don't emit any UV, lousy filters tend to create flare and ghosting. As long as the filter is clean the blocking of light is hardly relevant. But the reflections of light at the plain surface become very obvious in low light conditions with single light spots in the frame or just outside of it.
Lenses were designed to work perfectly fine without any filter. One cannot improve a lens by adding another piece of glass that was never meant to be there in the first place.

 

[daredevil123]

I know that UV filter helps to prevent UV lights enter the lens from the sun etc.

but if indoor, there only lamp light etc, UV filter is kinda of useless right? And it will affect the images to become worse especially when the light is very little like at nite? like what SnagIT has said?

Sensors in Digital camera sensor is not affected by UV light. Only film is affected.

And when shooting at night, especially night scenes, remove your filter.