Interesting test

[gjtoth]

I just happened to stumble upon this whilst cleaning a new CPL. I held it up and viewed my monitor through it. Now, the interesting thing is this - if I rotate the ENTIRE lens, nothing happens. BUT, if I hold it by the stationary ring (the part that's normally screwed onto your lens) and rotate the adjusting ring, I can see a MAJOR difference. This doesn't appear to work as well if I hold it up to a window or a bright light. But, hold it up to a computer monitor... works! Try it. I have a 19" Wide monitor and I used a blank page in a word processor. I don't know if this will work in front of a CRT monitor.

Just something I thought I'd pass on and let you play with.

Oh yeah... what's REALLY cool about this is, you can see if the color is evenly distributed. I found out a cheapy lens I got can't compare with a Hoya or Tiffen!

[jerryph]

This is normal because there are 2 pieces of glass that rotate individually of each other.

An easy way to imagine this is to visualize a grid on each piece of glass. As you rotate both, nothing happens, but if you rotate one, the grids fall out of "sync" with each other and cause the polarizing effect.

[gjtoth]

This is normal because there are 2 pieces of glass that rotate individually of each other.

An easy way to imagine this is to visualize a grid on each piece of glass. As you rotate both, nothing happens, but if you rotate one, the grids fall out of "sync" with each other and cause the polarizing effect.

I know it's normal. But, if you did it through a window or at a lightbulb, it appears nothing is happening. If you do it at a computer monitor (LCD) you can see the effect. I'm not saying there's something wrong or abnormal. It's just a little discovery that some might find useful to see their CPL at work.

[Snappers]

CPL, does that stand for a polarizer lens?

[LensBaby]

I think it means Circular Polarizing lense! Not sure though.

[Snappers]

Thanks Sue. I thought it was but I could not remember

[dkippen]

Gary -

I have never thought about trying this, but it's something I'm going to give a try this weekend. The new computer has a flat glass monitor so it'll be interesting to see what effect I get.

[jerryph]

It stands for Circular PoLarizer filter. It's more than just a filter because you can twist it for changing effects, I suppose.

[jonrayner]

I did wonder why the outer ring spun, thought it was weird, but didn't think any more about it, will have to have a play!

[jerryph]

Most definately.

Here is a fast way to use it...

Point it to a landscape or cityscape and make sure there is about 1/2 a frame of blue sky in the viewfinder... twist the polarizer and watch what happens to the blue sky. Oh, it helps if the sun is at a 90 degree angle to where you shoot against.

I'll let you discover the rest yourself. :)

[jonrayner]

Thanks, I look forward to trying it out.

[LensBaby]

Wow I tried this test today with the monitor and it really does show you how it works! Thanks Gary

[Snappers]

Blue sky?????????? What is that?:D

[ladyups]

Blue sky?????????? What is that?:D


:D:D I got to see blue sky for about 3 hours this morning and then it was gone...completely gone...I did get to use my CPL but I've got a long way to go before I figure out exactly what I'm doing...