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-   -   uv and polarizer? (https://www.dvinfo.net/forum/sony-hvr-v1-hdr-fx7/102646-uv-polarizer.html)

Leslie Wand September 1st, 2007 04:54 PM

uv and polarizer?
 
together - if so which in front?

or simply polarizer when needed?

basically to cut haze on landscapes....

leslie

Marcus Marchesseault September 1st, 2007 09:53 PM

I use the Cokin P filter system and it works just fine. I bought their glass linear polarizer for about $40 and it seems fine. I have a half dozen gradual ND filters and a clear resin filter for protecting the lens. It all fits in a sort of mini plastic matte box and even can fit their plastic lens hoods. I use one of their $10 plastic hoods and leave it and the filter system on all the time. I think the filters are fine, but you must make sure they are really clean if you are going to have two extra pieces of material in front of your lens with 4 surfaces to collect dust.

Leslie Wand September 2nd, 2007 12:31 AM

much appreciated marcus. will look into the cokin - was looking at formatt 600 or cavision...

all the best

leslie

Marcus Marchesseault September 2nd, 2007 06:22 AM

There is an advantage to the 4x4 filters, but they are about five times the price and have a bit of a size tradeoff. The Cokin P fits nicely on the end of the VX7 with plenty of clearance for two or three filters without vignetting. The polarizer is round and has it's own slot in which it can rotate. The whole fixture also can rotate. It's the cheapest way to have a square filter system by far.

FYI, the square filters are resin/plastic so they can scratch if you are not careful. The polarizer is glass. The great thing is that if they get scratched it only costs about $20 for a replacement. I scratched one of mine by storing the polarizer next to it with it's serrated edge touching the resin filter. The polarizer has a serrated edge a bit like a giant quarter. I think it is to make it easier to grip on the edges or maybe to help it stay put in the holder. It's hard to explain, but if you keep the polarizer on one end of the filter case and have the serration on the outside it shouldn't scratch your other filters. I got the soft Cokin filter bag and just need to remember to put the polarizer away facing the right direction.

Leslie Wand September 7th, 2007 05:10 AM

whilst looking at that, a friend in the uk just bough one of these from india:

ebay item: 120082040810

anyone know anything about it / quality, etc.,

leslie

Marcus Marchesseault September 7th, 2007 05:30 AM

Does that have a rotating stage for polarizers?

Leslie Wand September 7th, 2007 05:20 PM

apparently not, but i was thinking i could look at one of the circular drop ins, such as the lindhal on the page below, or large rotating one - but i'd be happy for your thoughts as i have no experience with polarizers on video - thought i am familar with graded ones:

http://rotpolar.notlong.com

though i am open to other suggestions if you have any. i have two main 'problems':

well three if you count budget :-)

1. one of the gigs i have is shooting race horses on studs (i love saying that to people who don't know the terminolgy), and both the horses and landscapes look much better with polarizers. especially the horses coats (i also shoot stills occasionally).

2. i'm in outback aus. and i can tell you it gets VERY, VERY bright! hence the need for good lens hood / french flag...

thanks for your time and interest,

leslie

Ed Quinto September 7th, 2007 06:44 PM

you need the rotating stage for the polarizer so you can dail in the amount you want depenting on position of your camera and the sun.

Leslie Wand September 7th, 2007 08:03 PM

other than the lindhal i looked at above, could i use a 100mm circular polariser and simply rotate it in the fixed slot?

leslie

Marcus Marchesseault September 7th, 2007 11:35 PM

You probably need to have both the mattebox and filter in your possession to know if it will work. It will depend on the way the slots and the filter are shaped. For instance, on the Cokin filter holder a plain round filter would just fall through since the slots on the holder actually hold the filter with a spring action. If the mattebox you are looking at has an actual bottom of the square filter stages and the polarizer isn't too thick to fit, it may work.

Honestly, without a rotating filter stage, a mattebox is limited in use. The most useful filters are gradual ND and a polarizer and both of those might need to rotate. A gradual ND that can be rotated to better align with your horizon or bright area of sky is more useful. Most other types of filters can be replaced with digital coloration in post.

My personal feelings are to either spend the $500 on a real mattebox with at least one rotating stage or get the cheap Cokin stuff until you can afford the best.

Leslie Wand September 8th, 2007 12:18 AM

marcus, you're probably right - i really would need to have all the bits together to see if they work properly. i was just hoping that i could get away with the fixed filter holders and use a rotating filter....

i'll have to see about stretching the budget.

many thanks for your input, most appreciated

leslie

Piotr Wozniacki September 8th, 2007 02:19 AM

I am totally new to polarizers guys, so please forgive my naive question, but: rotating is important to circular polarizers only right? Well, somewhere I read with HD camera's the non-circular ones are just as good, and much cheaper. Can it be true?

Leslie Wand September 8th, 2007 03:37 AM

hi pitor,

cut and pasted from Jim Dees /Waldemar on another thread:

What is the difference between the Polarizer and the circular polarizer ?

A circular has an additional quarter-wave plate or scrambler behind the (still linear) polarizing foil. Although not scientifically correct, it more or less restores the natural 50/50 vertical/horizontal balance of polarization, without affecting the initial pictorial result.

Only by restoring this natural balance it will allow the light metering and AF sensors to work properly, as they use polarizing beam splitters. With a linear filter, you would risk a cross-polarizing effect, ie a black-out. Bad for both light metering and AF.

In spite of what most people will tell you: the main reason to buy a circular polarizer is *not* the AF sensor, but the light metering system. You can *see* when AF goes haywire (it won't shift focus, it just has more difficulty to lock on), but you can only guess what happens with your light meter!

Actually, the first circulars were required long before AF existed, and are still required for non-AF cameras today (Rollei 600x series is a nice example).

POLARIZER TIPS

TIP #1: How much a polarizer filter will darken a sky depends on the type of sky and your shooting angle in relation to the sun.

TIP #2: On a sunny day, position your shoulder towards the sun and your subject at a right angle to your shoulder. When the sun is high in the sky, maximum polarization will result along the horizon. When the sun is low in the sky, maximum polarization will result in all areas in front of and behind you.

TIP #3: A polarizer has very little effect when used under a gray, overcast sky.

TIP #4: Remove any protective lens filters when using a polarizer.

TIP #5: Use a polarizing filter indoors only for reducing relections and glare. Any color saturation will be minimal. Remember, a polarizer filter will effectively reduce your lens aperture by up to 2 f:stops.

TIP #6: Use a polarizer filter to control depth of field. This is similar to using a Neutral Density filter, except that the Neutral Density will render "neutral" colors, while the polarizer saturates colors. Neutral Density filters are available in greater light reducing densities than polarizers.

TIP #7: To distinguish a Circular Polarizer from a Linear Polarizer, turn the filter backwards and look through it into a mirror. If the filter image in the mirror is black, you have a circular polarizer. If the image is clear, you have a linear polarizer.

Tip # 8: A Polarizer tends to cool down the image. I find adding a Warm filter will restore warmth and a more natural image.

Piotr Wozniacki September 8th, 2007 03:48 AM

Thanks Leslie for this round-up! Is there a way to effectively use a circular polarizer without rotatable holder/mattebox etc. (I know, it'd be a compromise but I don't want to invest too much in my V1 just now, with the EX1 round the corner). If so, which model/brand is good for the V1?

Leslie Wand September 8th, 2007 04:13 AM

wish i could help you out - i'm going through the same hoops, as you can read above.

i understand the principle of being able to rotate a pol. to obtain the best results for the situation (i do it all the time with stills on my nikon), but with video, well, i don't know cause i haven't got anything to play with, boo-hoo.

i'm sorta hoping that i can get a circular (physically) pol that'll drop into a fixed slot, so i could rotate it through the top. my problem with this is i really don't know who makes a suitable sized pol. the lindhal above looks on paper to be the answer, but without physically trying it, i'm loathed to part with any cash...

leslie


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