FILTERS

7 replies [Last post]
incas
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Joined: Oct 7 2000

With a Panasonic DX110 camcorder, is it worth me buying filters as listed -
1. Polaroid
2. Gradient Tobacco
3. Gradient Blue
4. UV
5. ND4

I am off to the Caribbean and want to know if it is worth spending the extra money for these? Can I not apply filters in post production on my Adobe Premiere package (gradient blue to make sky more blue, tobacco for sunsets etc) or are the results not the same

Gladders
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Joined: Apr 28 1999

Some filter effects could be done whilst editing, gradient blue and tobacco as you mention. However things like polaroid would only be effective while you are filming, cutting reflections. Neutral Density is used mainly to reduce the light entering the camera lens, thus needing a larger lens apperture and producing a narrower depth of field. UV cuts a certain amount of haze and is often used to protect the front element of the lens.

So purely colour filters can be applied while editing, UV, Polaroid and ND can not.

Having said all this, if you don't know why you are using certain filters there's not a lot of point in using them.

Paul

[This message has been edited by Gladders (edited 12 December 2000).]

Paul

Alan Roberts at work
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Joined: May 6 1999

Yes, you can get filter results in post-production, but there's a penalty.

Your camera (mine's a DX100 as well) records data in 8-bit scale, black at 16, white at 235. If you put a real filter over the lens, and don't rebalance the camera, then you'll record what you want, with white still at 235. If you just record the scene and use filters in post-production, you'll end up adjusting gains and gammas to change the white point and grey scale, and that changes the quantising and the noise characteristics. Neither need be a problem, but in extreme cases you can wreck the image quality by too much tiffling of the colouring.

It's always better to get the light on the scene right, and to get a true representation of that through the lens, rather than tweaking in post-production. BUT, if you get the camera filtering wrong, then you can't usually put it right in post-production, so you have the risk of not quite getting the effect you want, and can't acceptably undo the filtering to return to an unfiltered image.

The choice is always yours.

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alan@mugswellvillage.freeserve.co.uk. Delete village for a spam-free diet.

tom hardwick
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Joined: Apr 8 1999

I might add that although as Alan says it's best to get the footage right 'up front', the realities of being cinematographer, director, sound man, cajoler and gofer means that at the time of shooting, and for a lot of my shooting, I'm lucky if I can get enough footage shot "pure".

Post production does allow me the luxury of trying different gradient filters albeit at the expense of picture quality, but some effects (as Gladders says) can only be got at the time. One that springs to mind is slow shutter speeds, and I've not been able to duplicate that using Prem - oops, sorry Alan.

I'd go for an ND4 or ND8 Incas, as it's important to keep your 110 from using f11 or f16 from a sharpness point of view. The Polarizer will give you continuity problems on the editing bench but is a fine filter to use if you have a lot of time at the shooting stage. It'll absorb a stop and a half by the way. You won't need a circular Polarizer, they're more expensive than the linear variety.

tom.

incas
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Joined: Oct 7 2000

Thanks for all the advice. I've gone for a Cokin set for £30.00 inc adaptor onto my 43mm lens. It's unfortunate that the screw on lens rarely come in that size.

One problem I have experienced on my UV screw on lens - it sometimes catches the light and reflects so you can see your filming through a filter (might have something to be with my auto focus?). Any advice on this please. Also when sliding in and out my numerous filters whilst holidaying in Cuba (I have borrowed a whole bundle of Colin filters from a friend) should I be sure not to mix certain filters i.e Have a UC filter with a graduation? or/or not on a polaroid. I'm leaving in a few hours so please reply soooon.

Alan Roberts at work
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Joined: May 6 1999

Auto focus can be a pain. A DX100 can focus on it's front element, so a filter could be a problem. Always keep the front element (or filter) very clean, or it can focus on it. I got caught out with water droplets on the front element, I got lovely little pictures through the droplets, that were each in focus, but the rest wildly out. The effect was vfery pretty, but not what I wanted.

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alan@mugswellvillage.freeserve.co.uk. Delete village for a spam-free diet.

Gladders
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Joined: Apr 28 1999

I stopped using a UV filter on my DX100 because it seemed to slow the autofocus too much. I'm not sure if this is really the case, but there were a few occasions when it seemed to be hunting when usually very quick and accurate.

Paul

Paul

Alan Roberts
Alan Roberts's picture
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Joined: May 3 1999

Paul, that doesn't surprise me. The DX100 goes from infinity to macro (almost micro) continuously, so putting a plane in front of the lens can encourage it to focus there, on spectulars or dust or water droplets. Pity there isn't a menu setting to define the minimum focus distance, then filters would work perfectly.

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Alan Roberts

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