Filters

[Kerry]

Reading up on taking shots against water, it said that I need a polarizing filter; is it as simple as just buying any or are there particular ones that I should look for if I want to photograph things like toad spawn and water insects?

many thanks
Kerry

[nightshade]

There are rotating filters for lenses where the extending portion rotates as you zoom or focus you can then twist the filter progressively until you take the glare off the water or whatever
I hope this is clear enough

[Kerry]

Originally Posted by nightshade

There are rotating filters for lenses where the extending portion rotates as you zoom or focus you can then twist the filter progressively until you take the glare off the water or whatever
I hope this is clear enough

Yes thank you. I made enquiries this morning but at around £40 that one will have to wait for the moment. Another to add to my wish list.

Kerry

[HowlinWolf]

The type of polarizer you need depends on whether your camera auto-focuses or not, and to some extent, the metering system it uses (check your manual for advice). Modern auto-focus systems require a circular polarizer (nothing to do with the physical shape), so make sure you get the appropriate one for your camera. Also, they will loose you around two stops of light when producing the greatest effect, forcing lower shutter speeds, larger apertures or higher ISO settings. It can also produce a slightly cool cast to the image, but this can be compensated for in a suitable editing software program. Having said that, a polarizer is a very versatile filter.

HW

[Kerry]

Originally Posted by HowlinWolf

The type of polarizer you need depends on whether your camera auto-focuses or not, and to some extent, the metering system it uses (check your manual for advice). Modern auto-focus systems require a circular polarizer (nothing to do with the physical shape), so make sure you get the appropriate one for your camera. Also, they will loose you around two stops of light when producing the greatest effect, forcing lower shutter speeds, larger apertures or higher ISO settings. It can also produce a slightly cool cast to the image, but this can be compensated for in a suitable editing software program. Having said that, a polarizer is a very versatile filter.

HW

Thanks HW for this extra info. I was assuming that the lens was the important bit rather than the camera. I will be using a Canon 400D with a Sigma 105 lens.

Kerry

[HowlinWolf]

Sorry, Kerry, I'm not familiar with the Canon 400D, but I'm sure there are those that are on the forum. It's just a matter of time before someone chips in. However, I do use the Sigma, and it's an excellent optic.
There is more to a polarizer than I mentioned in my reply. Read up as much as you can to form a more comprehensive picture on the subject.
Good luck.

HW

[Kerry]

Originally Posted by HowlinWolf

Sorry, Kerry, I'm not familiar with the Canon 400D, but I'm sure there are those that are on the forum. It's just a matter of time before someone chips in. However, I do use the Sigma, and it's an excellent optic.
There is more to a polarizer than I mentioned in my reply. Read up as much as you can to form a more comprehensive picture on the subject.
Good luck.

HW

Thanks HW. I have obtained lots of books on photography from the library and I am slowly working my way through them, or quickly with some as they are pretty pictures but not much else. It is a steep learning curve for someone like me that has only ever been used to point and shoot cameras.

Kerry

[Kerry]

I have been looking round at polarizing filters and wanted to know if I need to buy a Sigma one as I have Sigma lenses or will any 58mm do? The price difference is quite large but I don't want to go for the cheap one and discover that it is no good. This is one site that has some:

7dayshop.com - Online Store

Looking at a Sigma the cheapest price that I have found is £37.

Any advice gratefully received.

Kerry

[nightshade]

Try this chap
Cokin A Series Filters from Denton Photo Optics
Hoya are probably the best but they are all (glass filters)
made to an international standard, just have to shop around
There are square plastic filters but these need a holder etc.

[nightshade]

Some of the american sites suggest using polarizing film
I do not know of any suppliers and would suppose it needs
holders and would have a short life
Linear Polarizer,Sheet Polarizer Film,Polarizer Sheet - Polarizers