Camera Labs

I'm feeling creative and have been looking at shots with filters applied. However, I don't quite understand how to choose the right filters, mounting system and other associated possibilities. I've got a few queries if someone would be good enough to answer...

1) I first started looking at CPL filters to increase colour saturation or bright days. I don't want to spend £30-60 on a 58mm or 66mm filter for either of my two current lenses and do not want to buy again for each further lens. I see this as a limitation with circular screw-in filters, so my question is;
- are square filter systems any different?
- how do they fit to my lens?
- can I transfer the system to another lens?
- do you leave lens hoods installed?

2) What types of filter do I need to;
- selectively darken a sky? i.e. control a washed out sky
- block all bar one colour? i.e. only yellow and all the rest in B+W
- completely manipulate colours? (ive seen blue rivers and gold skies, no editing)
- enhance B+W photography (i read that red filters can increase contrast)
- what else can you do?

3) Can I stack up square filters in a holder?

4) Can I rotate square filters in their holder? i.e. to allow CPL rotating)
- if I'm using a GND, can I turn it through 180?
- Is there an ideal angle for the filter to be positioned at?

5) Can you get square filters for UV, polarising and fluorescent? Can they be stacked alongside colourising filters?

6) Is there a correct order for the filters to be stacked? How many can you wedge into a holder? Can you position them in various places in the holder?

Any general shopping links?! Cases, brands?

Oh the questions, please help me to learn!

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Lots of questions, so I'll start with number 1!

Circular polarisers can be bought as screw in filters or filters as part of a filter system (Lee, Cokin etc).

An easier way is to buy 1 good circular polariser that's as big as your largest filter thread. Then you can buy step up rings to make your 1 good polariser fit all you lenses.

That's the screw in option covered.

It's a similar principle for circular polarisers for the Lee or Cokin systems - you buy the one circular polariser and the filter holder needs adapter rings for each of your filter thread sizes.

Screw in C-Pl - it's possible to use the lens hood (difficult to adjust though) if you're using for example a 77mm C-Pl on a 77mm thread lens. If you're using a step up ring the the hood may well not fit.

Lee or Cokin system - you're not going to use your lens hood, but you can buy bellows where filters drop into the 'hood'

At the moment, Lee filters are horribly out of stock everywhere and the company is not willing to compromise quality to meet the demand. They are training new staff to help increase output. They're the only square/rectangular filter system I would use, and I'm going to invest when they are available again.

It is a big investment, but one I only want to make once, and cheaper options may result in you not being 100% happy with the output, requiring a further investment in the future.

I'd recommend a circular C-Pl from a good manufacturer (B+W, Heliopan, a good Hoya etc) as a starter, and take things from there.

Number 2

To selectively darken a sky you have two options - digitally or optically. Why not try digitally to start, with multiple exposures for sky and foreground and then blending in software.

Optically, you have graduated ND filters. I wouldn't advise screw in as you are limited in where the effect appears in your frame. That leaves square/rectangular filters as your option. Again, this can be part of a system (lens adapter, filter holder, filter) but the availability of good Grad NDs is poor at the moment. Why not try to buy a cheaper version, without the filter holder and lens adapter, and handhold.

You have several versions, soft grad and hard grad, which differ in the transition from clear to dark. You then have several different densities - 1 stop, 2 stop, 3 stop.

Completely manipulate colours? If you want to do that you're going to be investing in a lot of filters for an effect that will age very quickly - I'd recommend software if you REALLY want to do that!

Enhance B+W photography. I would recommend getting a trial version of Nik software's Silver Efex. This is a good convertor to B&W, with lots of presets, and you can see the effect of using different coloured filters in darkening skies, intensifying foliage etc. That will give you a hands on view of what coloured filters can do for free before you invest, on your own photos - priceless really.

Hi Phil, thanks for tackling that monster question!



So if I buy the large screw-in CPL filter and a number of adapter rings (allowing me to use the CPL filter on multiple lenses), will I still be able to fit a square Cokin or Lee holder? Will I be able to rotate the CPL filter independently of the square system?



Would I be correct in assuming that the step-up ring, the CPL filter, the Cokin or Lee adapter and the filter holder would pretty well act as a hood anyway?



What are bellows?



I'll have to give it a go in the interests of learning, but I'm of the attitude that I want to do as much as I possibly can out in the open with optical equipment rather than spending more time that I already do in front of a monitor! haha.



I take it the effect is the same as applied in the HDR technique? You're basically using a filter to physically apply 1 (or 2, or 3) stop's darkening effect?

Regarding B+W, it's not something I do often so won't be spending much time either taking or processing, but it's good to know about that software, cheers.

I've had a look through Cokin's website and youtube videos since I last posted, so I've got a better idea of how the assembly fits together.

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