Filters?

I prefer not to put any filters on the front of my lenses, I use the lens hood for front end protection. Generally yes a poor quality filter will degrade the IQ

The thinking is that UV filters are not needed on digital cameras as their effect on film doesn’t come across on a digital sensor - don’t ask me why, I am not that technically minded. They were more often kept on for lens protection as you say, I do sometimes use them but you are probably better off with a lens protection filter, they are made of tougher glass and a good quality one shouldn’t noticeably degrade the image. I tend to go for Marumi and the pro grade Hoya filters. It isn’t just the accidental scratches etc. they protect the lens from but inadvertent damage to the coating and glass when wiping it clean, I just prefer to keep the lens absolutely pristine and not risk something costing up to two grand to replace.

Film has a tendency to have a blue cast especially when shooting under a bright blue sky. UV and Skylight filters would remove the cast which was especially important for slide film where you could not correct the image in the printing stage.

Film can only be manufactured with a specific light source in mind. Daylight film gets used in daylight right ?....but there is a wide range of colour temperatures in the daylight hours. So warming/cooling filters are used to present the film with a light temperature suited to it's specifications.

Digital sensors have very little susceptibility to these blue casts and so the UV/Skylight does nothing to benefit the image. With digital we also have control over the white balance used either at time of capture or later in PP if we want to warm or cool the image.

Generally I always try to remember to install a lens hood, not only to exclude stray light but also to protect the front glass from accidental impact damage. However, I also agree with Rob - always using a filter removes the risk of accidentally damaging the front element when cleaning. I mostly have branded filters (such as Hoya) costing around £30 - I suppose image degradation is theoretically possible but I can't say that I've noticed any.

Philip

I've run tests in the past and generally rsolution isn't much harmed by a quality filter. There is perhaps more of a chance of flare, and that was found to be the case.

More importantly, there have been instances where a filter broken whilst on a lens has actually scratched the front element.

I would not use a filter unless it were for a specific purpose that can't be achieved in photoshop. So I might use a polariser, although in practice I rarely do. I always use a lens hood as this does afford good protection to impact on the front of the lens and the front element.

Always a lens hood but never use a filter.

Why put another piece of glass in the way, especially when using long lenses ... There are enough other variables to contend with as it is.

It depends on the film and the lens. I find that Ektar is fine and does not need filtration (maybe corrected at scanning/printing stage?) but even the new Ektachrome has a tendency to have a slightly blue cast. On my Yashicamat 124G I've taken to using an 81A filter to correct it. For BW film you are using filters to change the contrasts between colours so a rather different ball game.

On my digital lenses I always used to use a filter for protection because archaeological sites are incredibly dusty and dirty. I so rarely go on site any more that I have more-or-less given up on them.

K.