Skylight filters - Y or N?

[John Orrell]

Just wondering what the general consensus was on skylight filters, i.e.: do you think they adversely effect the quality of your photos?

On the whole I leave the filters on permanently, as most photo books advise you to, but I've often wondered just how much this effects the overall quality of photos, especially if you've got a really hi-definition lens with slow film. I know for a fact when I put a skylight-filter to my eye the image is not quite as clear as without, and there's a very slight drop in brightness and change of hue. Surely the film will record this?

I cannot count the number of times I've come to take what I want to be a perfect shot and "um"ed and "err"ed over whether or not that skylight should go, to give the light the simplest possible path to the film for utmost clarity.

Obviously, this is not a consideration issue if you're using a filter for creative effect (say an ND or a poloriser)

What's the general consensus then?

 

[ksmattfish]

I know for a fact when I put a skylight-filter to my eye the image is not quite as clear as without, and there's a very slight drop in brightness and change of hue. Surely the film will record this?

The film is intended to record this. It's a slight warming to counteract the slight cooling caused by shade or electric flash. As far as brightness goes, as long as you are able to compensate with added exposure for the slight (extremely slight) decrease in light striking the film brightness should remain the same in your final images (prints, slides, etc...). If you are just using the skylight filter for protection, and would prefer not to have the pink, then use a UV filter.

I only use UV filters if I anticipate my lenses being in more than a normal amount of danger, and yes there is a minor amount of image degredation, but it is small, so I don't think most folks have to worry about it. I only use skylight filters when I need the added warmth, and since I shoot mostly BW, that's pretty much never. On the other hand, when shooting color I would not hesitate to use a polarizing filter, and that has two pieces of glass to cause defraction

If you experience a noticable reduction in sharpness when using any filter, I'd say toss it and get a better brand. The loss of sharpness due to a decent brand filter is probably less than the loss of sharpness due to hand holding instead of using a tripod.

 

[John Orrell]

Thanks ksmattfish. I can't say I've ever noticed a with/without quality difference because I've never done a test, but I keep thinking about the Hi-Fi philosophy of "the simpler the path, the better the sound" and hence why audiophiles shun tone controls and graphic equalisers (=filters) in order to get the purest sound, and wondered whether the same applied to photography, too.

 

[Hertz van Rental]

The filter thing is just a matter of personal preference. If you use good quality filters you won't notice any degredation of the image except at the extreme limits. But you should use a lens hood. Because the filter is further forward than the lens front element there is a higher risk of lens flare. Flare tends to reduce image contrast so it can cancel out a lot of the effect of a filter.
My preference is to keep to a minimum the layers of glass between image and film - just one less thing to have to keep clean - and only use filters if absolutely necessary. But then I used to work mostly in the studio where you have total control.
But I am a purist at heart. My sound system has an on/off switch and a volume control. ;-)

 

[ksmattfish]

the simpler the path, the better

I would agree that this is a good philosophy to follow. And I also follow Hertz's advice of only using filters when necessary, and I always use a lens hood whether I'm using filters or not. Actually, I've found the lens hood to be even better protection for the lens than a UV filter. It won't stop something going straight in the lens, but does a great job of deflecting rain drops or spilled beer, and acts as a bumper if the lens gets banged into anything.