That about sums it upOriginally Posted by LabRat
That about sums it up
Manufacturers DON'T lie about filter factors! - certainly not in my experience. What they are necessarily doing is providing GENERIC recommendations based on their own specific films and what a particular filter designation does. Even allegedly matched filters can vary somewhat between manufacturer to manufacturer. Filter sometime fade.
Specific films differ somewhat with respect to precise spectral sensitivity, even within the same overall Panchromatic designation. This all means that one need to run an actual test to find his own ideal filter factor in each case, but it will generally be close to the published value. And once you've arrived at this, it will be a more accurate method of adjusting exposure, using these filter factors, then reading with a meter through a filter, because meters have their own spectral sensitivity which is not likely to be the same as the film itself. TTL metering in small camera can be even more deceptive. In my own work in the field, I just apply the appropriate filter factor and am done with it. Seems to work every single time for me.
Drew,
I know, I know... Hence the smiley face. It's something I tell my students all the time after they figure out that I've simplified something in order to give them a basic understanding. I say "I lied..." tongue firmly in cheek, "... and now on to the next level."
Many just see a filter factor and take that as gospel; they don't know that it's generic information or anything about how to go about testing and compensating.
Certainly, you must admit, that information regarding filter factors has become even more generic over the years. I miss the tungsten and film-specific factors manufacturers used to publish.
Best,
Doremus
Thanks for clarifying that. Some tech sheets give both daylight as well as tungsten factors, but both of them are just starting points. A wasted roll of cheap 120 film shooting gray card bracketed exposures with any unfamiliar new filter is time and money well spent before moving on.
May as well add that ISO as well as guide numbers are also starting points.
Well, you can add that, Bob. I've never used a guide number in my life. My older brother was taught to do that in commercial Photo School. I never use flash.
You guys are amazing. Thank you all for the help. Now I have half a plan. I know exactly what color filters I want to start with Yellow and orange. My only lens is a Fuji W 150mm which (I think) uses 55mm filters. I'd like to get a 90mm next and I'm pretty sure is will NOT have a 55mm thread. Then after that I'd like to go with a 300mm and again, pretty sure it wont have 55mm threads.
So, in your experience, is it better to go with circular threaded filters and use reducers OR use the square shape filter holders OR is it all 6 of one, half dozen of another? I'm leaning towards the square shaped ones, because I'm pretty certain they will work on any lens. Just seems to be a good way to go. But I'm kinda clueless. That's why I'm here.
Thanks!!
Adam
Do some research and figure out the filter threads of the lenses you might get. Then get filters in the biggest size, and use step-up rings on the other lenses. I prefer the quality of multi-coated, glass, round filters. Resin/gelatin filters might be ok at first, but in my experience they soon become scratched just from taking them out of their envelopes.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
I exclusively use multicoated round thread-on glass filters in the field, or single-coated if it's the only option in a particular tint I need yet still high quality. They last longer than other options, are easier to clean, attract less dirt, less reflections, better scratch-resistance etc. Various brands: Hoya, B&W, Heliopan, Singh-Ray, a few Tiffens.
You’re likely going to get many answers based on preferences... so here’s my 2c:
If you ever go into grad filters you’ll need a holder, as you can’t do that with a screw in filter. It’s safe to assume that a 100mm filter system will be sufficient for 90% of the lenses out there. So you can get color resin filters that are cheap or more expensive glass ones. You can add a polarizer, NDs, warming, grad filter, etc.... as you build your collection, and all you need are adapter rings to convert from any size lens filter ring to the holder size. Typically adapters for 52, 67, 72 and 77 mm is all you will need. NISI, Hitech, Breakthrough, Lee, etc are good brands for film holders.
You can definitely go the screw in route and buy the largest size ones, and worry that if you stack filters (color+polarizer or color+ND+polarizer) you may get vignetting— rectangular filters don’t typically have that issue. This may or may not be an issue depending on your type of photography.
Of course it’s also a question of upfront investment, with a single lens buying 2 screw in filters it’s cheap. You can decide later if/what route to follow.
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