Wratten Gel, Acrylic, or Glass Filters?

[Kirk Gittings]

I first heard about this from Fred Picker in his newsletter I believe. It worked just fine but was a PITA as I said above.

[MartinP]

Thanks for the speedy responses! I think making myself a super-effective lens-hood will be the way to go, unless it is both sunny and windy - which is certainly possible here, together with hail and rain, sighhhhh.

Edit: Here is the clip that sparked off the idea, at about two minutes Mr.Butcher mentions filters. My 4x5" camera is a baseboard design, made from foamboard and spruce strips, currently being fiddled with to make a sprung-back instead of using rubber-bands. It should be possible to add to the front box section to make a significant lens-hood and filter-holder (or find the right thread-adapter).

[Drew Wiley]

I sure hope you didn't believe everything Fred Picker said, Kirk. For one thing, every single lens maker and reputable filter manufacturer discourages rear filters for valid optical reasons. Second, do a side by side test, front versus rear filter application, then check the results with a loupe or serious enlargement. It becomes pretty apparent why. A few huge telephotos as well as process lenses were designed for internal filter insertion, near the nodal point. Otherwise, it's always in front.

[Jerry Bodine]

Apparently Sinar has no problem with using filters behind the lens. They offer a filter holder #547.41 that is attached to their Behind-The-Lens shutter and holds up to three 100mm (4") filters - presumably gels.

[IanG]

I think it's something you have to try for yourself. I've used Glass filters, gels, acrylic filters etc, over the years and been critically happy with them all. The tests I've seen references to are how effective different UV filters are which quite frankly is gear porn.

Given a choice logic is a good glass filter is the best but with various LF lenses with various filter threads that's not very practical, I;ve used Cokin & laterLee filters for years, I think since Cokin were first available in the UK about 40 years ago. I've never had an issue even with 35mm where nany problem would be far more apparent, I've also never heard of a single image quality issue. I have heard of slight colour shifts with ND filters but then I've seen the same posted here for high end glass ND Center filters.

The reality is if you look at some of the people using Cokin & Lee acrylic/resin filters they are known for the exceptionally high quality of their LF (now mostly likely digital) colour images.

As Dan Fromm says about lenses, ask it yourself, try it, see what it does and the same goes for filters.

Ian

[Drew Wiley]

Of course, everyone has a right to learn the hard way. It's just time and money.

[Kirk Gittings]

I sure hope you didn't believe everything Fred Picker said, Kirk.

What a laugh. If I did I'd still be doing it! Of course I don't believe everything anyone says. If I used to, listening to you would certainly have cured me of that pretty quick!

Here is what QT says:

"Attaching filters at the rear of the lens

With LF, you have the option to attach filters at the rear of the lens. This works for color correction filters which don't need to be adjusted. The advantage is that a filter inside the camera is less likely to get dust, dirt, smudges, fingerprints, and will cause less flare.
There are two precautions to take:

You have to be super careful to keep your filter clean. Any dust, dirt, smudges, fingerprints, as well as defects, will have more of a detrimental effect on the quality of the image as the light passing through the imperfections has already passed through the lens.
A filter mounted behind the lens creates a focus shift equal to 1/3rd the thickness of the filter so all focusing must be done with the filter in place, except for gels, whose thickness is neglectible."

[eli]

Kodak made small, thin metal frames for the Wratten filters and I simply leave them on the filters, kept in their envelopes, which makes them easier to handle and less likely to blow away.
If you like, you can also cut these filters to size for using with series filter holders, push on and threaded.
You also might consider giving the Series glass filters a try as well. There were a lot of good makers of the filters and I don't see a lot of folks using them, meaning you likely won't have to spend a bundle on them, when you find them.

[IanG]

Of course, everyone has a right to learn the hard way. It's just time and money.

What planet are you on ? There's nothing hard to learn, you need a reality check.

In practice we sometimes have to use gel filters, in theory these should be the worst option compared to resin/acrylic and then glass, but they don't affect image quality used carefully in fact they are usually used to improve it.

In 50+ years of shooting film I've never had an image degraded or losing any quality because a filter of any type gel, acrylic/resin or glass has been used.

Ian