[BruceBanner]

I'm still researching wide angle lenses for full frame, it seems a lot of the ultra wide ones are not compatible with thread filters, you'd have to invest (heavily) into those square thingy filters (forget the name, lees? whatever...).

I'm currently curious if we're able to do a search for wide angle lenses that can still take regular filters... like... what's the cut off mm before they seem to not manage to have a thread etc?

I mean I know the HD DA 15mm could take filters, I'm curious of an equivalent FoV for FF, that also can take filters...

Anyone care to chime in?

Cheers,

Brucey

[Yamakasi]

irix 15mm takes a 95mm filter

[pinholecam]

The old Soligor/Vivitar 17/4 takes filters, I won't recommend it nowadays as the IQ is not that good.
All the Pentax legacy 20mm takes filters
The Pentax K18/3.5 takes filters, but again, IQ is not worth the trade-off (IMO)

So I think if you want screw on filters on FF and decent IQ, it is 20mm

[kypfer]

My screw-fit Fujinon 19mm f/3.5 takes a 72mm filter

[DeadJohn]

Samyang/Rokinon/Bower wide lenses with threads:

20/1.8. That's the closest FF field of view, compared to the DA 15 on APS-C.

24/1.4 is FF with threads.

The 14/2.8 does *not* have threads. 16/2.0 I think has threads but *not* FF.

[DeadJohn]

Tamron 10-24 has filter threads. It's not sold as FF but is usable in the 15-24 zoom range. The 10-15 range has black corners on FF.

[zjacreman]

The FA 20-35mm F4 takes 58mm filters, and the Tamron 17-35 F2.8-4 takes 77mm filters.

[photoptimist]

The Vivitar Series 1 19-35mm 1:3.5-4.5 takes 77mm filters but only thin ones.

Filters for UWA are really tricky. Polarizing filters work poorly (they make one part of the sky dark and the rest of the sky is light). Filters that lack really good multicoating will lose light in the corners and have have poor contrast.

[77me]

Laowa 15mm f/4 Macro takes 77mm filters.

[gofour3]

The Pentax K18/3.5 takes filters, but again, IQ is not worth the trade-off (IMO)

The K18/3.5 has built-in filters, so no need for screw-in ones. Vignetting could be an issue on FF with screw-in filters.

The KorA15/3.5 also has built-in filters, as well as the older Pentax fish-eye prime lenses. None of these have filter threads.

Phil.

[pres589]

Tokina 17mm f3.5 has threads. I've not used it, it's supposed to be decent, not great.
Tamron 17 SP Adaptall-2 has threads in the hood. They're huge, like 86mm or some nonsense. I do have this lens and the hood/filter thread situation is the only thing I don't like about it.

Sigma and Tamron had some 17-35mm zooms with AF that had filter threads. FF lenses.
Pentax 12-24 has threads, isn't full frame, but works from something like 18mm out to 24mm. Before that you get a black circle on the edges of the image.

All of the Sigma and Tokina 24mm primes from the film days had threads. Sigma Super-Wide II AF had 49mm filter threads. That lens seems to be very good although not built "tough" and sometimes commands silly amounts for the k-mount flavor. The DA 15 Ltd gives a field of view just wider than this lens.

[dms]

The other option is filter gels that fit in a built in gel holder behind the lens. Most types of filters are available as gels (or were)--excepting PL, but that is not as useful w/ ultra wide lens. The Pentax Fish Eye 16 mm f/2.8 and 17mm f/4 have this feature (along w/ built in filters as mentioned above).

[BruceBanner]

Wow... thanks for all the replies etc. Food for thought indeed and lots of lenses to research.

Someone mentioned that with a filter you might get vignetting etc, this has come to be my experience also on certain lenses... perhaps it's time to think about moving onto those square system filters?

Ok... so if then considering dumping all screw in type filters and go with the square systems, how does it work... i mean what options do we Pentaxians have? How do they install onto the lens/camera? What brands are recommended etc (cost vs quality etc).

I may make a separate thread about this but I'll see how the response goes for this, if as good as before then definitely no need

[DeadJohn]

The lens search tool might find additional options for threaded filters. Here's a saved search for 2mm or larger filter threads (the tool usually defaults to no threads or larger). <= 24mm Third Party Lenses | PentaxForums.com

[northcoastgreg]

Ok... so if then considering dumping all screw in type filters and go with the square systems, how does it work... i mean what options do we Pentaxians have?

When it comes to square filters, Pentaxians have just as much options as anyone else. You will need a filter holder, an "adapter" to attach the filter holder to the lens, and then the filters. There are different size square filter systems available, the most common being 85mm, 100mm, and 150mm. Larger filters obviously require larger filter holders, and the price goes up accordingly.

For wide angle work, you're probably going to have to go at least to 100mm filters — and that's assuming the wide-angle glass you are using has filter rings. For a lens like the DFA 15-30, you have no choice but to go with 150mm filters, which are large and expensive ($150+, and that includes uncoated resin filters). If you bought a complete set of high-quality square filters for the DFA 15-30 along with the holder, you easily spend more money than the DFA 15-30 costs.

I use 85mm and 100mm square filters, but only for graduated neutral density filters. For everything else, I use screw-in filters. That's true even with my wide angle lenses (i.e., DA 15, DA 12-24, FA 20-35). The problem with the square filters is that many of them aren't even glass (they're optical resin) and, whether glass or resin, many of them don't seem to be multi-coated (or even single coated for that matter), and I prefer using multi-coated filters whenever possible. Generally speaking, all I really need in terms of screw-in filters is a high-quality polarizer and a nine or ten stop ND filter.

The one advantage of a square filter system is you only have to buy one set, but if you're getting 100mm or 150mm filters, that will be a bit cumbersome to carry wherever you go and to use on the lens. Screw-in filters are much more compact and preferable, IMO, for that reason alone.