[Ed Hurst]

Hello all,

I am a long-time Pentax user (albeit medium format) and am very interested in the K1. Does anyone know of fast, rectilinear super wides that can be used with the body? I'm getting rather confused about which lenses are actually full frame compatible. Ideally, I'd like something in the 14mm to 19mm range, faster than f2.8. But interested in knowing the best options. Am open to third party options as well provided the quality is good.

Many thanks,

Ed

[Na Horuk]

, I'd like something in the 14mm to 19mm range, faster than f2.8.

Ultra wide, faster than f2.8, and FF? That is aiming high. Practically doesn't exist. Sigma's 24-35mm f2 is the only lens I can think of, and its not made in K-mount (at least, not yet. Feel free to encourage Sigma to do it). Pentax' DFA 15-30mm f2.8 is the closest that Pentax gets to your criteria, and is reportedly a pretty great lens.
The Sigma 18-35mm f1.8 is not FF; it has heavy vignetting and does not cover the edges on the wider end. It is made for K-mount, though

Samyang 14mm f2.8 is your next best bet. It has A an aperture ring, but no AF. Good lens, sharp, but does not have filter threads. Just make sure you get a good copy, without decentering, and you should be fine. Very affordable, too.

are actually full frame compatible

All DFA, FA, F and older lenses are FF compatible. Many DA lenses are FF compatible - there are some threads about this already. Feel free to search "DA lenses on FF" or similar keywords. However, with DA lenses, Pentax does not guarantee that the edges will be top quality, or even useable (particularly zoom lenses sometimes fade out to completely black edges on FF, as they only cover ASPC frame)
Sigma has some other designations (DX, DG??), but I don't really know much about those, so double check.
Samyang 14mm, 24mm, 35mm, 50mm, 85mm, 100mm are FF compatible, as far as I know. Samyang 8mm, 10mm, 16mm are not.

[D1N0]

There is the Irix 15mm F2.4.

[Kerrowdown]

Fast rectilinear super wides for K1

On the super wides... lens speed has never been an issue for me.

I've used my “Mistress" (SMC Pentax-A 15mm F3.5) and over the years she has produced some fine imagery for me.

https://www.pentaxforums.com/forums/12-post-your-photos/320734-architecture-shes-wide.html

[Paul the Sunman]

The Irix does look interesting. MF but AE, front filter mount (95mm!), and fully weather sealed (for the Blackstone version).

Pentax does have a "Large Aperture Ultra Wide-Angle Single Focus" lens on its roadmap for "2017 or later".

[Kozlok]

Why not just use the FA31 and stitch a big pano in post? 75% of the time, that should work where you want UW anyway.

Sigma makes the 24mm/1.8 that is FF, and a bit wider than the 31. And there's the Pentax FA*24mm as well.

[Winder]

Hello all,

I am a long-time Pentax user (albeit medium format) and am very interested in the K1. Does anyone know of fast, rectilinear super wides that can be used with the body? I'm getting rather confused about which lenses are actually full frame compatible. Ideally, I'd like something in the 14mm to 19mm range, faster than f2.8. But interested in knowing the best options. Am open to third party options as well provided the quality is good.

Many thanks,

Ed

A new ultra-wide is on the road-map for next year. Right now the 15-30mm F/2.8 is your best option.

[pathdoc]

Why not just use the FA31 and stitch a big pano in post? 75% of the time, that should work where you want UW anyway.

Sigma makes the 24mm/1.8 that is FF, and a bit wider than the 31. And there's the Pentax FA*24mm as well.

Depending on what the OP is shooting, pano-stitching may not work (e.g. moving subjects).

[zzeitg]

14-19mm? Well, what about 20mm?


There was Sigma 20mm f1.8. Still you can find it on eBay from time to time. Sigma 20mm F1.8 EX Aspherical DG DF RF Lens Reviews - Sigma Lenses - Pentax Lens Review Database


Here's flickr pool. Not a bad lens at all! Just my 2¢.
https://www.flickr.com/groups/sigma20mmf18/pool/

[stevebrot]

This subject has come up every couple of weeks since the K-1 was announced and by extension (legacy lenses in the range 15mm to 24mm for usable on APS-C) ever since I joined the forum in 2007. Ultra wide rectilinear SLR lenses for 35mm (FF) format have never been particularly common, fast options much less so (almost nonexistent), and high optical performance (low distortion, flat field, sharp, low CA, etc.) even more rare.

The answer to the OP's question for current product may be answered with a simple filtered search on the B&H Web site.

SLR Lenses, DSLR Lenses | B&H Photo Video

Skimming through the list, the Samyang 24/1.4 is the only current production prime that almost meets the basic criteria with the Pentax D FA 15-30/2.8 being the only zoom that even comes close. The Samyang 14/2.8 comes close too. IMHO, the best lens on the list is the Sigma 15/2.8 fisheye...outstanding performer.

As for legacy glass: Pentax FA* 24/1.8 24/2

I am dying to know...What is the use case for such a lens? Nights at the skate parK?


Steve

[WPRESTO]

There is the Irix 15mm F2.4.

SKAIK The Irix is not yet available in any mount, and the only word on IQ is from the manufacturer, but, they seem to think it is really, really good.

[RGlasel]

I am dying to know...What is the use case for such a lens? Nights at the skate parK?

Subject isolation through shallow DOF in UWA portraits? It's the tyranny of the photography by number zealots; what is observable in the photograph with the naked eye in whatever medium it will be realistically viewed on is irrelevant, what really matters is keeping ISO at 100, shutter speed at 1/1000 second and DOF so shallow not a single object in the frame is entirely in focus. That way the photographer can never be accused of recording motion blur or generating noise artifacts or masking less than perfectly precise focus. It's like the reincarnation of the Inquisition.

[Sagitta]

Theres also nothing stopping you from using an APS-C zoom lens on the FF. When I first caught wind of the K-1 coming down teh pike, I slapped my Sigma 10-20mm onto an old body to see where and if the vignetting would cease to be an issue, and it looks (at least through the viewfinder) to be around 14mm. Sure, I'm losing half the lens's range, but I'll take 14mm on a full frame any day of the week.

[Auzzie-Phoenix]

Doesn't Laowa have a lens that fits into this category?

[willeisner]

I quite like my K 15mm Al, I think it would be a great legacy option.