Sigma makes the 18-125mm and Pentax a 18-250mm (a rebadged Tamron). At first I was very sceptical about the DA18-250mm but 3 weeks ago I bought one and have not been disappointed. It is quite sharp, but be prepared for some vignetting which can be photoshopped away.

Pentax makes lenses marketed under two names:

1. Pentax
2. Schneider Kreuznach

All lenses are assembled in Vietnam, also the ones with the Schneider Kreuznach label on them, as I have seen on the Schneider 18-55mm.

The question is whether Pentax designs its own lenses. The following interview gives reasons to believe that Pentax lenses are designed by Schneider Kreuznach. The interview is in German and the translation is made by Babelfish which is quite bad at times:

In as far one can actually still trust Schneider-Kreuznach after (good) the name, as far as it concerns Schneider-Kreuznach lenses into digital cameras from Kodak and Samsung? The short answer reads: "Schneider-Kreuznach is on it only , where also Schneider is in it", the detailed answer gives Peter Lebeda, Leiter Public relation/Communication with Schneider-Kreuznach after, in an interview with photoscala:

What at the Schneider-Kreuznach lenses in the digital cameras of Samsung and Kodak is actual Schneider-Kreuznach, which of it pure marketing with the good name?

Schneider-Kreuznach together the camera concept develops with Samsung and/or Kodak. In the concrete conversion phase is responsible Schneider-Kreuznach for the development of the lenses. It applies thus the principle: "Schneider-Kreuznach is on it only , where also Schneider in it is". The name Schneider-Kreuznach stands for quality. It guaranteed as quality seal with the digital cameras of Samsung and Kodak those world-wide well-known Schneider-Kreuznach quality. Concerns a co-operation in the actual sense of the word, put on as co-operation of two partners - and evenly not around buying a lizence from Schneider-Kreuznach after to the enterprises of the photo and/or electronics industry.

To what extent can one trust in the quality of Schneider-Kreuznach lenses?

The development and the tests with self-developed measuring technique correspond to the high quality criteria, Schneider-Kreuznach also within the professional High end range put on and are on the at present most modern state of the art.

Are the two new Samsung lenses to the DSLR models of Samsung own developments of Schneider-Kreuznach? And/or from where does the remarkable similarity come to the appropriate Pentax lenses?

All of the partners used Schneider-Kreuznach lenses are "Schneider-Kreuznach lenses". The camera concept gives the Design of the camera and concomitantly the Schneider-Kreuznach lenses. I.e. a Schneider-Kreuznach lens in a Samsung camera looks differently than e.g. a Schneider-Kreuznach objective in a Kodak or a roll egg camera. In the concrete case of the change objectives to the DSLR models of Samsung series production runs under Samsung direction. Schneider-Kreuznach is responsible for the development of the lenses, the tests of the prototypes and examining the objectives from series production. The interview led Thomas Maschke for photoscala. We thank the Jos. Schneider optical works GmbH, in the special one our interview partner Peter Lebeda, for the answer of the questions.

http://www.photoscala.de/node/1730

Yesterday I had a Samsung DSLR in my hands. It was fitted with a 18-55mm Schneider Kreuznach lens, assembled in Vietnam.

We can safely assume that Pentax manufactures lenses under the name of:

1. Pentax
2. Schneider Kreuznach.

John Riley mentioned it in his opening post and I posted it at DPR. Nobody seems to have noticed this sentence (a Babelfish translation):

"In the concrete case of the lenses to the DSLR models of Samsung series production runs under Samsung direction. Schneider Kreuznach is responsible for the development of the lenses, the tests of the prototypes and examining the kenses from series production."

http://www.photoscala.de/node/1730

Roland Mabo seems to know a lot and he rejects this idea.

Personally, I don't care who designed the lenses, as long as they are good. Now I understand why some people say that the abbreviation DPR stands for DePressing Review.

If you could read German, we would not need Babelfish

I found an interesting article in which the spokesman says that Schneider lenses can only be called Schneider lenses if they have been designed by Schneider Kreuznach. That can mean two things:

1. The Pentax lenses have been designed by Schneider if the Schneider lenses marketed by Samsung are the same as Pentax lenses.

2. The Schneider lenses by Samsung are not of the same design as the Pentax lenses.

Here is a Babelfish translation:
To what extent can one actually still trust cutter cross after (good) the name, as far as it concerns cutter cross postobjectives into digital cameras from Kodak and Samsung? The short answer reads: "cutter stands only drauf, where also cutter is in it", the detailed answer gives Peter Lebeda, Leiter Public relation/Communication with cutter cross after, in an interview with photoscala: What at the cutter cross postobjectives in the digital cameras of Samsung and Kodak is actual cross after cutter, which of it pure marketing with the good name? Cross after cutter together the camera concept develops with Samsung and/or Kodak. In the concrete conversion phase is responsible cross after to cutter for the development of the objectives. It applies thus the principle: "cutter stands only drauf, where also cutter in it is". The name cross after cutter stands for quality. It guaranteed as quality seal with the digital cameras of Samsung and Kodak those world-wide well-known cutter quality. Concerns a co-operation in the actual sense of the word, put on as co-operation of two partners - and evenly not around a lizenzvergabe of cutter cross after to the enterprises of the photo and/or electronics industry. To what extent can one trust in the quality of cutter cross postobjectives? The development and the tests with self-developed measuring technique correspond to the high quality criteria, cross after cutter also within the professional High end range put on and are on the at present most modern state of the art. Are the two new Samsung Wechselobjektive to the DSLR models of Samsung own developments of cutter cross after? And/or from where does the remarkable similarity come to the appropriate Pentax objectives? All of the partners used cutter objectives are "cutter objectives". The camera concept gives the Design of the camera and concomitantly the cutter objective. I.e. a cutter objective in a Samsung camera looks differently than e.g. a cutter objective in a Kodak or a roll egg camera. In the concrete case of the change objectives to the DSLR models of Samsung series production runs under Samsung direction. Cross after cutter is responsible for the development of the objectives, the tests of the prototypes and examining the objectives from series production.

http://www.photoscala.de/node/1730

I agree with your last statement. But from what I have read I am quite convinced that Schneider Kreuznach did the lens designs and Tokina and Pentax each manufactured the actual lenses in their own factories. The speed with which Pentax came with the DA lenses was amazing. Pentax was the last camera brand to jump into the DSLR market and had to set up a system.

The Samsung lenses are not called so, they are called Schneider Kreuznach:

Schneider AF D-Xenogon 2,0/35 Pentax/Samsung
Schneider AF D-Xenon 2,8/100 MakroPentax/Samsung
Schneider AF D-Xenon 3,5-5,6/18-55Pentax/Samsung
Schneider AF D-Xenon 4,0-5,6/50-200 Pentax/Samsung
Schneider AF D-Xenon 4,0/12-24 Pentax/Samsung

The DA16-45mm is called Samsung AF 4,0/16-45 Pentax/Samsung

We can safely assume that Pentax lenses are also named Schneider Kreuznach. Whether the lenses were designed by Schneider Kreuznach of by Pentax, I don't care. They are good lenses.

BTW: If you even come to Bad Kreuznach it is a lovely place to use your Pentax lenses. You will take many lovely pictures.

Samsung uses high-performance lenses from Schneider-Kreuznach in many of their digital camera models: zoom lenses the D-Xenon and D-Xenogon range for the GX SLR cameras from Samsung:

This advertising page is quite clear, all the D-Xenon and D-Xenogon lenses are from Schneider Kreuznach.

There are some mistakes in English. The German "von" has been translated in English by "from". The German preposition "von" clearly indicates "made by". The correct English prepositon is by.

I understand from this advertising page that the Samsung lenses have been designed by Schneider Kreuznach. They actually bear that name. When I put one and one together (just guesswork): The Samsung GX10 and the older models GX-1L and GX-1S were in fact Pentax cameras. Samsung had the lens designs for the lenses. And Samsung/Schneider Kreuznach licenced Pentax to produce the lenses:

"Cooperation for the benefit of end users: Schneider-Kreuznach has been cooperating closely with the Samsung technology group since 1995, thereby making Schneider professional lens systems accessible to hobby and amateur photographers."

http://www.schneiderkreuznach.com/samsung/index_e.htm

http://www.schneiderkreuznach.com/samsung/objektive_samsung_e.htm

The link in English.

A translation by Babelfish:

Also the best camera is only as good as their objective - applies to modern digitalcompact just like for semiprofessionelle mirror reflex cameras with highly soluble image sensors. For this reason Samsung begins in many digital camera models high-performance lenses of cutter cross after. DSLR and compact objectives of the record-suspicious Varioplan Ultrazoom in the semiprofessionellen Samsung Pro815 with an smallpicture-equivalent focal length range of 28 - 420 mm, over the highly soluble mini zoom shots of the Samsung NV Kompaktserie up to the exquisiten fixed focal lengths and zoom shots of the D-xenon and D-Xenogon-row for the GX Spiegelreflex cameras of Samsung: Cutter cross after vouches here as quality seal for best imaging capacities. With the development of modern zooms the decades of experience come to carrying, which are based among other things on the world-famous Variogon series. The more focal lengths in an objective to be united must, becomes the more aufwaendiger the correction of optical remaining errors. The employment of specialized computational programs on ultramodern computers and the know-how of cutter engineers vouch even with extreme zoom shot ranges and high-bright constructions always for optical completion. Also the cutter precision objectives consider to the circumstance that with the introduction of the digital photography the claims of quality rose to the optics of a camera enormously. A central meaning for new, still years ago inconceivable objective constructions like ultrakompakte cutter superzoom shot 2.8 - 4.0/28 - 270 mm in the Samsung NV7 OPS plays in the meantime the Asphaerentechnologie. Aspheric elements, how they are used in many cutter optics for Samsung, raise the leistungsniveau of a compact or a change objective clearly and permit bright, compact building methods without reductions with the image quality.