Pentax lenses vs. Sigma lenses

[arctic corsair]

Hi

 

I am currently using a Samsung GX-1L with a pair of the kit lenses (18-55 &

50-200). I am looking to adding a wide angle lens to camera kit.

My local store has recommended the Sigma 10-20mm for use with this kit. What

sort of quality is the Sigma compared to the Pentax?

 

 

Also i'm looking at getting into macro and have seen lenses at 105mm. Again

how do the Sigma's compare as against the Pentax? Is 105mm a good focal for

first time macro or would a 50mm be better? Can I use macro lenses for normal

shots as well or do they suffer at the infinity end of the focusing for the macro?

 

 

Finally, I do a lot of shipping photography and a large lens is often needed to

pull in the shot over a distance. I have been having some good results with

an ancient Paragon 300mm. I'd like to be able replace this with a more modern

AF lens. Sigma have a 135-400mm that is reasonably priced. How does this

lens perform? I would only be using this lens at it's extreme on occasions

(2/3 times a month) so I don't want to be paying out ???? for a lens that i'm

not going get value for money from.

 

 

Many thanks for the help.

Mick

[h._p.]

I can't help you with the 10~20 or 135~400 lenses but I would say I've always been pleased with the Sigma lenses I've had.

 

A longer focal length is easier to use for macro than a shorter one - I use a 90mm Vivitar myself. Both the Vivitar and a 50mm Nikkor Macro that I've used work extremely well at normal to infinity.<div></div>

[arctic corsair]

I should also add that I would like to have a go at some astrophotography some time hence the long focal length.

[Jochen_S]

I haven't got no WA zoom. A few threads further down somebody claims both to be of the same quality and somebody else says Sigma wasn't available for Pentax.

 

Macro: Pentax is really good. I have the older FA 100mm f2.8 and believe it might be my best lens by far. I got it as "the workhorse" so the superior mechanical quality of Pentax was a issue for me and the whole purchase a no nonsense case. I own a older 50mm F macro too. It causes internal reflections when stopped down entirely, so it's a compromise, especially without a focus limiter, but at ordinary apertures it performs good. - If you need a macro lens for close up work get the longer one. There's hardly a chance to place some light between a 50mm and really small stuff. You'll be way too close to portrait a hamster and you'll intimidate the coolest insects. The shy ones will make you wish to have a Tamron 180mm anyhow. Add a 50mm later when you need it, for which reason ever, I just wanted a wider studio killer lens for bigger small products.

 

My old 14mm f3.5 FF&MF Sigma prime is dissapointing enough to make me drool over the new Pentax DA, that I'll surely buy sooner or later.

 

Last general advice of somebody comparably dissapointed by all of his zooms: Get a really good prime. Have your socks nocked off, recalibrate your demands and shop accordingly.

 

I didn't seriously shop for a long lens yet. Usually I just grab the 135mm f2.8 F. Occasionally I use a IMHO crappy Sigma 70-300 APO macro, surely not the latest model but dirt cheap on ebay. Besides the low optical performance the screwdriver AF is really challenged with that focal length; it takes ages to lock on a aproaching jogger or similar. I will not buy anything reasonable as long as I have no K10D to use ultrasonic focusing motors in such lenses.

[stemked]

I can only speak to film lenses so this may not be terribly helpful.

 

The Pentax 100mm FA/F f2.8 actually didn't perform quite as well as the Sigma 105 mm f2.8 at 2.8 (tests conducted by Practical Photography back in the 1990's) but Pentax outperforms the Sigma at all other F stops. Therefore if it is macro you are after where you normally stop the lens down Pentax is the better choice. However it really is hard to find a poor optic in a macro. Even the cheap-O Corsica/Phenix/Pentax 100mm f3.5 is a great optic stopped down.

 

The Pentax FA/F 100mm f2.8 has a limitor that is a nice feature.

 

Yes, I know there is a new 100mm Pentax macro that weighs a lot less. But I don't know anything about it.

[jeff_drew4]

I don't use DSLRs yet but DO use the Sigma 135mm~400mm APO zoom on my Pentaxes. Considering the price tag, it is an excellent buy and reasonable compromise. When properly mounted and carefully used it provides excellent results. It's quick to use and decently made. Compared to some Pentax zooms, it's at least AS GOOD AS many, but not as good as a few models, like the 80~200 f/2.8 etc. I've always considered zoom lenses for their convenience and are usually a compromise at some level. For light duty usage, it's a fine candidate. FWIW: I prefer to use older, non-AF, bodies and fixed focal length lenses for my astrophotography. The Sigma teles are okay, but definitely not ED-flourite type caliber astronomy lenses. Many zooms add considerable weight and are slower, but can be used for astrophotography.

[mountainvisions]

The Sigma 10-20 is a dog.

 

Don't buy it if image quality is your only requirement.

 

Look at the Pentax 12-24 f/4 or if Tokina is making a 12-24 f/4 in the pentax mount (i've heard they don't). The pentax and the tokina are possibly the same lens.

 

The Tokina is a top flight lens with excellent flare control.

 

The Sigma shows a lot of distortion, isn't as sharp, and doesn't have great flare control.

[vuk_vuksanovic]

mick.

<br><br>

first of all, almost all zoom lenses are terrible compromises and you should stay away from them. pentax has made some very nice primes (such as the SMC 50mm f/1.4) that you can pick up for peanuts these days. the newer, limited series is also quite outstanding, but pricier. unfortunately, with wide-angle glass, you have to spend a tidy sum to get decent results and matters are complictaed by the DSLR crop factor which means you need to get something more extreme (and thereby expensive) than you would with a full-frame camera.

<br><br>

as for macro, the tamron 90mm f/2.5 is a very good lens and quite affordable, although the bokeh may let you down in certain situations. i do find it a bit long on my istDS2, but a 50mm alternative would be too short for me. btw--on a recent outing, i was "stuck" with only this lens in the bag and here are the results: <a href='http://vukfoto.com/swann/'>http://vukfoto.com/swann/</a>

[andrew robertson]

Modern zoom lenses can be superb. Quality is no reason to stay away from them. The

reason to stay away from them is that they are slow and expensive compared to prime

lenses.

 

I would get anything other than the 10-20mm. Your friendly camera store wants to sell

you that Sigma because that's what they make the highest margins on.

 

I think your best bet is to get an older, used Pentax prime lens like a 300 or 400, which

will spank the zoom. It'll be cheaper, too.

[mountainvisions]

Here's the problem some of the post on here are limiting the lenses to a grouping by brand or type.

 

The bottom line is pentax makes dogs, sigma makes dogs, tokina, nikon, canon, ect.

 

And all make some great lenses.

 

The 10-20mm is not a good lens by both user reviews, sample images and lab test. It's selling point is the 10mm wide end.

 

The 12-24 while not as sharp as primes at most lengths is a stellar lens. With excellent flare control (something tough in a wide angle zoom or even wide angle prime).

 

The sigma 105 is a stellar lens, btw. So is the Tamron 90mm 2.5/2.8

 

The sigma 100-300 f/4 is a very very good lens with a reasonably fast fixed aperture. On the APS-C sensors it yields a 450mm f/4. That was my next lens till the SSM mount came out, now I will have to wait to see how long the SSM lenses take to hit the market. Hopefully by June Sigma will have the 100-300 f4 in a SSM mount.

[mawz]

The Sigma 10-20mm is decent, and very wide. The Pentax 12-24 (which is the Tokina design, modified by Pentax) is much better, although you lose some wide (15mm equivalent vs 18).

 

The Sigma 105mm macro is quite good, but there is little price difference between it and the Pentax D-FA 100mm and the latter is a superb lens.

 

I'd look at the Sigma 100-300 f4 over the 135-400. the former is an excellent lens.

[arctic corsair]

Thanks for the replies fellas.

 

I guess the Sigma 10-20mm wide angle lens is one to stay away from then. For the relatively small difference in price I guess i'll go for the Pentax one instead. Same with the 105mm. It seems that the Pentax branded lenses are a much better lens than the Sigma equivalents.

 

With reference to zooms. When I got back into photography earlier this year with an old but very capable Pentax P30 I moved away from using zooms and took a liking to some SMC primes. They were the SMC-M 50/2.0 and the SMC-M 28/2.8 along with a Vivitar 135/3.5. I produced some great results with those lenses despite their age and low cost. Since getting my dSLR I have found myself back using kit zooms for some reason and if i'm totally honest i'm not 100% happy with the results.

 

I've just replaced that Vivitar 135 with another SMC-M to match my others so i'll give it a shot on the dSLR when it arrives. I really need to take the bull by the horns so to speak and leave the zooms at home.

[dogbert]

I use the sigma 10-20 on a Canon. I assume the Pentax version is the same design. I am not sure why it is refered to as a dog here. My copy is very good and compares very well with most of my other lenses (of which I have quite a few). It is a bit below my primes wide open, but at f5.6 it pretty much compares with them and is as good, if not better than any of my Canon and sigma zooms.

 

It seems often a lenses reputation is established by one or two dissatisfied users with everyone else just repeating the same old story without checking for themselevs.

[paul_au_yeung]

I have a Sigma 10-20mm on my K100D and I love it. In terms of macro, I have tried both Sigma 105mm and Tamron 90mm. I decided to go for the Tamron because of its superior quality. The Sigma is good but just not as good as the Tamron.