Sigma 30 f1.4 vs 10-20 f4-5.6

[PhoenixEnigma]

I'm going up to the lake in about a week and a half. Before I go, I'm finally picking up another lens (as I promised myself I would with my tax return). My options are a Sigma* 30mm f/1.4 or a Sigma 10-20mm f/4-5.6. I already own a 16-45mm f/4, 18-55mm f/3.5-5.6, 50mm f/2 (MF only), 50-200mm f/4-5.6, and 350mm f/5.6 (MF only). I shoot a lot of landscapes, a little sports, and a little nature, and I'd like to shoot more portraits but I'm not sure that will actually happen.

Price is pretty much a wash once filters are accounted for.

Any advice or opinions on which way I should go?

*Pentax leaves first party options a little thin

 

[VulgarDisplay]

I'd go with the 30mm prime. No point getting another zoom that doesn't off a better aperture, and probably only marginal IQ improvement over the 16-45mm you already have. Unless you want that super wide 10mm ability of the second lens.

 

[Gooberlx2]

From what I've read, the 30mm is super sharp in the center, but gets real soft real quick as you move out. However, that may not be an issue for you (assuming could be QA variance), or could even be a benefit if you like to isolate center subjects.

I bought the Pentax 35mm 2.4, which is a fabulous lens for the price. Sometimes wish I had that wider aperture though.

 

[yhelothar]

Personally, I'd get the 10-20.
Ultra wide is awesome for landscapes.

30mm isn't quite wide enough for landscapes on an APS sensor and the 50/2 can cover low light.

 

[iGas]

Get the 10-20mm because you are into landscape, and if you have the need for a new lens.

And get rid of the 16-45mm since you already own the 18-55mm.

 

[Gooberlx2]

Get the 10-20mm because you are into landscape, and if you have the need for a new lens.

And get rid of the 16-45mm since you already own the 18-55mm.

I think the 16-45 is either a limited or star lens, either line of which should be vastly superior to the 18-55 kit lens.

edit: nope, I'm wrong, just a fixed aperture DA lens. Still, I would expect the optics on the $600 lens to be superior.

 

[PhoenixEnigma]

Get the 10-20mm because you are into landscape, and if you have the need for a new lens.

And get rid of the 16-45mm since you already own the 18-55mm.

I'm leaning towards the 10-20mm, I think, because I know it's a lens I'll get a good deal of use out of (I'm often at the wide end of the 16-45mm), whereas the 30mm would be useful only if I really start shooting more portraits (as I've got the 30mm focal length covered by zooms, and the 16-45mm is quite a sharp lens).

Odds are in the long run I'll end up with both of them, though

As for ditching the 16-45mm in favour of the 18-55mm? Not a chance. It's a much better lens, if a little shorter on the long end, and a good walkaround lens. The kit lens is only really good when I'm worried about damaging a lens for some reason.

 

[SecurityTheatre]

30mm is not so great for portraits. It's not terrible, but generally people call it a "portrait" lens around the 85mm "equivalent", which means about a 50mm or 60mm for you.

It's certainly not a bad lens, I used to have one on my D2X quite often, but you will get more use out of the super wide.

I'll also second the call to sell one of your mid-range zooms. Having overlap like that just robs you of cash and makes it hard to choose which to use.

Sell the 18-55 and use the money to get a 50mm 1.8 (or 1.7 for Sigma) for the money. This gives you some of the low-light capability of the 30mm along with "portrait" capability.

Then you can do both!

 

[iGas]

I'm leaning towards the 10-20mm, I think, because I know it's a lens I'll get a good deal of use out of (I'm often at the wide end of the 16-45mm), whereas the 30mm would be useful only if I really start shooting more portraits (as I've got the 30mm focal length covered by zooms, and the 16-45mm is quite a sharp lens).

Odds are in the long run I'll end up with both of them, though

As for ditching the 16-45mm in favour of the 18-55mm? Not a chance. It's a much better lens, if a little shorter on the long end, and a good walkaround lens. The kit lens is only really good when I'm worried about damaging a lens for some reason.

Both lens are very close in quality according to the link below, and I do not see the point of keeping both lens. Perhaps you can sells the 18-55mm and put that money toward a nice flash or a portrait telephoto lens.

Pentax SMC-DA 16-45mm f/4 ED AL - Review / Test Report

Pentax SMC-DA 18-55mm f/3.5-5.6 AL - Review / Test Report

 

[iGas]

30mm is not so great for portraits. It's not terrible, but generally people call it a "portrait" lens around the 85mm "equivalent", which means about a 50mm or 60mm for you.

It's certainly not a bad lens, I used to have one on my D2X quite often, but you will get more use out of the super wide.

I'll also second the call to sell one of your mid-range zooms. Having overlap like that just robs you of cash and makes it hard to choose which to use.

Sell the 18-55 and use the money to get a 50mm 1.8 (or 1.7 for Sigma) for the money. This gives you some of the low-light capability of the 30mm along with "portrait" capability.

Then you can do both!

Portrait lens is a lens that give you the comfortable working distance from the camera to the subject, hence anything from 70mm to 300mm for FF cameras.

In the past I tend to use shorter telephoto lenses for portrait in the studio due to space limitation. And, I tend to use 100mm to 150mm for outdoor portrait, with the occasional 200mm or great focal length (35mm).

 

[SecurityTheatre]

The rule of thumb with portraits... the longer the lens, the less perspective distortion. This tends to make people look both more athletic (wider shoulders, jaw, etc) and thinner (flatter features, etc) as well as prettier (generally smaller nose, forehead, longer neck, etc), as well as gives you more control over backgrounds. Shooting portraits with a lens wider than 70mm is a nasty compromise, because it noticeably affects image quality (way more than any difference from one lens to the next.

Here's a good example of focal lengths in mm vs perspective. Notice the "bulging nose, big forehead" doesn't really clear up until about 100mm (35mm equivalent) and it's really not near perfect until around 200mm.

It's not unheard of to see professional models posing in front of a 300mm f/2.8 lens. One of the old SI Swimsuit photographers always used a 600mm and had to have a radio to communicate with the assistants and model.

Obviously, that's taking it to extremes, but it's all in the aim of pointing out that 30mm does not make a good "portrait" lens.

 

[PhoenixEnigma]

iGas: Maybe there's some sample variation? My 16-45mm is a substantially better lens than my 18-55mm - the latter can be about as good at its best, but the 16-45mm is far more consistent about it. The 18-55mm will probably hang around - it's not worth the hassle of trying to sell it for what I'd get, and it's a good beater lens (I throw it on my second body a lot if someone else is using it)

SecurityTheatre: That's more or less what I had started to notice, looking through photos people had taken with each lens (and a mix of others) - there weren't many "That's what I'd take, but better" examples that seemed gear-related. Obviously, there were a lot of people who are just better photographers, but a lot of the places the 30mm seems to shine are not places I'm likely to find myself.

At any rate, thanks for all the info - the 10-20mm has been ordered

Next up might be the 50mm f/1.4 and/or 55-300mm, whenever I have the cash around...

 

[intogamer]

I had to return the Sigma 10-20, due to the noticeable distortion effect it had on shots.

 

[Silenus]

A note about portraits. The suggestions about longer focal lengths are good IF you talking about tight head shots, or upper body portraits. That's what people refer to most of the time when talking portraits. But doing full body or environmental portraits, 30mm would be perfectly fine. Just FYI.