[nater]

I'm in the final stages of going through my lenses and deciding what to keep and what to sell, and I'm waffling between the Sigma 12-24mm f4.5-5.6 EX DG and the Sigma 20mm f1.8 EX DG DF RF. I haven't done a lot of photography in the last few years, but I'd really like to get back into it. My camera right now is a K-5, and someday I'd really like to get a full-frame Pentax body, so APS-C and full-frame lens performance will both ultimately matter to me.

In my mind, the 12-24mm is a good lens primarily for outdoor photography, and the zoom comes in really handy for landscape shots when I can't easily move closer or farther away, giving a lot of flexibility for framing. The 20mm f1.8 gives me the ability to do indoor photography in natural light, though I didn't find myself using 20mm indoors much. 20mm outdoors is much more useful, but it is just one focal length where I can stand can make or break that focal length. F1.8 opens up a broader range of lighting possibilities and stopped down, I think brings better resolution and lower distortion than the 12-24mm. I've always wanted to do more night sky photography, and maybe the Sigma 20mm could be used for that, though I think if I was serious about that there are a number of manual focus ultrawide primes that are better at the task, right? Anybody have thoughts/experiences with lenses like this? Should I consider selling them both and getting something else that could serve me better? (Or maybe just sell them both and fall back to my Tokina AF 19-35mm f/3.5-4.5, which I like and is lighter and easier to pack... butt I'm having a hard time estimating out how much I'd miss the 12-18mm range...)

[ramseybuckeye]

Keep both

[ehrwien]

Keep both

+1

If you sell either one and get a K-1 sometime, you'll regret having sold the lens you did.

(disclaimer: I have neither of those lenses, but I have the K-1, and have read great things and seen beautiful pictures made with both lenses)

[LensBeginner]

Sell both and buy the 10-20/3.5 or the 8-16/4.5-5.6
Emphasis on the "or"

[pepperberry farm]

I'm not a fan of the 'either - or' school - keep them both...

[wadge22]

It sounds like you are more of a zoom shooter, so if you plan to only keep one, keep the zoom.

[UncleVanya]

Keep both

See above.

[pres589]

Sell the 20 and buy a DA 15 Ltd.. SMC with the proceeds. Keep the 12-24 because 15 isn't really that wide on crop and that is supposed to be a decent zoom lens.

[Joetitch]

The words sell and lens should never appear in the same sentence.
LBA dictates this.😊

[Madaboutpix]

If both are good copies, and I read nothing suggesting they aren't, keep them both. Having the choice between competent zooms and primes in one's kit is a privilege I wouldn't want to give up. The zoom gives you flexibility, the prime maximum imaging power and fast aperture at its particular focal length.

[kypfer]

Other than for depth-of-field subject-isolation issues, the zoom on a tripod should be as good or better indoors than the prime.
Personally I'd go for flexibility rather than maximum aperture … but I do like both
As for night sky work … you'd need to ensure that the lens gives the performance you require before committing … I've found some (cheaper/older) wide aperture primes suffer from annoying coma wide open, so whilst they are easier to frame and focus with, they're usually used stopped down a bit for performance.
Good luck!

[aslyfox]

I'm in the final stages of going through my lenses and deciding what to keep and what to sell, and I'm waffling between the Sigma 12-24mm f4.5-5.6 EX DG and the Sigma 20mm f1.8 EX DG DF RF. . . . My camera right now is a K-5, and someday I'd really like to get a full-frame Pentax body, so APS-C and full-frame lens performance will both ultimately matter to me.

. . . F1.8 opens up a broader range of lighting possibilities and stopped down, I think brings better resolution and lower distortion than the 12-24mm. I've always wanted to do more night sky photography, and maybe the Sigma 20mm could be used for that, though I think if I was serious about that there are a number of manual focus ultrawide primes that are better at the task, right? . . .

my 2 cents

I agree with others, if at all possible, keep both

however if you are going to sell, think about upgrading your camera, if possible either to a more advanced ASP-C Pentax or the K 1 or K

You may find a newer camera that would fit your needs better


if you aren't aware of this tool, I like to use it a lot and find it to be a very useful tool:

https://www.pentaxforums.com/forums/pentax-cameras-compared/?c1=Pentax%20K-5...=Pentax%20K-70



keep an eye on the PF Marketplace for opportunities, it can be sorted by Country. I have had good luck dealing with other members there

The Pentax Marketplace | Buy & Sell Pentax Cameras and Lenses (United States) - PentaxForums.com

[ramseybuckeye]

Another consideration in selling lenses is that in my opinion lenses are really not selling all that well these days. Look at the listings different places, not what the sellers are asking for, but actual sold listings.

[UncleVanya]

Sell the 20 and buy a DA 15 Ltd.. SMC with the proceeds. Keep the 12-24 because 15 isn't really that wide on crop and that is supposed to be a decent zoom lens.

While I love my da 15 - it doesn’t fit the brief here. It isn’t much faster than the zoom, it isn’t an astrophotography lens, it isn’t a better indoor lens, and it doesn’t support full frame which is a stated future goal.

[nater]

Another consideration in selling lenses is that in my opinion lenses are really not selling all that well these days. Look at the listings different places, not what the sellers are asking for, but actual sold listings.

I've noticed that, looks like I've got bad timing to finally clean up my collection. I have at least a dozen other lenses I am selling, and I've wanted a Pentax full-frame DSLR since basically forever, and it would great if I could finance that through selling my excess gear at this point. Thanks to the feedback here, I'll keep the Sigma 12-24mm at least. Is it worth considering selling/trading in my equipment somewhere else rather than selling it here in the marketplace, or is that still my best bet?