[Pentaxor]

the price of the Sigma 28/1.8 tells everything. if the Sigma 28/1.8 is really that impressive, I would had gotten one by now, especially for it's cheap price. Sigma 30 is better and great for portraits. too bad it just can't be that great overall.

honestly speaking, we have a gap around this focal length.

anywhere, with regards to having something better around the 28mm focal length, people would be better off with the slower zooms, be it Tamron, Sigma or Pentax.

[elho_cid]

And the 28 has great macro performance.

Better say close-up. Sigma really makes me mad by touting macro when it is barely close focus.

[Class A]

The 30mm is designed as a normal lens for APS-C so it will most likely outperform the 28mm lens which is designed as a wide angl lens for full frame.

I don't think the Sigma 28mm on FF sacrifices centre sharpness to achieve a more even performance regarding the corners. Hence, it enjoys a "sweet-spot" benefit on APS-C (resolution, vignetting). The 30mm is probably the better choice for some applications (and the 28mm for others), but I don't see how one can make a judgement regarding whether one lens was designed as a wide-angle or not. If it produced a sufficiently large image circle, the 30mm would be a wide-angle on FF too.

the price of the Sigma 28/1.8 tells everything.

This is not helpful.
Not so long ago, the Pentax FA 50/1.4 could be had for US$ 199. Do you think that price told everything about that lens? Do you think it got better with the significant price increase?

if the Sigma 28/1.8 is really that impressive, I would had gotten one by now, especially for it's cheap price.

So what stopped you?
I'm all ears. I own the lens and it has given me fabulous images.

anywhere, with regards to having something better around the 28mm focal length, people would be better off with the slower zooms, ...

Yeah, right.

[Class A]

Better say close-up. Sigma really makes me mad by touting macro when it is barely close focus.

I know that strictly speaking only 1:1 lenses should be called "macros", but there are a number of "Macro" lenses that only magnify up to 1:2 (Tokina 90, Tamron 90/2.5, ...). Are these not macro lenses either? The Sigma 28/1.8 is not miles off the 1:2 magnification mark. Objects are really close to the front lens. The 18cm minimum distance include the length of the lens.

[elho_cid]

I know that strictly speaking only 1:1 lenses should be called "macros", but there are a number of "Macro" lenses that only magnify up to 1:2 (Tokina 90, Tamron 90/2.5, ...). Are these not macro lenses either? The Sigma 28/1.8 is not miles off the 1:2 magnification mark. Objects are really close to the front lens. The 18cm minimum distance include the length of the lens.

1:2 counts in. But not more. Distance from the front pupil of the lens tells nothing. DA14 can focus one inch from the front lens element but it doesn't make it macro with 1:5 reproduction ratio.

[Class A]

1:2 counts in.

Not really.

Distance from the front pupil of the lens tells nothing. DA14 can focus one inch from the front lens element but it doesn't make it macro with 1:5 reproduction ratio.

How much closer to the front element do you want to get?
Given that they probably made the lens as small as possible it seems that it isn't really reasonable to expect a wide angle (regarding FF) to go down to 1:1. Given the FF registration distance, even on APS-C, such lenses have to have a retro-focus design which makes them necessarily larger. So maybe the Sigma 28/1.8 is as "macro" as one can expect for this focal length?

[elho_cid]

DA35 limited is a true macro without excuses. Respectable manufacturers just do not put "macro" in name of lenses that do not achieve at least 1:2. I love wide angles with close focus and that's why I like Da14 so much and I'm considering maybe once getting this Sigma as well. But I won't call the photos I do with them "macro".

[Egg Salad]

I don't think the Sigma 28mm on FF sacrifices centre sharpness to achieve a more even performance regarding the corners. Hence, it enjoys a "sweet-spot" benefit on APS-C (resolution, vignetting). The 30mm is probably the better choice for some applications (and the 28mm for others), but I don't see how one can make a judgement regarding whether one lens was designed as a wide-angle or not. If it produced a sufficiently large image circle, the 30mm would be a wide-angle on FF too.

No, the other way round. The 30mm sacrifices edge performance for better centre sharpness.
My point behind my remark on designed for full frame was that the APS-C-designed lens is thought as a normal lens (classic 50mm) so it should just work like the classic 50mm lens. Meaning that it emphasizes its performance on the center because that's how most portraits are built up. The corners noramlly aren't that important for portraits.

The 28mm lens however is actually a wide angle lens so more even sharpness over it whole image field are much more improtant given the fact that it's much more likely to be used as a landscape lens.

Also with the cropped image cirlce the 28mm lens just has it easier to perform better. Wide open and up to f/2.4 there is a slight edge falloff but beyond that there was never something to complain about. It's almost perfect (ok, it's not but it's really good).

And for the price I paid (225€/300$?) this lens was a steal.

[jeffshaddix]

I've been following both lenses for a while now, but don't own either. There's also the Sigma 24mm 1.8 "macro" to consider, which shares the design with the 28.

One thing I'd like to try is the Sigma 30 1.4 with an attached Raynox 250 close-up filter. There's a nice flickr album with a few example shots. I'm pretty sure with this setup you'd get approx 24mm effective focal length and around 1:3-1:4 close-focus. Plus, you'd have a great low-light portrait/indoor lens with the filter off.

Sorry that was a bit off-topic, but I've been pondering this combo for the last week or so, and it might provide an alternative to the 24 or 28.

[elho_cid]

Maybe I'm unlucky and I got particularly bad copy, but sigma 24/1.8 is not a stellar lens. (In EF mount that is). On Pentax I use FA*24 and I like it a lot more.

[Pentaxor]

So what stopped you?
I'm all ears. I own the lens and it has given me fabulous images.


Yeah, right.

what stopped me is the knowledge that other lenses are better than it with regards to overall IQ performance. for a prime, it does somehow falter in comparison with the others. apart from that, I wasn't impressed at all with the images I have seen. although the lens has a pretty good bokeh for portraits, for general use, it looks pretty mediocre. I'm not saying it is bad, I'm saying it is just not a top performer.
basically, I want something that is atleast a very good consistent performer.

this is the reason why I said that the slower zooms are much better if someone is looking for very good and consistent performance.

[Pentaxor]

I know that strictly speaking only 1:1 lenses should be called "macros", but there are a number of "Macro" lenses that only magnify up to 1:2 (Tokina 90, Tamron 90/2.5, ...). Are these not macro lenses either? The Sigma 28/1.8 is not miles off the 1:2 magnification mark. Objects are really close to the front lens. The 18cm minimum distance include the length of the lens.

there is more than just magnification factor or capabilities involved. one must also consider other macro qualities such as macro resolution, enhancements and certain corrections and performance consistency for such lenses. otherwise, what difference does it make with a 50/1.2 + diopter, ext. tube, reversal ring, bellows, etc... that can do the same job?

macro lenses as far as definition goes may include both capabilities and qualities of a macro lens. I think it would be fair to call the Sigma 28 a pseudo macro but not necessarily a macro equal nor at the same league to it's Sigma 50,70,105,150,180 macro brethren.

[Andrei03]

Thanks for all good advices from you. Where I could find used/second hand lenses for Europe? First I need sigma 18-50 mm f2.8 DC Macro for pentax.

[Class A]

Respectable manufacturers just do not put "macro" in name of lenses that do not achieve at least 1:2.

1. If you are going to play strict (fine by me) then stick to the 1:1 minimum magnification for macros (-> Wikipedia). Why make an exception for 1:2 lenses? Either or, AFAIC.
2. The trick must be not to include the "macro" in the name, but printing it on the lens barrel of a lens with just 0.11x magnification is OK. Phew, lucked out there, Pentax.
3. Just found this shocker from Pentax: "Macro" in the lens name and not a 1:1 magnification.

Seriously, I don't support fraudulent labelling and I'd prefer if only 1:1+ lenses would receive the macro designation. I only pointed out that the Sigma 28/1.8 isn't that far off of a magnification that is sufficient to allow other lenses to be called macros without sniffing at them. To imply that Pentax is a self-respectable lens manufacturer given the two examples above whereas Sigma isn't, well, doesn't make sense to me.

At f/4, which is not a high f-stop for a close focusing scene (DOF) the Sigma 28/1.8 is extremely sharp so it can well be used for "macrops", i.e., gaining further magnification by cropping.

what stopped me is the knowledge that other lenses are better than it with regards to overall IQ performance.

And how did you obtain that knowledge?
To be honest I doubt you are as informed as you could be, e.g., if you tried the lens yourself. But that's OK. I don't need to convince you. I was just wondering what formed your opinion.

...I wasn't impressed at all with the images I have seen.

Well the sample images on the Sigma website are sufficiently impressive for me. Don't mistake the second image with a macro! Just kiddin.

this is the reason why I said that the slower zooms are much better if someone is looking for very good and consistent performance.

Much better? Really? Unless you can report first hand experience and show us why the images of your slow zooms are much better than the images of a Sigma 28/1.8 then I'd abstain from such statements, if I were you.

[elho_cid]

1. If you are going to play strict (fine by me) then stick to the 1:1 minimum magnification for macros (-> Wikipedia). Why make an exception for 1:2 lenses? Either or, AFAIC.
2. The trick must be not to include the "macro" in the name, but printing it on the lens barrel of a lens with just 0.11x magnification is OK. Phew, lucked out there, Pentax.
3. Just found this shocker from Pentax: "Macro" in the lens name and not a 1:1 magnification.

Seriously, I don't support fraudulent labelling and I'd prefer if only 1:1+ lenses would receive the macro designation. I only pointed out that the Sigma 28/1.8 isn't that far off of a magnification that is sufficient to allow other lenses to be called macros without sniffing at them. To imply that Pentax is a self-respectable lens manufacturer given the two examples above whereas Sigma isn't, well, doesn't make sense to me.

Actually I'd be also in favor of calling macro only those lenses to achieve 1:1. But it is not just Pentax but also Canon, Minolta and Olympus to extend this rule to 1:2. So as long as the lens has the rear group separated from the front lens to compensate for focus distance and it's a prime I do not have further objections. Namely if a dedicated attachment maginfier is supplied to provide 1:1.
I agree this Sigma isn't far off and looks interesting. If I only had no bad experience with their 24/1.8 I would really consider it.