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10-14-2009, 03:10 AM - 1 Like   #1
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Let's talk about Sigma 24 1.8 EX Asph Macro

Hi All,
I have been on the market for a while, looking for a fast (and possibly cheap) prime lens for my old k100d. I got very excited last week, when I found a good bargain on eaby: a Sigma 24 1.8 EX for as much as 200. What I knew about this lens, reading many forums on the net, wasn't excactly encouraging: it lacks sharpness wide open, has distortions, not to mention vignetting, aberrations, flares and ghosts. Moreover, it weights nearly as much as the camera body and the EX finish is well known to be very fragile. Well, I bought it

To be honest, I would have preferred the 28 1.8, because it is the perfect "normal" for an APS-C sensor. But, the bargain was on this one and I decided that a 24 could be a 28 with a couple of step towards the subject (well, I know this is not exact..)

So, I attached that huge piece of glass to my k100d and did some quick and dirt shot, first in my house and then, waiting for the sun and trying to see if such a fast prime could be used even when there's plenty of light.

First interesting feature: the lens is macro. so you can focus as near as 18cm. Given the size of the lens, that means that you can place the subject nearly attached to the front lens. To be honest, 24mm is a weird focal lentght for a macro lens, but it's not unusable; it allows you to take some interesting shot of macro subjects among with beautifully blurred background.

So, here come the test pictures. Shots are RAW and converted using Pentax Photo Laboratory, no post processing except the white balance. No extra sharpness, no extra saturation, nothing.

So, lets start with a violet cow:

f4, iso1600:



crop 100%:



Other cows at f2.8, iso400:



it's a nice bokeh, isn't it? it's only a 24mm....

other portrait at f2.8m, iso400



crop 100%:



another macro at f2.8 iso200



crop on the focus zone:



another classic subject: a flower, f5.6, iso200



crop 100% (focus on the petals):



f8, iso200



crop 100%:



I decided to make a few non-macro shots, so I managed to find another subject, a little bigger:



f8 e iso200, crop 100%:



Another landscape, f8 and iso200:



crop 100%:



So, what happens when the sun is not behind the camera? Sigma lenses are renowned to be flare-prone, so lets turn the camera towars the sun:

f8, iso200



crop100%:



With the sun nearly on the frame, the contrast remains good: f8 e iso200:



With the sun IN the frame, you can easily see all the 10 lenses and the optical scheme on the picture:



So, what about this lens? I like it, even though I've not tested it extensively. I like fast primes, and I've never been one on my DSLR. To purchase a FA* 24/2 or a 31 1.8 I would have spent 3 or 4 times the money I spent for this one, so I know this lens is kinda a compromise but, to me, it seems worth the money.

If you are interested, I will publish the next test. I will try this lens @f1.8 and, say, 400 iso and the 18-55 kit lens @24mm f4 and 1600 iso.
which of the 2 pictures will be better? Sigma fast primes are known to be very soft at full aperture, but will this softness be better than the noise of the increased sensitivity? let's see!

ciao
maurizio

10-14-2009, 03:16 AM   #2
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QuoteOriginally posted by mauriziolippa Quote
Hi All,

..

So, what about this lens? I like it, even though I've not tested it extensively. I like fast primes, and I've never been one on my DSLR. To purchase a FA* 24/2 or a 31 1.8 I would have spent 3 or 4 times the money I spent for this one, so I know this lens is kinda a compromise but, to me, it seems worth the money.

...

ciao
maurizio

Thanks for review!

This lens seems definitely to be worth the money paid. The center area in-focus looks very good. Please make sure to post few 1.8 samples, preferrably portraiture, and maybe some more close-ups. I`m really interested in how this lens conveys volume, and how its bokeh is.

PS. might be a good idea to attach your short review in the reviews section for 3rd party lenses.
10-14-2009, 11:14 AM   #3
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Sorry to snipe your thread, but I've been racking my brains over these Sigma fast wide primes for a few weeks now. There's 20mm, 24mm & 28mm all at f1.8, and I think all have Macro capabilities. Then there's also the 30mm f1.4 that people are loving.

I'm planning on using mostly for low light, indoor, people shots (have the DA 12-24 for landscapes). If image quality in this setting is close, the additional Macro capabilities and wider view could be well worth losing only .4 aperture. Plus they are a few clams cheaper.

Beyond that, there are still are a few options at 50mm (including Pentax FA) round the same price range, but I think I want the wider view so I can have the option of standing close to the subject.

Opinions would be much appreciated!
10-14-2009, 02:19 PM   #4
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QuoteOriginally posted by Muggins Quote
Sorry to snipe your thread, but I've been racking my brains over these Sigma fast wide primes for a few weeks now. There's 20mm, 24mm & 28mm all at f1.8, and I think all have Macro capabilities. Then there's also the 30mm f1.4 that people are loving.

I'm planning on using mostly for low light, indoor, people shots (have the DA 12-24 for landscapes). If image quality in this setting is close, the additional Macro capabilities and wider view could be well worth losing only .4 aperture. Plus they are a few clams cheaper.

Beyond that, there are still are a few options at 50mm (including Pentax FA) round the same price range, but I think I want the wider view so I can have the option of standing close to the subject.

Opinions would be much appreciated!
Many months ago when the Pentax FA 35mm f2 dropped off the US market (it had been readily available earlier this year for $300 new), I searched for something else, bought the Sigma 28mm f1.8 and have been very happy. It was only $60 more than the FA 35mm was, it's a more 'normal' lens on APS-C than the 35mm would be, it's also backward compatible with old K-mounts so I can use it on my film bodies, it has Macro unlike the FA 35mm, it's .2 stop better than the FA 35mm, and the build quality and optical quality is excellent. Some might complain about the size of the lens, but for what it offers and for it's cost, no complaints from me.

One minor, odd thing about the lens - EXIF data reports f1.7 when the lens is f1.8 - what is the reason for that?

10-14-2009, 02:34 PM   #5
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I don't want to step on people's toes here, but I actually think the Sigma 24mm on APS-C is very comparable to the Pentax FA*24mm for much less $$$

My personal favorite of the 3 fast wide angle primes from Sigma (20mm, 24mm & 28mm)
10-14-2009, 02:40 PM   #6
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Well done, looking good. Congrats on the lens

Darren M. was a big fan, of both the Sigma 28/1.8 and the 24/1.8.
The 30/1.4 also has a lot of followers
10-14-2009, 04:05 PM   #7
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Have had it for a few years and have taken some great shots with it & the trusty DS. Unfortuneatley the 24 f1.8 now sits in its case at the back of the cupboard awaiting repair. It rattles when shaken....so something has came adrift inside.

Other than the flare and size this is a good lens.
10-14-2009, 05:03 PM - 1 Like   #8
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I have been thinking about this lens. I have the 28 1.8 it is a wonderful lens. Im not much into macro shots, but when I first purchased that lens I did some macro tests shots of my exgirlfriend's nipples @ f2....damn that lens is sharp and nice bokeh hmmm...wonder where those images are, i need to dig them up.

My lens also reads 1.7 and not 1.8 wide open on my K20, oh well

10-14-2009, 07:53 PM   #9
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QuoteOriginally posted by ramair455 Quote
I did some macro tests shots of my exgirlfriend's nipples @ f2....damn that lens is sharp and nice bokeh hmmm...wonder where those images are, i need to dig them up.
Yes, dig them up and post them so that we can check whether you got the focus right.

I can only say good things about my copy of the Sigma 28/1.8.

Perhaps it really is a f/1.7 on Pentax mount?
10-14-2009, 09:42 PM   #10
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QuoteOriginally posted by Class A Quote
Yes, dig them up and post them so that we can check whether you got the focus right.
You know..i just might do that...she would never know
10-19-2009, 05:53 AM   #11
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Well, now let's answer the following question: given the (low) available light, it's better to step up the iso sensitivity to 1600 and use the 18-55 kit lens at f/4 or maintain -say- iso400 and use the Sigma at full aperture?

(obviously, there are pictures that can be taken only with the sigma at full aperture and 1600 iso; in these scenarios, there's no way to take the picture with the kit zoom)

The following shots are directly converted from RAW using Pentax Photo Lab, no further elaboration applied but the white balance. The scene is as following:



In the following crops, the left crop is from 18-55 kit lens (version I), the right crop is from the Sigma lens.

Let's start with f4-iso1600 versus f1.7-iso400

center:



border:



I don't know if the corner softness in the sigma shot is a true corner softness of a filed of view curvature, don't have idea...

Given the same iso sensitivity (200), f4, center:



border:



f8, iso200, center:



border:



In my opinion, Sigma is perfectly usable even at full aperture, if you put the subject in the center of the image. If the subject is placed near the extreme borders, you have to close a bit.

If you want the original images, drop me a pm

ciao
m
03-01-2011, 10:41 PM   #12
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Yeah, I know this is a huge thread resurrection, but I haven't seen a lot on the Sigma 24 1.8 and I took it out for a spin the other day so I thought I'd share some of the pictures I've taken with it. I have a few lenses in this range that I usually use more (pentax 12-24, the sigma 18-50 2.8 or the tamron 28-75 2.8), but on the occasions I am using this lens, I've liked using it. It is a touch large (almost the size of the Pentax 12-24) especially for a prime, but the focal length is great for candids and it's nice that it's usable at f1.8. The bokeh isn't as smooth as say the 77 or 50-135, but I like it for a wide-ish angle. The biggest beef I have with it is not really the fault of the lens - I have too many other lenses that are easier to use (ie zooms). And when I'm traveling, space is a major consideration on what I bring and this lens is just too big for the bags I carry. But it's a good specialty lens that I like having in my kit.



Camera Pentax K-7
Exposure 1/6400 sec
Aperture f/1.4
Focal Length 24 mm
ISO Speed 100



Camera Pentax K-7
Exposure 1/6400 sec
Aperture f/1.4
Focal Length 24 mm
ISO Speed 100



Camera Pentax K-7
Exposure 1/4000 sec
Aperture f/1.4
Focal Length 24 mm
ISO Speed 100



Camera Pentax K20D
Exposure 0.04 sec (1/25)
Focal Length 24 mm
ISO Speed 640
Exposure Bias +0.7 EV



Camera Pentax K20D
Exposure 0.04 sec (1/25)
Focal Length 24 mm
ISO Speed 640
Exposure Bias +0.7 EV
03-05-2011, 07:30 PM   #13
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I wouldn't mind grabbing up a copy of this lens, it's certainly unique - there's no other wide angle prime that's this fast AND close-focus!

In fact, I think this+FA31 would make a great wide angle team.
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