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08-10-2008, 10:53 AM   #1
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Widest fast lens?

Their are lots of 50mm F1.4 out there and there are a sigma 30mm f1.4
Are there wider lenses out there faster than f2.8?

08-10-2008, 10:59 AM   #2
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There is 50/1.2 and FA* 24/2
08-10-2008, 11:12 AM   #3
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QuoteOriginally posted by Phaser Quote
Their are lots of 50mm F1.4 out there and there are a sigma 30mm f1.4
Are there wider lenses out there faster than f2.8?
Sigma has the 20mm f/1.8 as well as the 24mm f/1.8 and the 28mm f/1.8 lenses

I have the 28mm f/1.8 and love it. I actually like it more than the 30mm f/1.4 even though it's slower because I personally think the 28mm has less distortion and is a little sharper wide open (although both the 28 and the 30 are obviously softer wide open than when they are stopped down.

The 20mm is criticized for having a ton of distortion and being VERY soft ... but it is the fastest wide prime I can think of.
08-10-2008, 01:26 PM   #4
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i'm asking because i have the da 40mm 2.8 and i find it a bit on the narrow side and a bit too slow for indoor photo without flash. I like the 18mm end of the kit lens but it's very slow and not that good.
The FA* 24/2 looks nice but it's pricy.
Which lense would serve me my needs the best?

Looking att the prices I guess it is harder to make a fast wide angel than a fast normal lens (since there are that many "cheap" 50mm) allso when you increase the focal range the faster lenses are becomming more expensive. So is it that much easyer/cheaper to make a fast 50mm? and why?
or is the marked demands just not big enough for cheap fast wide lenses?
One thing i can see is that with the crop sensors you need much wider lenses to get wide.

08-10-2008, 01:33 PM   #5
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QuoteOriginally posted by Phaser Quote
i'm asking because i have the da 40mm 2.8 and i find it a bit on the narrow side and a bit too slow for indoor photo without flash. I like the 18mm end of the kit lens but it's very slow and not that good.
The FA* 24/2 looks nice but it's pricy.
Which lense would serve me my needs the best?

Looking att the prices I guess it is harder to make a fast wide angel than a fast normal lens (since there are that many "cheap" 50mm) allso when you increase the focal range the faster lenses are becomming more expensive. So is it that much easyer/cheaper to make a fast 50mm? and why?
or is the marked demands just not big enough for cheap fast wide lenses?
If you like the wide end of your DA18-55mm and the FA24 is too pricey for you then I'd recommend the Sigma 24mm f/1.8 or the Sigma 20mm f/1.8 as a wider alternative to the DA40.

The Sigma 24mm isn't as soft and doesn't suffer from as much distortion as the 20mm does ... but the 20mm is closer to the 18mm end of your kit lens.

Basically, I'd probably suggest getting the Sigma 20 and learning to either live with the softness/distortion or learn to post process your images.

There are sharper wide angle lenses with less distortion ... but they are either more expensive and/or slower than f/2.8.

As for why it's cheaper to make a fast "normal" lens than a fast "wide" lens ... the wider you get the harder it is to control distortion. Also, the wider you get, the larger the glass needs to be to give you a fast aperture. Take a look at the front element on the Canon 15mm f/2.8 fisheye and compare it to the front element on the DA 21mm f/3.2
08-10-2008, 01:57 PM   #6
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distortion i can live with since it's "only" realy visible shooting arcitecture. But if it's too soft on 1,8 or even 2,0 is it worth the extra money for the FA24? (which is double the price of the sigma 24 300$ more and 200$ more than the 20mm)


I know you need more glass for wide but why? is it because you have too "bend the light" much more than on a 50mm? Is it the same with tele lenses or...?

I'm just curious because i wonder why it isn't any realy cheap ultra fast wide lenses out there, (or is it) with terrible iq and destortion. I know you can mount an "addon lens" to another lens and get a fisheye lens but it's not fast.
08-10-2008, 02:52 PM   #7
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FA 35mm f/2.0 is affordable and good lens!
08-10-2008, 02:56 PM   #8
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Fa* 24mm f2 does better wide open with protraits as its bokeh is not too bad. It performs better in dark than in a bright day. People talked about soft corners etc. I found the lens producing not so great colour at times (inaccurate and plain dull green or yellow which cannot be rescued in PP)

Sigma 24mm f1.8 is a better one to own I can assure you if you are using it for landscape purpose.

Ultra fast wide prime is going to be expensive just because there is so much trouble to decrease distorision, flare, weight of the lens and ultimately sharpness at the centre wide open etc. It is not easy to make and not too easy to satisfy the grumpy customers.

08-10-2008, 05:28 PM   #9
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QuoteOriginally posted by Phaser Quote
distortion i can live with since it's "only" realy visible shooting arcitecture. But if it's too soft on 1,8 or even 2,0 is it worth the extra money for the FA24? (which is double the price of the sigma 24 300$ more and 200$ more than the 20mm)
Here's a link to the PBase sample gallery for the Sigma 20mm f/1.8:

Sigma 20mm f/1.8 EX ASP DG RF Lens Sample Photos and Specifications

If you click on the thumbnails to see the larger versions of the images most of the time you can see the EXIF information that indicates what aperture was used for the photograph.

This way you can see what the average joe/jane who uses this lens produces ... and what images look like at a given aperture.
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