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Archive 2013 · Sigma Announces 18-35 f/1.8 DC HSM Art
  
 
saneproduction
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p.4 #1 · p.4 #1 · Sigma Announces 18-35 f/1.8 DC HSM Art


They are confused, light gathering power of the lens is the same on FF or Crop. The DOF at similar apertures at equivalent focal lengths is what is different.


Apr 20, 2013 at 05:57 PM
Sven Jeppesen
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p.4 #2 · p.4 #2 · Sigma Announces 18-35 f/1.8 DC HSM Art


BrianO wrote:
Can you explain this to me? My Sekonic L-758DR light meter doesn't ask what sensor format I'm using, so I have always though an f-stop was an f-stop.


This is how it works. I did copy it from theSuede's post about this lens in the alt forum

"No, what's impressive is that it has THE SAME light gathering ability as a FF 2.8 lens.

The F-stop tells you how much light per square mm the lens will put through. When you multiply that by sensor (or film) area, you get "light gathering ability".

APS has either 2.6 (Canon) or 2.3 (the rest) times smaller area than FF. This means that you need 1+1/3 stop larger apertures on APS to gather the same amount of light per second as on 36x24mm.

F2.8 minus 1+1/3Ev = F1.8.

F-stop tells you "exposure" - which is a per-area measurement. This is a dead metric. It is totally irrelevant in a digital sensor until you know the sensor area.




Apr 20, 2013 at 09:12 PM
jj_glos
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p.4 #3 · p.4 #3 · Sigma Announces 18-35 f/1.8 DC HSM Art


The metering must be screwed on my bodies, as both the 1Ds2 and 7D meter identically on the same scene (although since I recently had work done by Canon on the 1Ds2 it consistently under exposes by around a stop...).


Apr 21, 2013 at 01:11 AM
BrianO
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p.4 #4 · p.4 #4 · Sigma Announces 18-35 f/1.8 DC HSM Art


Sven Jeppesen wrote:
...F-stop tells you "exposure" - which is a per-area measurement. This is a dead metric. It is totally irrelevant in a digital sensor until you know the sensor area.


Totally irrelevant?

If I meter a scene with my light meter and it tells me to set my camera for f/1.4 at 1/125 second at ISO100 it doesn't matter if I'm using an APS-C camera, a "full-frame" camera, or an 8X10 sheet film view camera. All will yield the same exposure.

If I then set the "full frame" camera to f/2.8 it will be underexposed by 2 stops.

I'd say it's the sensor size that is totally irrelevent!



Apr 21, 2013 at 04:42 AM
EB-1
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p.4 #5 · p.4 #5 · Sigma Announces 18-35 f/1.8 DC HSM Art


I'm missing the appeal of this lens, unless it is priced very reasonably. It is not an FX lens nor does it have VR. Modestly pricked bodies like the D600 have good high ISO performance and are relegating DX to the lower levels, where most buyers are not willing to spend a lot of money on a short-range normal zoom. DX sensors are noisier than similar pixel-count FX sensors so f/1.8 brings parity to f/2.8 on FX at best.

EBH



Apr 21, 2013 at 02:35 PM
BostonGreg
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p.4 #6 · p.4 #6 · Sigma Announces 18-35 f/1.8 DC HSM Art


LOVE the new look and feel of the SIGMA Arts! SIGMA is really stepping it up and I'm excited to try this new wide zoom. I got a fabulous copy of the 35 Art and sold my Canon 35L immediately, image quality from my 35L wasn't even close, although I feel I didn't have a great copy. Hats off to Sigma, would love to see an 85 f1.2 Art!


Apr 21, 2013 at 05:51 PM
 

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EB-1
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p.4 #7 · p.4 #7 · Sigma Announces 18-35 f/1.8 DC HSM Art


What does the Art stand for?

EBH



Apr 21, 2013 at 05:59 PM
BrianO
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p.4 #8 · p.4 #8 · Sigma Announces 18-35 f/1.8 DC HSM Art


EB-1 wrote:
What does the Art stand for?


Sigma Corporation wrote:
Starting immediately, all newly produced interchangeable lenses from Sigma will be designed for and organized into one of three product categories: Contemporary, Art and Sports. Each line has a clearly defined concept to guide shooters in the selection of the right lens for their photographic interests.

The concept of these categories are as follows:

• Contemporary – These lenses incorporate the very latest technology and keep size and weight to a minimum, without compromising their advanced optical performance or utility. High-performance, versatile, compact and superbly portable, these lenses will be largely comprised of standard zooms, telephoto zooms and
...Show more

Sounds like a lot of marketing mumbo jumbo to me, but whatever flips their pancakes I guess.



Apr 21, 2013 at 10:58 PM
RobDickinson
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p.4 #9 · p.4 #9 · Sigma Announces 18-35 f/1.8 DC HSM Art


EB-1 wrote:
I'm missing the appeal of this lens, unless it is priced very reasonably. It is not an FX lens nor does it have VR. Modestly pricked bodies like the D600 have good high ISO performance and are relegating DX to the lower levels, where most buyers are not willing to spend a lot of money on a short-range normal zoom. DX sensors are noisier than similar pixel-count FX sensors so f/1.8 brings parity to f/2.8 on FX at best.

EBH


Yes it brings parity. You dont have to buy an expensive ff body.

A cheap rebel and this not so cheap not so small lens will perform very nicely.
Not my thing but it may tempt others, at least we now have that option!



Apr 21, 2013 at 11:11 PM
pipspeak
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p.4 #10 · p.4 #10 · Sigma Announces 18-35 f/1.8 DC HSM Art


I worry when I see so much marketing guff... such efforts to justify a product make me think I'm paying a healthy markup on a product that may or may not deliver. "Designed to meet the expectations of users who value a creative, dramatic outcome"?? What does that even mean?!

On a more serious note, how do folks who own higher-end Sigma lenses find that they hold up over time? Can they take the sort of abuse that some professionals dish out to Canon's L lenses, for example?



Apr 22, 2013 at 01:51 AM
EOS20
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p.4 #11 · p.4 #11 · Sigma Announces 18-35 f/1.8 DC HSM Art


Hands on with the Sigma 18-35mm F1.8 DC HSM:

http://www.dpreview.com/previews/sigma-18-35-1-8




Apr 22, 2013 at 11:50 AM
Yakim Peled
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p.4 #12 · p.4 #12 · Sigma Announces 18-35 f/1.8 DC HSM Art


They are really not saying much...

Happy shooting,
Yakim.



Apr 22, 2013 at 03:05 PM
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