p.1 #1 · Sigma 18-35 f/1.8 hands-on and samples online
Korean website lcap.tistory.com, posted a review on the Sigma 18-35 f/1.8 DC HSM lens.
They've tested the new lens for distortion, light fall-off, sunstars and posted tons of sample images.
Dpreview also posted a hands-on with the Sigma 18-35mm F1.8 lens. Here is an excerpt from their article:
"Sigma's choice of F1.8 as maximum aperture isn't a coincidence; it means that the lens will offer the same control over depth of field as an F2.8 zoom does on full frame. What's more, it will also offer effectively the same light-gathering capability as an F2.8 lens on full frame. By this we mean that it will be able to project an image that's just over twice as bright onto a sensor that's slightly less than half the area, meaning the same total amount of light is used to capture the image. This is important as it's a major determinant of image quality. Essentially it means that APS-C shooters will be able to use lower ISOs when shooting wide open in low light and get similar levels of image noise, substantially negating one of the key advantages of switching to full frame."
p.1 #6 · Sigma 18-35 f/1.8 hands-on and samples online
It's still a pointless term. Exposure will remain the same across different sensor sizes. A full frame f2.8 lens may have more "light gathering ability" than an APS-C lens at f2.8 but it doesn't matter one bit, because your sensor needs less light because it's smaller. The end result is the same exposure. Again a pointless term.
I don't care what light a lens might be gathering that my sensor can't see.
p.1 #8 · Sigma 18-35 f/1.8 hands-on and samples online
stan23 wrote:
samples look amazing... They really need to make a FF version of this lens.
Possible but wont happen. It would be crazy heavy (1,5 kg or so) and had a really big front element. Not mentioning that it would be seriously expensive.
And dunno, what would be point?
This was created for SD1M, cause it gives sorta 27-50/2.8 equiv at least as far as FOV and DOF goes.
I guess things could be pushed somewhere to f2.2 or f2.4 for regular FF zoom, but that gain isnt worth it and neither its needed, cause ISOs can go skyhigh these days.
I will just guess (again) here, but in not-so-distant future, well made 24-70/4 will be more used than 24-70/2.8 cause ISOs will be easy able to keep up and if it will be era of some hybrid mirrorless cams, then weight and size will be important too.
A lot of photographers these day use rather IS based systems with slower f-stops than high speed lens.
p.1 #9 · Sigma 18-35 f/1.8 hands-on and samples online
andyjaggy82 wrote:
It's still a pointless term. Exposure will remain the same across different sensor sizes. A full frame f2.8 lens may have more "light gathering ability" than an APS-C lens at f2.8 but it doesn't matter one bit, because your sensor needs less light because it's smaller. The end result is the same exposure. Again a pointless term.
I don't care what light a lens might be gathering that my sensor can't see.
No, that IS the point. A smaller sensor compared to a larger sensor with an equal MP count will on average need a stop or more of light in order to achieve the same noise levels. Placing a 2.8 lens on a DX vs FX will yield very different results in very challenging low light situations regardless if the exposure remains the same. The fact of the matter is there is no F1.8 ZOOM available on an FX format, which is why Sigma says this levels the playing field between DX and FX somewhat.
Having the ability to shoot events in the same ballpark as you would a prime, but with a zoom is HUGE!
p.1 #10 · Sigma 18-35 f/1.8 hands-on and samples online
andyjaggy82 wrote:
It's still a pointless term. Exposure will remain the same across different sensor sizes. A full frame f2.8 lens may have more "light gathering ability" than an APS-C lens at f2.8 but it doesn't matter one bit, because your sensor needs less light because it's smaller. The end result is the same exposure. Again a pointless term.
I don't care what light a lens might be gathering that my sensor can't see.
Your sensor doesn't need less light. It just captures less light. The exposure numbers are the same (aperture number, shutter speed, ISO), but the amount of noise is higher on APS-C because it captures less light overall and DOF is larger as well. To make the end result equal to FF you'd shoot the APS-C at f/1.8 and FF at f/2.8. That's in theory, which doesn't quite work out that way regarding noise because of sensor tech differences.
Light gathering ability is in no way a pointless term. It might not affect the way you shoot nor do you care what it means, but that doesn't make it meaningless.
p.1 #11 · Sigma 18-35 f/1.8 hands-on and samples online
Mescalamba wrote:
Eh, ugh ehm..
Ok, call me stupid, but I always thought that if I have lets say 50/1.4 on APS-C and on FF I get same ISO and shutter speed?
Yes, but that doesn't mean you will get the same image quality. The APS-C camera will give you more noise for an equivalent ISO than the FF. The idea here is that this lens takes advantage of the small image circle of the APS-C camera to produce the 1.8 zoom, something which doesn't exist for FF.
So if you take a shot at 50mm f/2.8 1/50s and ISO 1600 on FF you could take the same image from the same spot at say 32mm f/2 1/50s and ISO 800 on APS-C and end up with similar noise levels in the two images.
p.1 #12 · Sigma 18-35 f/1.8 hands-on and samples online
Mescalamba wrote:
Possible but wont happen. It would be crazy heavy (1,5 kg or so) and had a really big front element. Not mentioning that it would be seriously expensive.
And dunno, what would be point?
This was created for SD1M, cause it gives sorta 27-50/2.8 equiv at least as far as FOV and DOF goes.
I guess things could be pushed somewhere to f2.2 or f2.4 for regular FF zoom, but that gain isnt worth it and neither its needed, cause ISOs can go skyhigh these days.
I will just guess (again) here, but in not-so-distant future, well made 24-70/4 will be more used than 24-70/2.8 cause ISOs will be easy able to keep up and if it will be era of some hybrid mirrorless cams, then weight and size will be important too.
A lot of photographers these day use rather IS based systems with slower f-stops than high speed lens....Show more →
Im not a lens engineer, but I don't see why it can't be possible - if the market demanded it.
p.1 #13 · Sigma 18-35 f/1.8 hands-on and samples online
Mescalamba wrote:
Possible but wont happen. It would be crazy heavy (1,5 kg or so) and had a really big front element. Not mentioning that it would be seriously expensive.
And dunno, what would be point?
This was created for SD1M, cause it gives sorta 27-50/2.8 equiv at least as far as FOV and DOF goes.
I guess things could be pushed somewhere to f2.2 or f2.4 for regular FF zoom, but that gain isnt worth it and neither its needed, cause ISOs can go skyhigh these days.
I will just guess (again) here, but in not-so-distant future, well made 24-70/4 will be more used than 24-70/2.8 cause ISOs will be easy able to keep up and if it will be era of some hybrid mirrorless cams, then weight and size will be important too.
A lot of photographers these day use rather IS based systems with slower f-stops than high speed lens....Show more →
And further down the track we'll be using a 24-70 f/5.6 then maybe a 24-70 f/8. We shoot FF so we can have complete control over DoF, otherwise we buy a crappy P&S. I will never buy a 24-70 f/4 even if ISO 200000 is perfectly clean, hell f/2.8 is too slow sometimes on a 24-70 and I'd much prefer a lens that was f/2.
p.1 #14 · Sigma 18-35 f/1.8 hands-on and samples online
Thing is, market doesnt demand behemoth standart zooms.
Good point about DOF. Sure I would like zoom with f/2. Im just quite positive that lugging it around wouldnt be much fun..
About f/2 zooms. Olympus made two for 4/3s. Which is sorta interesting. Whats more interesting is size of those things. And thats only to cover 4/3 sensor! Imagine how big it would need to be to cover FF. Btw. it was tested it really does cover only 4/3.
p.1 #15 · Sigma 18-35 f/1.8 hands-on and samples online
andyjaggy82 wrote:
It's still a pointless term. Exposure will remain the same across different sensor sizes. A full frame f2.8 lens may have more "light gathering ability" than an APS-C lens at f2.8 but it doesn't matter one bit, because your sensor needs less light because it's smaller. The end result is the same exposure. Again a pointless term.
I don't care what light a lens might be gathering that my sensor can't see.
This is true , but if you take into account the better iso performance of the larger sensor then being able to shoot at 1 and a bit stops lower (1.8 v 2.8 ) does have a positive effect where noise is concerned .
p.1 #16 · Sigma 18-35 f/1.8 hands-on and samples online
stan23 wrote:
samples look amazing... They really need to make a FF version of this lens.
I feel a bit stupid to ask, but I simply canīt find ANY sample images on that page... all it shows are images of the lens itself ... can you probably point me to the samples?
p.1 #17 · Sigma 18-35 f/1.8 hands-on and samples online
andyjaggy82 wrote:
It's still a pointless term. Exposure will remain the same across different sensor sizes. A full frame f2.8 lens may have more "light gathering ability" than an APS-C lens at f2.8 but it doesn't matter one bit, because your sensor needs less light because it's smaller. The end result is the same exposure. Again a pointless term.
I don't care what light a lens might be gathering that my sensor can't see.
Agree. It muds the water quite a bit.
Now there are people around swearing that it means that it exposes like f/2.8 on FF (meaning same ISO and shutter speed).
p.1 #18 · Sigma 18-35 f/1.8 hands-on and samples online
I understand and agree with everything posted above. I think what really annoys me about the term is that some people talk like a full frame 2.8 zoom is better than a 2.8 crop zoom because it has "more light gathering" ability. I guess that's technically true, but really kind of pointless in the real world, where your crop sensor can't use that light anyway.
So some people discredit this lens claiming that's it's really just the equivalent of a full frame 2.8 zoom, because it "gathers the same amount of light" as a full frame 2.8 zoom. As if how much light it is gathered, regardless of if the sensor can see it or not, is the really important thing.
In the real world however it allows APS-C users to get that much faster of a shutter speed, or that much lower of an ISO setting that they could have gotten before, at least not in a zoom
So I think "light gathering ability" is a confusing term at best, downright misleading at worst, thus my original comment that it's the new marketing buzz word.
p.1 #19 · Sigma 18-35 f/1.8 hands-on and samples online
Light gathering ability due to the sensor size is a difference between crop and full frame. Although of course if you are in a situation where you are focal length limited, any cropping of the full frame image reduces any perceived advantage. Again the ISO performance of the crop sensor in relation to the full frame sensor will also impact any results.
With plenty of light at ISO 100 the differences may not concern you, but full frame advantages in noise are there as you go up the scale. A new better performing crop sensor from Canon would be nice
p.1 #20 · Sigma 18-35 f/1.8 hands-on and samples online
Kusie wrote:
I feel a bit stupid to ask, but I simply canīt find ANY sample images on that page... all it shows are images of the lens itself ... can you probably point me to the samples?
Thanks a bunch!
Kusie
It seem like the sample images were removed from the Korean blog...
