Faster Glass ...or Image Stabilizer?
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noisephotographer wrote:
With the 15-45mm it is possible to get sharp 15mm or 16mm photos with an exposure time of 1/2s.
In a nutshell, the 32mm f/1.4 STM lens gives the user all the light they need at handheld speeds... usually without the need to rely on high ISO settings. It's quite liberating to work with bright lenses and the added bonus is in the Bokeh - plus one other thing that I'll mention below.
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The 15-45mm lens has an f/3.5 aperture when opened to its widest setting. That's not particularly suitable for lowlight work other than completely motionless scenes - but I can appreciate how useful an I.S, system is. I think I saw a shot taken with this lens by a member image - a shot taken at low speeds (foggy village in the morning) which was quite a lovely shot. But I'm sure others would agree than half a second exposure (0.5 sec) is a very short amount of time. For shots like that I'd probably be shooting a landscape and that would demand an even narrower aperture and a tripod to get right... preferably something closer to f/6. Bit it is a wider lens at 15mm and that's where the f/3.5 aperture ranges from. It jumps pretty quickly to a smaller aperture as you use the zoom with that lens. If you're traveling, you might find it easier to shoot like that if you don't have a tripod on hand. But these are two very different lenses. The 15-45mm lens is more of a landscape and general purpose lens and this is why Canon selected it as their Kit lens to replace the 22mm lens. An f/3.5 landscape shot is probably going to be quite sharp.
With the 32mm f/1.4 it's extremely hard to get sharp 1/20s photos without any help.
I agree. But nobody needs to routinely use a lens at 1/20 sec and it's not particularly desirable to do so. Yet the fact that you can makes it useful as a feature. I just had a cat sitting on my lap but was able to reach my EOS M6 camera with one hand. I then dropped the shutter speed to 0.5 second but was unable to capture an image at that speed. It was too slow and only one out of 6 shots was usable with the camera braced against my knee with plenty of movement from my and the cat. But cranking the settings to f/1.4 + 1/15 sec + ISO 400 (bear in mind that it's night here and my office is pretty dark) was different. And that gave me 6/6 shots that were sharp. It was handheld and I still brought my knee up to use as a brace. Now I could easily crank the shutter speed up to 1/30 second for added stability but the shots I was getting at 1/15 were fine. In the real world I'm likely to pick a safe exposure time of 1/60 at night if stationary. In daylight or when moving about, surely 1/80 sec is the ideal minimum with the 32mm lens. The wider the lens, the longer the shutter speeds that can be used. The IS on the 11-22mm lens is very good but I can't get much out of it after sunset. It's just too dark to use at f4, even with the IS active.
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1/20 sec qualifies as a "long exposure". It will render movement from your hands if they exceed the ability of the Stabilizer and the subjects in the scene will move and therefore blur. I generally won't shoot a portrait at 1/40 sec, let alone slower, without a tripod or some sort of stabilizing surface. Low and Medium levels of Noise can be easily removed with software in many instances and the times where NR is critical is with skin tones for portraits... and you really don't ever want to shoot portraits at 1/20 sec. I had to take a picture of people talking in a darkened restaurant the other night and I had no choice but to use a higher ISO so that I could keep my shutter down low... but a 1/20 sec exposure with IS would have blurred all three subjects in the shot. I was fine with some peppery grain in the shot rather than blurred people with less noise and less light.
Therefore even the 15mm f/3.5 IS can lead to less noisy photos than the Ef-m 32mm, if there are no moving objects and if one doesn't crop the 15mm photo.
Hold on ... an f/3.5 exposure, even stabilized at half a second (let alone 1/20 sec) ... isn't going to compare to the amount of light coming through an f/1.4 lens at 1/40 sec. The trees move, the people move and the cars and everything else moves. That leaves indoor lowlight environments. If you're shooting a picture of a meal on a plate of a book on a shelf, sure... that will work. But your picture will have a greater DOF which will have an aesthetic effect on your results. Try photographing a pet or a person indoors with that method and you'll have issues with movement. One of the very best image stabilizers I've used enabled me to take a 4 second exposure that was handheld - of the Orion Nebula (see below). I was crouched down with my back against my car and shooting blindly since the nebula itself isn't visible to the human eye. It just looks like a star. The Stabilizer did a marvelous job since this was a 400mm lens.... and yet the subject was blurred. It turned out that 4 seconds at 400mm was enough to show the effects of the Earth's rotation... causing the stars to streak. Technically, I needed an even longer exposure to capture this properly (or to stack a bunch of shots). But the best Image Stabilizer I've used did a fine job and it still let me down. For indoor shots, an image stabilizer can be very useful. But with a fast lens it's not required (see samples further down).
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EOS M + EF 100-400mmL II - Handheld (Orion Nebula)
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That's the disadvantage of using Image Stabilizer if you're not shooting static subjects. There's no chance in the world I could have caught any of the following shots with f/3.5 using I.S. for a handheld shot:
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32mm - a fast swimming turtle @ f/1.4 with 1/400 sec and ISO 640
32mm - 1/160 sec @ f/2.8 with ISO 1600 - the bats in the distance show how short this exposure was. Any slower and we'd see people blurred. Any wider with the aperture and some people might have ended up out of focus. Any higher with ISO might have introduced more noise. This was also an accurate representation of the lighting in this environment.
32mm - 1/60 second @ f/1.4 with ISO 250 - plasma
32mm - f/1.4 @ 1/320 second + ISO 500
32mm - 1/400 sec (to freeze traffic) @ f/2.8 for overall DOF clarity and to reduce overexposure with the sunset + ISO 100 to reduce highlight blowout.
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Much bolder Bokeh:
Another important consideration is that the EF-M 32mm f/1.4 STM lens was given a bright aperture to enable useful bokeh. So having set your 15-45mm lens to approximately 32mm, you'd end up with an aperture of around f/5.6-6.3.
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32mm @ f/1.4 - @ f/1.4 + ISO 320 - Marzipan Cake
32mm @ f/1.4 - @ f/1.4 + ISO 200 - Marzipan Cake
32mm @ f/1.4 with 1/60 sec. Handheld and razor sharp with ISO 500 & no visible noise.
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Faster, more accurate Auto Focus.
Another major benefit with using brighter lenses with larger apertures is that the camera's sensor is presented with far more light. This results in faster and more accurate Auto Focus. Even with the Aperture set to a narrower size, the sensor still has the benefit of more light when the exposure takes place. The same applies with using darkened filters like Circular Polarizers and Neutral Density filters. It's one of those things that gets overlooked quite often. And it's one of the most compelling reasons to be using fast lenses.
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32mm - accurate AF through glass in a very dark museum. Tack Sharp @ 1/80 sec with ISO 100. Taken at the Sydney Powerhouse Museum... so dark that I can't even use a PowerShot camera in this room.
32mm - Autofocus in the dark - natural lighting - 1/25 sec (NR applied). I was perched against the door of my car for this shot... with my wife complaining it was
32mm - Autofocus in the dark - natural lighting at 1/80 sec (NR applied).
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Regards,
Marco Nero.
