C100: 18-135 STM & your go to lens

S

Scott Freestyle

Well-known member
There is a brilliant write up on Cinema5D by a member called mthomas on this lens. He has a lot of positive things to say about the lens and how well it works with the C100. Anyone else have any experience with the 18-135 stm.. What is your go to lens on the C100..
 
I thought some of you may find this interesting to read!!

mthomas said:
I just wanted to add that the 18-135mm STM lens has really grown on me. I like it, and have used it nearly exclusively through 5 TV commercial shoots last week.


It is NOT a parafocal lens, but since it is a "focus by wire" design, similar to the 85mm f1.2, the lens will automatically adjust the focus to match the point where it was previously when you change the zoom. So I can treat it a bit like a parafocal lens by zooming in to focus on somebody, then pull back the zoom and the subject will often remain in focus. This works smoothly due to the Stepping Motor for the AF which remains actively engaged with the focus group even when the lens is switched to manual focus mode. The stepping motor is much faster than a focus pull and moves quite naturally as it eases into an out of position. I like the way it moves a bit more than the Stepping motor found on my Panasonic Lumix 14-140mm lens which can be a bit robotic when it adjusts for new zoom positions.


Also, as with most non-cine zoom lenses, when you zoom from say, 24mm to 105mm, the physical size of the aperture ring must change to maintain a constant aperture of, say, f5.6. Currently this behavior is one of the primary differences between good cine zooms and still photo zooms.


With a 5Dmk2 or mk3, the physical aperture ring is locked so when you zoom, your exposure will shift with most lenses, often getting darker at the tele end. The only way to override this in manual movie mode on a 5D or similar camera is to bump the aperture up and down during your take after zooming, which is very annoying.


The C100 has a setting in the Menu to enable the camera to continually adjust the physical aperture size as you zoom to keep the brightness somewhat constant. It works, but you do get a slight flash or bump during fast, broad zooms. This effect is noticable at times, and rather annoying on most lenses since it is not very smooth. But it is better with the 18-135mm STM than with most other "Stills" zooms. I've found that with smaller short zooms, even very fast dramatic instant pushes, the exposure adjustment is hardly noticeable. I suppose this is also because the lens is adjusting your focus at the same moment as it adjusts your iris, so you see a slight defocus at the same time as the exposure changes. The exposure and focus adjusting simultaneously looks and feels a tiny bit like a film roll out and feels more organic than either of these alone, and could easily be interpreted by the viewer as a creative intended effect.


Also, I like the 18-135mm focus ring. Since it is focus-by-wire, the ring has very little resistance and is therefore very easy to turn with just the tips of my fingers. With the C100, I like to rest my left hand palm on the excellent ridge that extrudes from the front of the camera. Having the focus ring turn easily with just my finger tips really helps me keep my hand muscles limber and responsive to quick and accurate focusing. Tighter rings may "feel" better if you are gripping the ring with your whole hand, but such focus rings are much harder to turn with your finger tips using this camera holding method I prefer on the C100. With other lenses, I suppose you'll want to add a follow focus and other stabilization riggings to free up your wrist for the additional torque. But the 18-135 STM seems to be much easier to use without follow focus or any other kind of rigging gear since it is easier to turn and consistently accurate. It really does feel like the 85mm f1.2, only with less travel in the focus ring.


Also, I believe the 18mm rating for the lens is an accurate number. Many times with zoom lenses, they are not as wide or tele as the manufacturer says in the lens name. But with this one, I think it really is 18mm at the wide setting. Perhaps this is because the EF-S mount allows for wide lenses to be designed with less trickery than is required with Full Frame lenses. I tested my 16-35mm f2.8 II lens at 16mm and hardly saw any difference in field of view between that and the 18-135mm at the wide setting. There may have been a few degrees difference but nothing like I expected.


The C100 has a setting that allows the camera to slightly crop its imager to an APS-C size rather than the slightly wider Super 35mm size. This is to compensate for some EF-S lenses which don't fully extend their image to the edges of a Super35 sensor. With the lens I have, this mode is unnecessary. My 18-135mm doesn't appear to vignette very much at the corners in Super 35mm mode. This could be because the lens was profiled and designed for video use, or it could be because I am lucky and got a lens copy that gives that extra millimeter of image projection over other EF-S lenses.


Also, my copy of the 18-135 STM is very good optically. It handles flare VERY well when there are backlights, and I have't seen any "Dancing" bokens from the Image Stablizer adjusting during shots which I find very common with other Canon lenses. I would say it's better than my 24-105 F4 in backlights for this reason. And I haven't noticed much distortion at wide settings. I'm sure there is some, but I don't notice it the way I notice it on full frame lenses. It's obviously sharp enough for 1080P and seems to be very well profiled for Canon's excellent Lens Peripheral Correction feature. I haven't even seen any overt cases of Purple Fringing with it yet which I see regularly with many of my other Canon lenses.


I strongly recommend the 18-135mm STM as the main lens to use with the C100 if you can basically keep it at f5.6. Forget what you've known with the 5D, and high ISO shooting: f5.6 zooms are much more useful with the C100 than before.


The C100 looks MUCH better than the 5D at higher ISO's since the colors are not compromised in the way they are on DSLRs. I've found the C100's sensor noise to be so natural and film-like that I can use the camera at ISO 8000 and F5.6 in places where I would have previously believed F2.8 would be absolutely necessary. Sure there is a bit of grain, but it is a nice grain, and the colors and dynamic range remain very similar at high ISO's. Recording ProRes to a Ninja can help preserve this film-like grain and does make a difference in the feel of the footage at high ISO's. This high ISO color fidelity and film-like texture is something the 5D or my FS100 simply can't do. I believe it is due to the way that canon is processing the sensor signal without having to debayer it. This yields a different kind of noise pattern that seems to have finer grain, producing less macro-blocking or banding than typical high ISO footage when it is played back uncompressed. If you are compressing for broadcast, much of this texture will be lost, but in the cinema or over high quality Blu-Ray, it should look very natural.
Click to expand...

Definitely sounds like a lens to have your bag, and its very affordable...
 
Yes its a great lens for specific purposes. I call it my breaking news lens. I used it covering hurricane sandy in NYC, Sandy Hook in Connecticut and the hostage situation in Alabama. When you cannot change lenses this one wins hands down. I have the 17-55, 10-22, 70-200, Zeiss 25, 35, 50, and more but when **** hits the fan there is no question 18-135 is wide enough and tele enough for most hand held situations. This lens has 3 things that work well with the c100: its sharp enough, the IS is incredible: you can handhold at 135mm, the AF is extremely fast and accurate i only use PUSH- AF. Use it outdoors at F5.6 or 8.
 
I want to resurrect this thread as I've seen a couple of questions about the 24-105 recently and I think there is a better alternative. I just picked up the 18-135 STM and it is a revelation for me. For events, I always considered the 24-105 to be the best because of its extended range and the IS. Its main problem was that at anything above f/4, it acted like a variable aperture lens. As I've discovered, at anything above f/4, the 18-135 is a better lens for most uses. First, if you set it at f/5.6, it will actually hold it's brightness throughout the zoom range. Second, it has a better IS system due to the hybrid IS. Third, it has a better range. Fourth, it's electronic focus causes it to maintain focus throughout the zoom range even though it isn't technically parfocal. Fifth, it is dead quiet when the IS is on. Sixth, both the zoom and the focus and can be adjusted with a single finger without effort. Seventh, it's cheap.

It's main disadvantages are that it is cheap and doesn't have weather sealing. It will require peripheral illumination to overcome being an ef-s lens. The footage definitely cannot be used while zooming as both the iris and focus do not compensate quick enough and the footage gets messy. It's not f/4 at the long end.
 
You must log in or register to reply here.
Back
Top