C100: Canon 24-105 is a Horrible Documentary Lens in Very Low Light

I would recommend doing the test that I did before sending it out for service. Find a flatly lit wall, defocus your image, turn on WFM + Spot and compare 24mm to 105mm in the waveform. If the center of the frame goes down on the WFM's IRE scale, I'd be more inclined to get a white box replacement than sending it in for service. These 24-105's are nearly cheap enough to be disposable if you grab the white box deals on Ebay and the like.
 
Well hey, what do you know, I was wrong. Must have not done it with spot turned on last time. There you have it.
 
I back up Cowpunk. I have most of the zooms and all of them maintain the same light transmission when wide open. And all of them lose light zooming in except for the 70-200. Of course, maybe I just got the good copies. It's a PITA, though, because it only makes the L zooms useful for coverage if you keep them wide open. Therefore, I've learned that if I want shoot at less than f/5.6, it's better to throw on the 18-135 STM. With the camera set to compensate for the aperture while zooming, that lens doesn't actually lose light. Plus, the STM motor maintains the focus. While your zooming, everything goes dark and out of focus, But once you stop zooming, the lens readjusts. Better than the L lenses. Your footage is unuseable while doing a zooming, but I shoot and edit around zooms anyway.
 
For what it's worth, DxOmark also shows a pretty flat T-line over the focal lenghts. Follow the link and check 'transmission'.

Unfortunately, it's closer to 5.6 than 4.0, but that's another story. The loss of light is pretty small.

At the end of the day, what matters is your experience. It's hard to beat own tests to get a feel for the aesthetic.
 
I can confirm that the 24-105 doesn't lose a transmission at F4, however it does at all other apertures.
 
I've never heard the expression "White Box Replacement". Please clarify. If I buy a product that is a bummer I tend not to give that manufacturer another chance at my wallet. If this lens is defective I won't replace it with another.

Probably worth another thread but I did notice during editing that when snapped in tele (f4, ISO 2000, 24P) it is DEFINITELY softer than the rest of the barrel. I suppose this revelation is the dif between judging things on location vs in editing on a 27" iMac.

Lastly, anything written in literature by the manufacturer in terms of specs I disregard unless it is something non-fudgable, such as dimensions or weight. I'm not saying they lie but they will fudge.

Extra lastly, I will do the white wall test but not on spot, I want it to average because I noticed the drop off of light comes from the edges, almost like a vignette of darkness. I also will do with and without a white wall because I am thinking the brightness of a white wall, versus real world (faces), may have an effect of fooling the scope. I would post some examples but this shoot involved all kids under 18, but there is a tremendous transmission loss at 105mm at f4.

Uber Lastly, I'm an old timer coming from the film and ENG world where buying a zoom lens started at $10K. I realize that we get what we pay for, that this is a $1100 still lens that we're asking it to perform like the old days and that isn't realistic. But as a doc shooter I have to give the editor a tight of my wide shot as quickly as possible without changing lenses so I feel I must research what else is out there. I thought I should stay within the Canon family so the lens will talk well with the cam's electronics but I guess not.

Or, turn down offers to shoot low light level documentaries?
 
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Just did the test wth mine at F4 and it doesn't get darker when zooming in. But, I don't always shoot at F4...often I shoot at 5.6 (the 24-105 at f4 is quite soft at 24-35mm and 105) so the problem is still there. At 5.6 it darkens quite a bit when zooming in.
 
Doug_EX said:
Just did the test wth mine at F4 and it doesn't get darker when zooming in. But, I don't always shoot at F4...often I shoot at 5.6 (the 24-105 at f4 is quite soft at 24-35mm and 105) so the problem is still there. At 5.6 it darkens quite a bit when zooming in.
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Get a variable ND. Leave the aperture at f4 and rotate the ND to desired f-stop equivalent. I use the-

http://www.bhphotovideo.com/c/search?atclk=Brand_B+W&sts=ma&N=4291599900&Ntt=77mm+variable+nd

Expensive but great, and you can stack other B+W filters with no degradation.

https://www.youtube.com/watch?v=TqoHAO-AgMg

Fotga is a well liked cheaper brand. Good video explanation here.
 
nedcam said:
I've never heard the expression "White Box Replacement". Please clarify.
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I think he's referring to the kit lens being sold outside of the kit. When the lens comes with a body as part of a kit it comes in a simpler white box. A lot of people will buy the kit and sell the lens as it can be cheaper than buying just the body.
 
nedcam said:
I will do the white wall test but not on spot, I want it to average because I noticed the drop off of light comes from the edges, almost like a vignette of darkness.
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Well, that might be the answer right there. It isn't "almost like a vignette", it actually IS vignetting. You probably have over 1.5 stops at 105mm. Couple that with the narrow field of view of 105mm…

But vignetting is separate from transmission loss. At least formally. You can hate it just as much, but it's always a good idea to call the devil by the right name.
 
lightstrum said:
Get a variable ND. Leave the aperture at f4 and rotate the ND to desired f-stop equivalent. I use the-

http://www.bhphotovideo.com/c/search?atclk=Brand_B+W&sts=ma&N=4291599900&Ntt=77mm+variable+nd

Expensive but great, and you can stack other B+W filters with no degradation.

https://www.youtube.com/watch?v=TqoHAO-AgMg

Fotga is a well liked cheaper brand. Good video explanation here.
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Why should I do this? At f4 the lens is soft. No variable ND will change that.
 
nedcam said:
Or, turn down offers to shoot low light level documentaries?
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The industry must be really tuff out there if your turning down jobs based on the cost of Canon's cheapest L lens.

Curious, did you buy it new or used? Grey market or USA? Kit lens? I would prefer to see an example of what you are considering "low light level". Only because some folks definition of low light is ACTUALLY more like no light(especially interior event spaces where almost no camera/lens combo can perform). I have never ran into a problem where F4 was not fast enough, though maybe I would have just chosen a faster lens if I knew light was going to be very low. Can't say I've done too many wide/tights in low light though, at least not without changing position, composition and exp settings. Having used my copy for both video and stills(probably a couple thousand images) I have never noticed any type of softening throughout the zoom range.


Low light is prime territory, but sigma's 18-35 is a rare gem even though its reach is limited. Alternately the only fast zoom's for these large sensor cameras cost north of 20k, so I would say the 24-105 is a pretty damn good deal :)
 
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Hey Leo Grey,

I bought the lens new through Abel. I'd call it in the mud, a ballroom that had the least light on and when I arrived and asked if they could turn it up no one knew where, perhaps because it was a Sunday. So I cranked up to around 1600-2000 ISO. I considered turning off the shutter for a little more ummph but figured I'd get bad motion blur since the kids were all bopping around.

On it's wide end at f4 it was OK, enough light, but the issue was, as stated in the original post, is that when I'd do a snap zoom in for the face tight shot, which is very important in touchy feely children's deadly disease fundraiser videos, the faces were too dark to be cuttable without post work to brighten. That's what PO's me, to look at it 27" wide since I usually don't edit. I had an inkling of it while shooting on my DP4, but it was more pronounced in post, I'd say a full stop.

I did have an on board LED light which I only used in emergency. The kids always look right at me if I have it on.

So when I pick up my C100 from repair I will drop off the lens, seems others here don't have a transmission loss at 105mm but maybe they never noticed it unless they were shooting in the mud and then tried to cut it themselves? After all, I never noticed it these last 14 months.
 
Doug_EX said:
Why should I do this? At f4 the lens is soft. No variable ND will change that.
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If your lens is noticeably soft, I would say there is definitely something wrong. Based on all of my tests, the lens out resolves the sensor of the C100 quite a bit, even at the corners.
 
Starting to wonder if my 24-105 suffers from the same issue.

The issue when doing documentary work is you don't always know what the lighting situation is going to be when you arrive somewhere. Shooting interviews is different because you can setup lights, but when run and gunning I've found myself in situations where I just need to crank up the ISO and use Neat Video in post. Right now the 24-105 is all I run with, but I'm looking at other options with a wider aperture. Any suggestions welcome.
 
nedcam said:
Hey Leo Grey,

I bought the lens new through Abel. I'd call it in the mud, a ballroom that had the least light on and when I arrived and asked if they could turn it up no one knew where, perhaps because it was a Sunday. So I cranked up to around 1600-2000 ISO. I considered turning off the shutter for a little more ummph but figured I'd get bad motion blur since the kids were all bopping around.

I always go 360 shutter in lowlight for an extra stop of light. No real noticeable motion blur, nobody has complained, even for broadcast tv.
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