I just wrote an email to Cinetech:

"Are there any limitations, that I should know about, using the Cinetech Follow-Focus with my 16x servo lens? Like the Follow-Focus system is not designed to just make focusing "easier", is it?

I'm asking, because I find it hard to believe that a mechanical focusing system can get around the spongy speed sensitive servo focusing ring of the Canon 16x!

Just to make sure I'm getting this right, once I have set marks with the Cinetech Follow-Focus system, I will be able to consistently dial to these marks repeatedly, regardless of the dialing speed? If the answer to this is yes, I don't suppose you would explain how this is achieved?

I'm sorry for being so skeptical, and I don't expect you to divulge any trade secrets. But I don't believe that what I have just suggested is possible with a simply mechanical device. Maybe you can convince me that the FF overrides the speed sensitivity of the servo lens, without us having to go through the hassle of an international parcel post demo. Or do you have a Rep. here in Germany, where I could try out the system?"

I'll let you know how they respond.

The experiment
Can the Canon 20x auto lens repeatedly and accurately hit preset focus marks?

The equipment
Canon XL2 w/20x auto lens, 16x manual lens, FU-1000 B&W viewfinder, mounted on Vinten Vision 3 head on Vision Tripod. Chrosziel bracket and rod holders, Cine Tech Titanium SL follow focus unit w/ coarse and fine pitch drive gears, coarse pitch gear ring for 20x auto lens. The 16x manual lens was used as the control lens. A matte box was not required for this experiment, so stock lens shades were used.

Settings
Aperture-f/2.2. Focal length-48mm*. Near focus point-11' 5.5". Far point-27' 11". Distances measured with a Stanley 100' steel tape and anchoring off the metal block that holds the rods on my Chrosziel matte box bracket. This approximate CCD location is based upon WAG. High contrast marks were used.
Notes:f/2.2 is maximum aperture at 48mm on the 20x lens. *Focal length was determined using the 16x manual lens and then making framing marks for the 20x. Camera aspect ratio set to 16x9, in manual.

Results Summary
Question: Can the Canon 20x auto lens accurately and repeatedly hit preset focus marks?
Answer: Yes and no
Explanation: If you set your marks and do not go beyond them, or change the zoom, you should be able to get repeatable results. Focus speed does seem to have some effect in making the marks drift. I was doing rather small pulls approximately sixteen feet between the near and far marks. The marks on the disc were about 3/8" apart, so I couldn't really zip between the two very quickly, without overshooting the mark.

I then zoomed wide and adjusted the focus, quickly going back and forth close and far distances a few times with the focus knob. The marks were obliterated by doing this and I had to reset the focus marks. Zooming shifted the marks also. This means that you cannot zoom in, get critical focus and then zoom back out to your shooting focal length. I did this, zooming in focusing and then zooming back out and the marks shifted significantly.

Shutting off the camera and then powering up again several times did not affect the focus marks. On powering up the focus mark that the camera was set to was sharp and shifting focus using the preset marks on the follow focus disc were accurate.

Daniel, as part of the thread that this came from I have made a new thread with the results of my research on follow focus with the 20x auto lens.

"Canon 20x auto lens follow focus accuracy"
http://www.dvinfo.net/conf/showthread.php?s=&threadid=38166

This new thread you've started is good since I don't really know how the 20x auto lens works. Someone suggested that the firmware in the lens could be updated. This would be good because hard stops and footage/meter scales could be programmed in as well as a way to figure out what focal length you're at.

Can anyone hack the 20x?

Thanks Mark,

You have confirmed what I suspected. Too bad, I would have love to have had the possibility of snap-to accurate focus, along with the image stabilizing of the auto lenses. I like to do a lot of hand held tele shooting. I guess you can't always have your cake and eat it at the same time.

Your little test here, has burst a tiny bubble of hope, but it has saved me a lot of time and trouble getting it to burst on my own.

Thanks again.

Daniel: I'm wondering how you are going to do focus pulling and
do hand held shooting at the same time. Why not get the manual
lens to do the focus pulling when you need to (you should not
need OIS in this case anyway) and use the OIS lens when you
are going hand held.

Hi Rob,

I have found the image stabilizer on the 16x servo lens to be so good that my preferred method of shooting is with the lens very telephoto, and the camera braced under my arm. I'm not really only interested in focus pulls, I would like to be able to focus the servo lens consistently and be able to use techniques like judging the distance to the subject. What I would really like is a manual lens with the servo's image stabilization. But if there were such a thing, it would probably be out of my price class.

As to using a follow focus hand held, I'll admit that it is somewhat awkward, and you sweat a lot, but it is possible. And I have gotten good results shooting like this, with, and without an assistent. There are some prime lenses that are so stiff, you can only focus them with an arm or a FF.

Cheers,

So if you are handheld in low mode I assume you are in a wide
angle shot? Do you really need that critical focus then? (since
your DoF should be pretty large)....

I like to shoot with a long focal length in this mode. Because I really like the look of the shallow DOF. Shooting from the hip like this also allows me to add a little movement to the camera and adjust to how the person or persons I am filming move. Without the stabilizer, I wouldn't be able to do this with half the focal length. I'm not into dogma style shaky camera work.

I'm not up much on filters at the moment, and need to find out what kind of filter I need to buy to protect my 20X lens from getting marked or scratched. I don;t want a filter that will minipulate the image, mainly for protection. Someone told me that it might be called a UV filter or Daylight filter? and would it be suitable for both interior and exterior shooting?
Thanks ahead of time.

<<<-- Originally posted by Joseph Andolina : what kind of filter I need to buy to protect my 20X -->>>

Most likely Canon has a 72 mm filter called "Protect" as an accessory to the EF-series lenses. That should be a neutral glass and that should fit to the 20x lens. Ask some Canon rep./dealer about such filters. (I have myself a Canon 77mm Protect "filter", and pretty sure the same exists in other size.)

Be extra careful and get a very high quality coated filter. I have had a direct light source sneak in past the lens hood and hit the front lens element. Not that big of a deal normally. But with a UV filter on the illuminated lens now reflected back at itself on the back of the UV filter. So now I have a shot of the talent and half of it is obscured by a reflection of the lens! Now....it was transparent but as I panned and moved you could clearly see that there was something in the frame screwing up the clarity.

You will find a few guys on this board who swear that you should not put any extra glass in front of your lens unless absolutely necessary. I believe Charles Papert is one of them and he is a highly respected DP if I am not mistaken. So he knows a thing or 2 about optics and quality.

Personally I agree with him and only use filters for effects or to protect the lens when in some extreme environment like the beach, desert or a pit full of scorpions.

thanks guys for the advice. I just called Glaziers in Seattle, and they do have the UV filter I guess I can purchase. I will be using it with discretion, depending on the environment like you said Marty, but will be doing tests with it on to see if I do notice any problems. More than likely I wouldn't even have it on if I'm doing interview shots inside somewhere.

<<<-- Originally posted by Marty Hudzik :
Personally I agree with him and only use filters for effects or to protect the lens when in some extreme environment like the beach, desert or a pit full of scorpions. -->>>

The latter of which is typically a daily occurance for my filming needs.

Joseph,
You mainly need to look for this issue when there is a light source in the frame (or just outside of it) that causes lens flares. It is possible that the light can creep in, not cause a flare but still reflect back. I used with a UV on there for 6 months and had no problems but then one shoot the sun was in just the right spot and wham! Ruined my shot! Nothing like having a ghost image of a transparent semicircle in the bottom half of the frame! The lenshood was shading the top half of the lens for me.

Oh!!! If you are using a professional Matte Box this issue may not occur at all or only when the light source is in the frame. Good Luck!

The main problem I've noticed with them is when there is light from the front or side I'll often see a spot from where water has dried and left mineral residue. The bad news is the picture is not as nice as it might be without the spot. The good news is that the spot is on the filter - not the front element of the lens.

Question: The 20X has elements which are coated with calcium fluoride. Is the front element one of these? Is calcium fluoride softer than glass?

Interesting twist (discovered while researching CCD's for another thread): Silicon CCDs are the opposite of film in that they naturally have reduced response to shorter wavelengths and increased response to longer ones. Thus the traditional UV filter isn't doing us any good in terms of haze reduction. An IR filter would be required for that.

Great post Mark. I was wondering this exact thing.

Hi all

just a simple question for those of you that use the zoom and focus presets. I find them very useful for slow crawls where I can remove my hands from the camera.

But anyway, how do people use these features if at all because I find that unless under very controlled situations it's impossible to use these switches on the lens without moving the camera, even on a tripod with some zoom on. Is there any magic tricks or methods to use these switches and not end up with a jerk in the footage when you flick the switch?

Also does anybody find the slow focus speed way too fast when using these features, almost too fast to bother using it to slow focus change from foreground to background? Even then, anytime I've used it I shake the camera making the effort a waste of time. Maybe I'm using it wrong?

Anyway, anybody got any comments?

Donie

Hi all

Anybody use this feature at all? Is it just tripod that is the problem?

Thanks
Donie

Donie - I experience the same problem as you with a jerk in the footage when flicking the switch.
I recently got a better and more stable tripod (Libec T58 with H55 head), and the jerk is not so noticeably as with my first tripod, even if you can still see a small jerk. I think more practice will help me a lot!

- Per Johan

With the preset Focus/Zoom being a slider switch, I think having the camera move when sliding the switch is virtually impossible to avoid. I wish Canon had made the preset a simple push button or even better something you can activate using the remote. Wouldn't that be cool. I use the preset for doing slow pull outs on a golf show, so I get in as tight as the lens will go and just accept that the first 15 or so frames are uselss.

I still see the 1.6 extender from Canon advertised for the x16 lens and am wondering if it also works ok on the 20x lens.

Also, can the century tele lens be used with the 20x lens?

See http://www.dvinfo.net/canonxl2/articles/article10.php#xl20ex

Greg, I use the 1,6 extender with my 20x lense. I am taking lots of wildlife footage. If you would like to take a look at some footage were I use the 1.6 extender, take a look at one of my previous thread at this forum:
http://www.dvinfo.net/conf/showthread.php?s=&threadid=40780


- Per Johan

wrangler note: edited link to make it active -gb-

<<<-- Originally posted by Greg Jacobson : I still see the 1.6 extender from Canon advertised for the x16 lens and am wondering if it also works ok on the 20x lens.

Also, can the century tele lens be used with the 20x lens? -->>>

Thanks, but I guess you can't also use the Century tele lens on the 20x as you can on the 16x?

Also, if you use the EF adapter I would imagine that you could also use the 2x extender for the Canon lenses on the XL2. Right?

Those photos of the tractor are amazing. Nice reach.

I don't see any reason why you could not have both the 1.6x extender plus the Century teleconverter both on at the same time.

Greg, have you seen this? http://www.dvinfo.net/canon/images/images17.php

<<<-- Originally posted by Chris Hurd : I don't see any reason why you could not have both the 1.6x extender plus the Century teleconverter both on at the same time.

Greg, have you seen this? http://www.dvinfo.net/canon/images/images17.php -->>>

sweet :) I was thinking about picking up a 400mm lens. Never have seen one of those beasts in that article.

My beef with still photography is no matter how big a lens you use you still can't really zoom in from far away but with the XL2 and using the same lenses you can see some amazing details.

Is there any other video camera that can use Canon lenses?

For whatever it's worth.....

http://www.surfshooterhawaii.com/clipstream/moon1.html

Aloha,

Terry Reis
Surf Shooter Hawaii
Waikele, Hawaii
http://www.surfshooterhawaii.com

<<<-- Originally posted by Greg Jacobson : <<<-- Originally posted by Chris Hurd : I don't see any reason why you could not have both the 1.6x extender plus the Century teleconverter both on at the same time.

Greg, have you seen this? http://www.dvinfo.net/canon/images/images17.php -->>>

sweet :) I was thinking about picking up a 400mm lens. Never have seen one of those beasts in that article.

My beef with still photography is no matter how big a lens you use you still can't really zoom in from far away but with the XL2 and using the same lenses you can see some amazing details.

Is there any other video camera that can use Canon lenses? -->>>


kewl!

Recently got my new XL2 and when I turn the camera on the lens makes two loud clicking sounds that sound more like pops. Does everybody's 20X lens do this. I thought it was a problem with the image stabilizer, but it seems to work a little bit. Otherwise, great camera, beautiful picture. Glad I founf this messageboard. It has answered a lot of questions. Thanks.

i've had that problem as well, you can see an element sorta jiggle in the lense when it happens, right at start up, after that no problems

I never had that sort of sound. I find the VCR gives off a low clicking noise every 10 seconds for the first 15 minutes of operation but after that is dead silent. My lens is relatively quiet during startup.

Nope, so far I haven't noticed such a sound Scott.

Richard

Yep, I hear 2 loud clicks right when the camera is turned on. Don't know if it's the image stabilizer or not because it still happens when the image stabilizer is off and the camera is powered up. I just assumed it was normal, hope is not a problem.

Ben

No clicks thus far.

Christian

Mine did click, then the zoom would stutter violently. Send it back to B&H for a new one. The newer on does click at start up but all is fine.

Hello Folks...I believe this is a normal response for the 20X lens. Upon turning on the lens, there will be an imgae shift adjust which is quite normal. Do not worry about this. I spoke with Canon rep as well and he confirmed this to be the case. My 20X does the same. Nothing to worry about.

What's that? What's shifting and why?

My guess would be that that is the stabalization mechanism inside the camera, and when it starts up it just has to calibrate or something.

From everyone I have talked to, the shaking is normal, but I cannot defend the clicking noise.

Make sure when you turn that bad boy on, the lens cap should be removed first. Also, make sure that the lens is locked into place. Otherwise, contact your retailer.

-Lon

it's a pretty unnerving click, VERY noticeable almost, i shutter to say, like a plastic gear slipping.

i once rented a panasonic 24p where the focus element was completely loose, you could tilt the camera up and down and try to balance it into focus, obviously it was returned, i'd hate to think it would be something like that

Maybe my experience this past weekend can shed some light on this "clicking" phenomenon. My XL2 did not have the clicking noises on start up when I first got it. Went shooting this past Sunday and noticed a random out of focus black fuzz moving in the viewfinder. Clean out the view finder and lens filter. 20 minutes later and it was back. So I think there is a bug between my filter and the lens. Upon closer inspection, there was a bug inside of the actual 20x lens!!! How he got in there I don't know, but man he I was pissed to say the least. When I put the lens cap on for a few minutes and then take it off, he would not be visible. My guess is without light coming through the lens, he can see the light coming in from wherever he entered and was trying to exit. Anyhow, I shoot through the evening and the next day, no sign of him. So either he got out or died. But around mid day, when coming out of standby, I hear the 2 clicks and immediately remembered this posting. Coincidence, I don't think so. So maybe he gummed up something which is causing the noise. Operationally everything seems fine, but I will be sending it in to Canon the first chance I get.

Kevin

That must be a Dvinfo first. :}

Wow Kevin, that's a new one on me. By the way, is this a beetle of some type. I've heard there is some type of beetles that make a clicking sound. I would 'love' to know how that bug got in there. Ohhhh, I just thought of how...this has to be a Japanese beetle, they are yellow and black IIRC. Obviously it got in there when the lens was assembled. Maybe this is some sort of 'tracking bug' so they can find out where their cameras are being sold.

Sorry, I just couldn't resist. Please keep us posted as to what you find out on this issue.

-gb-

Yes, I contacted Canon and they basically said to not be alarmed. I was told they have employed Banon Beetles to control the auto focus mechanism in the lens (20x only, sorry) and there was a dispute with the union, hence the walkout...

The issue has been resolved, all beetles have returned to work, but click to remind the user to put pressure on Canon for fair pay ;-)

Actually, I'm picturing a gremlin like the one or ones that took apart Bugs Bunny's airplane/bomber.

Has anyone else noticed that it is only the cameras in the US which click? Or at least whose owners are willing to own up to it in this forum.

Hmmmm. My XL2 remains firmly in Europe thank you! ;-)

My 20x clicks. So far, so good. That's prosumer for ya.

I once had a spider make it's home inside my Nikon F3. Imagine my surprise when it appeared in the finder! The F3 is probably Nikon's worst camera, so that's par for the course. Luckily the camera belonged to the newspaper I worked for. I would never pay money for an F3. Yecchh.

That camera was such a piece of ****, I wanted to to just pound it it against the pavement until it was tiny bits of metal, plastic and glass. It never performed well and it synched at 1/90th of a second. What a piece of crap.

You may have had a Korean beetle, so that's a different union. Actually, I'm not sure that the Korean beetles are unionized.

Hey all,

I've recently bought an XL2 and have only just used it for the second time. On my first shoot i didn't notice this problem but today while playing around in my yard i noticed that the lens is really noisy. By this i mean that when i have auto focus switched on all i can hear is your typical still camera auto focus sound clicking on and off. With the onboard mic switched on and using manual levels set to about halfway the sound is audible on the levels monitor.

Also when zooming in and out with the same audio levels I can hear a motorised sound through the mic. Yes these sounds are audible when played back on a television or even through headphones when recording. I'm wondering if this is normal as I feel it may be a problem when filming quiet scenes when i want ambient sound recorded using the onboard mic. Has anyone else had these problems or is the 20x lens just really noisy? As i may be sending the camera back to Canon.

Any help or advice would be really appreciated.
Kind Regards
Harley Heffernan

Would someone owning an XL2 be able to tell me if this is normal and if it happens with their camera? If it's common and normal i won't worry too much. But if a lot of you guys with Xl2's dont have this problem i'll talk to Canon.

Hoping a few people can let me know what their cameras do.
Cheers.

Dear Harley,

Have you worked with an XL1s or XL1?

Zoom noise is normal on these cameras when using the on-board microphone.

This effect can be minimized with the Lightwave System's "System Isolator".

Whenever possible, I use an off-camera microphone, usually with a boom pole.

I have not heard, nor have I searched for, "Auto Focus" noise.

Thanks for your reply Dan.

Yes i have been working with both the XL1 and Xl1s in the past. They were nowhere near as noisy as the XL2. Although i could hear their zooms i never had any problems with the onboard mic picking it up.

I too will be doing the majority of my shooting with wireless lapels and booms but at times may be covering events where i need to use the onboard mic.

The zoom noise i could probably live with but the auto focus noise will drive me crazy and even more so if the mic picks it up while recording.

I hope a few more people can tell me how their Xl2's act but by the sounds of it my lens may be faulty?

Cheers for your reply.