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-   -   XL1 / XL1S focus hunting backfocus problems (https://www.dvinfo.net/forum/canon-xl1s-xl1-watchdog/31-xl1-xl1s-focus-hunting-backfocus-problems.html)

Don Palomaki April 15th, 2002 02:41 PM

Actually the front glass of the XL1's 16x lens is not a focusing element, it is a piece of flat optical glass that protects the Variable Angle Prism (VAP). The first piece of lens (in the traditional sense) is on the other side of the VAP. So dust on the front glass is actualy some distance from the first element of the lens, and at a small f-stop is nearly within the depth of field range.

A problem with 'less than an inch' shooting in macro range is lighting the subject. THe lens casts a big shadow.

ja135321 April 15th, 2002 05:41 PM

my bad luck
 
I just received my 3x wide angle lens today and I look at the glass that connected to the camera and there is a DUST particle on it. I try to clean it and realize its on the inside of the lens. What are those Canon QA or QC guys doing?!?! I say oh well its just a spec. So I put it on the camera to check it out. There is a blur on the image. I check the paper that the lens comes with. It says the depth of field is greater than that of previous video lenses and any dirt or dust on the surface of the lens will be projected. I wish for once something would go right.

Anyway if anyone is planning to buy the VL-10li (Canon Camera Light), dont bother its a waste of money. You could mount a maglite on the camera that would do a better job that this light. Its like hunting for deer at night with a big spot light. If anyone wants to buy it, I'm selling it for 70 bucks. Never been used cept once for about 30 seconds.

Chris Hurd April 15th, 2002 06:10 PM

Send your 3x back to whoever you bought it from and get that situation resolved. Post your VL10i for sale in the classified section -- sorry you bought that thing; if you had asked me first, I would've talked you out of it! ;-)

Jeff Donald April 15th, 2002 06:50 PM

It's not uncommon for specs of dust to be inside of a lens. They are not sealed totally against dust and moisture. The lens gets (or the box it's in) dropped a few times and some dust gets dislodged. If the spec is showing up in your picture send it back like Chris says.

Jeff Donald

Don Parrish June 1st, 2002 07:29 PM

Lens, Focus, technique, bad day
 
Got a chance to shoot for a network morning show, I was asked to shoot some footage of a re-election speech. It was hot!!! humidity was probably bad, but no indication of a moisture problem. XL1S 16x II lens, nd filter on and polarizing filter, shooting in manual / AF manual. 1/90th sec. F3.7 I should have positioned myself with a larger F-stop. This was not a learning situation. The main guest arrived on a bus and walked 200 yds down the middle of the street in a 10 ft wide path made of plastic chain, people on both sides shaking his hand, I have always been able to zoom in on people and use the push to focus button, but not today, even manually focusing, the subject just looked slightly blurry unless he filled the EVF, dark shirt, no vertical lines, usually salt and pepper hair zoomed in close does the trick, problem was this man was constantly moving, back focusing did not seem appropriate, nothing was close behind him, I was actually having to battle (inside this 10 ft swath) with 2 other camera men one with a reporter, 3 still photogs, and for some reason 2 men with pad and paper, plus security, aids and so on. Everyone with cameras was stepping in front of me as I shot. Security said to stay 20 feet away, I did, others didn't. When I had an open shot on the subject I had to be fast, I did a fair job on the shoot but missed a lot of opportunities. Why would one subject look slightly out of focus so often, Also, previous to my battle I was shooting crowd shots and noticed that when I was focused on something in the shade and panned out of it into the sunlight, the shot would be overexposed just for a split second until it appeared something automatic kicked in and changed the exposure value. I was in manual? Questions - depth of field, always talked about in photography, using aperture on the xl1s, does it effect depth of field? Why can't I create a large focused area using larger # F-stops? Focusing once and trying to stay the same distance away did not help, depth of field most have been six inches. How much of the viewing area is used to push-focus and is it in the middle. How would you approach this shoot. No area or platform assigned to media. ( assignment editor wanted street level shots). walking backwards and continuously filming did not look even remotely pro so I abandoned it early.
Thanks
Donny

K. Forman June 2nd, 2002 07:28 AM

Maybe put the lens over your shoulder, flip the viewfinder over, and walk foward while taping behind you? Just a thought...
Keith

Bill Ravens June 2nd, 2002 07:34 AM

DOF is, most certainly, available from any lens with an adjustable aperture, including your eye(a well known technique to improve your performance on an eye chart). Unfortunately, DOF effects are diminished for smaller diameter optics, such as the Canon lenses designed for a 1/3 inch focal plane....ie they're not nearly as noticeable as for a 35mm focal plane lens.

IOW, depth of field increases with increasing numerical aperture until you reach the diffraction limit, which is around f/32 on the Canon 16x zoom lens.This shoot sounds like an opportunity for a monopod and guerilla tactics.

Michel Brewer June 5th, 2002 11:07 PM

bad day....
 
just a few thoughts, the advanceperson/press aide is your friend youre the one shooting for a network their candidate wants to be featured on have them lay everything out get as much info as possible and be prepared for it all to change. When the others ignored security you go with them......(as long as its not secret service) did you have a press badge?

as for going backwords unfortunately its the reality of that type of speech the other is walking alongside but in 10 feet of space wont happen, and walking backwords without a guide (producer/tech) watching out for you isnt easy, theres been many camera guys taking hard falls even the ones who do it every day.

If they didnt have a spot for the press pick the best you can..... setting up next to the others dosent really work, neither does a press area/podium always become the best spot. The problem is they generally are shooting large cams with doublers and other nice toys...they can get shots youre never going to get.

Another idea rent a small cam a pd100-150 with a w/a, good shotgun and use that for run and gun, they can be very forgiving the lcd is what youre looking at lots of flexibility and if its outside daylight your good just leave it in auto.......

and lastly if you get at least a few minutes of good video, feed that first so they see it right away, they will be happy therye only using 40 second of it tops

Don Parrish June 6th, 2002 04:42 AM

Thanks, yes I had a press badge, I tried to get in touch with his staff but the assignment editor called me 18 hours before the shoot. The other problem was that this occurred in The Villages Florida which has their own TV and Newspaper and they were kind of given free run. At one point the villages event coordinator told 3 of us to stay back while the Villages media was allowed to swarm the guy. Not fair but one of those get over it things, They own their own community for 30 square miles or so. In thinking about it the last few days (hindsight is good stuff huh?) a second camera may have been the solution, also, subconsciously, I may have thrown 2 elbows into ribs and stepped on one ankle. If I did do that, It would have been unprofessional, I think? I also would have thought any media would have been briefed and press badges checked? I actually tried to find a press area but was unable to locate it after asking event people and law enforcement.

Don Parrish July 16th, 2002 07:31 AM

Hocus Pocus focus
 
Either I am crazy or my XL1S is changing focus occaisionally when I am in manual. I always use my camera in manual focus and use the push to focus or the focus ring. Is anyone else out there seeing this or am I loosing it. It is a very short burst of movement but substantial enough to see. Focus does not change during a shoot it usually happens within a second after I have "push to focus" or else it is happening when I use the focus ring, I am not sure which.
Thanks

Rik Sanchez July 16th, 2002 07:55 PM

With the standard lens (16X) that comes with the camera, it's not a real manual lens in manual mode, it still uses its servo motors to focus the lens even though you turn the focus ring manually.

I hate it when I zoom in on something and focus and then want to zoom out, sometimes the focus will shift drastically out of focus and I have to shoot it again, and that's with me not touching the focus ring, I'm just turning the zoom ring. I can usually get it in 3 takes.

The only way to get total focus control is to get the manual lens, then you can focus in and it will hold the focus.

Don Parrish July 16th, 2002 08:09 PM

I should have been able to figure that out but apparently I didn't, thanks. That also explains why people talk so much about the manual lens and also the reason why there are no stops on the focus. I think I want to add a manual lens to my gear. But do you have an occaisional inadvertent movement from the servo from the 16X lens or is it not maintaining focus throughout the zoom??

Rik Sanchez July 16th, 2002 08:31 PM

One day I'll get a manual lens, I also hate the noise the servos make when I zoom, I can hear it sometimes. But it only goes out of focus sometimes, it seems to sense I'm doing a critical focus shot and it will act up, but for the most part, it behaves itself. It's only lost the focus on a zoom a couple of times.

I've also been able to get some nice foreground in focus/background out of focus shots with that lens, I'm sure I will have more control with a true manual lens.

Don Parrish July 16th, 2002 08:40 PM

I guess I am either lucky or deaf. I have never heard servo noise in either live or recorded situations. I also don't tighten the screw down on the boom mic very hard, just enough to hold it in place. If I ever get the manual lens I would have to spring for a better EVF or LCD. I would love to be able to see sharp focus on my XL1S.

Rik Sanchez July 16th, 2002 08:53 PM

I just posted something about the viewfinder in another post, but I have the older XL-1 and I borrowed a friend's XL-1s while mine was in the shop. The first thing I noticed is I had a harder time focusing with his camera, with mine I can get the focus very easily, it took more effort with his XL-1s, I wonder if the viewfinders are a little different. Another thing is my focus ring is turns alot easier than his. Do the new lens have a slightly different feel than the old lens or is it just me?

Would hooking up a small monitor and turning down the color to make it B/W help with the focusing?

I remember with my very, very old Sony VX-1, it had a B/W viewfinder and focusing was great with it.


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