Please Help Me Out, I Am In Pain!!!!!

Dear all, first of all, excuse me 'cause of my english, is not my first language...anyway, i bought a gorgeus Canon a month ago, but i have a massive problem when zooming in and out in, low light conditions.
It seems like i have four shadows on the for corners of the screen and when zooming in, they get darker and bigger around the subject, and of course, when zooming out, they get lighter and smaller and you can see the subject better.
Again, it does only occur when in low light conditions.

It's quite a nasty effect (perhaps defect) ....

I am a newbie here, but believe me your help will be much appreciated, because this is not good at all for £2.3k camera, i have my panasonic Nvds-150 and despite my Canon offers me far better quality, the pana. does not have this zooming problem.

Thanks for all your help.

Cesar

[Rob Lohman]

Please tell us a bit more about the configuration / settings:

- PAL / NTSC
- Normal mode / Frame mode
- Changed any of the settings like sharpness etc?
- which recording mode where you in? (easy / green mode?)
- What gain / shutter / iris settings where you using if
you where in manual mode?
- White balance setting?
- What did the internal light meter say?
- On what are you watching your footage? TV? Computer?

etc.

Thanks Rob....

PAL

Both modes

Yes i did change it, i was using that setting with 0 sharpness
easy

-3db , i can remember the other ones

yes i was shoting in manual mode

internal light meter...i do apologise, does it have one ?

both computer and a TV monitor, i can see the problem clearer, of course, in the TV monitor.

I am not an expert Rob, but all i want is your help now, i know i am being a bit dramatic here, but tell me who can be in peace with a lens that behaves funny in low light.

Perhaps, if you want me to, i can test my camera and get a proper report of the problem with a proper list of the settings used when the shot was made.

Thanks a lot for your help...

[Bill Ravens]

sure sounds like a vignetting problem to me. what have you got screwed into the front of the lens?

Hi Bill, nothing......i have my lens as it came......no accesories at all.
I am sorry for the question, but would you please let me know what vignetting is or is caused for?

Thanks a lot once again

[Bill Ravens]

vignetting is what happens when an aperture that is smaller than the lens aperture is placed in the optical path. For example, if a filter was screwed into the front of the lens that was smaller than the lens field of view. The net result is a blurry shadow in the corners of your image. Unlike your situation, however, this kind of shadow gets better as you zoom in(because the field of view gets narrower as you zoom).

I still think your problem sounds like something is interfereing with the proper delivery of the light rays to your camera sensor.

Hi Bill, thanks for your help, do you recommend me to keep testing my camera or should i call Canon and see what happens.
Ta

Cesar

[Chris Hurd]

I think your best course of action is to record the problem on a DV tape, review it to determine that it can be seen clearly, then take the tape and camera back to your dealer or directly to Canon Servce. I'm not sure of the address of Canon Service there in the UK but there definitely is one in the UK. Good luck,

[Barry Goyette]

I think I've seen the issue you've described. But it is really subtle...I just went and tested it in my studio...only noticeable when zooming very quickly in poor light at f2.8 or lower and is most noticeable against a neutral (consistant) backgrounds. The effect can be seen in brighter light at f2.8 as well, but I think that it is being magnified in lower light by increased gain in the camera. It get's darker as you reach the end of the zoom, because the maximum aperture is slightly smaller at full zoom than it is at its wider settings.

I don't really think what I am seeing is a defect in the lens. I think it a limitation of the design of the zoom that is being enhanced by the extreme conditions. Zoom lenses are essentially big compromises by design, and involve incredibly complex engineering to maintain sharpness and evenness of illumination throughout their range. You've found (one of) this lens's weak spots. As a still photographer for 20 years, I've always always avoided the marginal f stops on any lens (maximum and minimum apertures)...and I think that practice is many times more important with a zoom

My experience with the xl1s so far has taught me that working in low light degrades the image in a lot of ways that I never seemed to notice in a consumer level camera (like my gl1). Yet when well lit, the xl1 provides a substantially cleaner image than any other camera I have used.

[Jeff Donald]

I too, maybe, have seen this effect in very low light levels. This was in a poorly lit family room and not on a well lit scene or outdoors. The lens was wide open and the gain was at max. I attributed the effect to the lens being wide open. If the dealer has another lens you can try, maybe test another lens before sending the camera in. This would also let the dealer see the problem. The swapping of lenses might solve the problem. Good luck.

Jeff