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minox
10-10-2004, 04:50 PM
I bought the A 95 a week ago - handy as I can take it everywhere, yet vignetting seems to be the biggest drawback - whenever there is a white background it shows clearly - Has anybody else the same problem or did I just get a Monday model?
Is there a filter for post porcessing??

Alnath
10-11-2004, 02:46 AM
I have seen someone else on a non camera forum wonder what was up with their A95, the image they showed has some pretty bad Vignetting as well.

minox
10-11-2004, 02:17 PM
Alnath,

did your A 80 ever show any vignetting worth mentioning?
the pictues on your website seem fine...

Alnath
10-11-2004, 02:32 PM
It was noticable from time to time on very bright backgrounds but not to the extent i have seen on the A95

im_dragon
10-11-2004, 06:05 PM
I have taken many pictures with my A95 (99% in Tv mode) under all lighting conditions, with and without flash, at various focal lengths and aperture values, and I haven't seen any evidence of vignetting. You should post the picture data so people can duplicate your shooting condition.

Alnath
10-12-2004, 04:16 AM
Even on this site own review of the A95 it is easily visible

http://www.dcresource.com/reviews/canon/powershot_a95-review/distortion.jpg

im_dragon
10-13-2004, 09:22 AM
Hi,

I have just taken test shots of a white sheet of paper under bright light, with the white filling the entire picture screen. The shots cover all six discreet focal lengths of the A95. No flash. Exposure bracketed to make sure the pictures come out as bright (but not over-exposed) white, instead of 18% gray. Manual focus (can not auto-focus on plain white).

VERDICT: No vignetting whatsoever on non-flash pictures. I only got some vignetting like the picture you posted only when I use flash. That's due to the insufficient coverage of the flash light. It's visible only in wide-angle shots.

minox
10-13-2004, 04:46 PM
Thanks Im dragon,

below is a test shot I did around the house - the vignetting is quite visible on screen - I went to print the same picture today at a shop - no vignetting on the physical print..interesting

I am new to digitsl photography - can I ask you what bracketing exposure means?? I would like to try the same test you did.

Alnath
10-14-2004, 02:39 AM
Hi,

I have just taken test shots of a white sheet of paper under bright light, with the white filling the entire picture screen. The shots cover all six discreet focal lengths of the A95. No flash. Exposure bracketed to make sure the pictures come out as bright (but not over-exposed) white, instead of 18% gray. Manual focus (can not auto-focus on plain white).

VERDICT: No vignetting whatsoever on non-flash pictures. I only got some vignetting like the picture you posted only when I use flash. That's due to the insufficient coverage of the flash light. It's visible only in wide-angle shots.

Not much comfort to those that are suffering from it though.

im_dragon
10-14-2004, 09:33 AM
minox,

Exposure bracketing is to take a number of shots of the same subject with different aperture or shutter-speed values (depending on your shooting condition) to vary the light exposure. Then you can pick the one that has the right brightness.

For bright scenes such as snow landscape, white sand beach, etc. the camera's auto-exposure always makes the picture darker than normal. You'll need to compensate. The A95 has manually-selected exposure compensation that changes the aperture.

im_dragon
10-14-2004, 04:54 PM
Attached is one of the test shots (other shots look similar). I have to reduce the size to 20%, and save in low quality jpeq to keep the file size down to acceptable upload limit.

This is a plot paper shot. It is lighted by a fluorescent lamp. Camera is hand-held, 10-12in away, and at an angle so that it doesn't cast a shadow on the paper. Bottom half is closer to the paper than the top half. That's why it appears slightly brighter. You can duplicate the shooting conditions to see if yours will have any vignetting. Picture data:

File Name
IMG_0017.JPG
Camera Model Name
Canon PowerShot A95
Shooting Date/Time
10/12/2004 6:58:13 PM
Shooting Mode
Shutter Speed Priority AE
Photo Effect Mode
Off
Tv( Shutter Speed )
1/10
Av( Aperture Value )
5.6
Metering Mode
Evaluative
Exposure Compensation
+2
ISO Speed
Auto
Lens
7.8 - 23.4mm
Focal Length
19.3mm
Digital Zoom
None
Image Size
2592x1944
Image Quality
Superfine
Flash
Off
White Balance
Auto
AF Mode
Manual Focus
Color Space
sRGB
File Size
987KB
Drive Mode
Single-frame shooting
Owner's Name

Alnath
10-15-2004, 02:31 AM
Very good but all that proves is you are not getting vignetting and at the minute you are lucky enough to be in a minority. Others are getting it and there is nothing that can be done about it.

minox
10-16-2004, 07:04 AM
Thank you all for your posts! With more testing and trying I somettimes got vignetting and sometimes not - confusing as I don't fully understand why:
img0358 in manual mode, daylight WB, ISO50 at 1/50 and F2.8, img0378 is inTv mode, AWB, ISO50 at 1/50 and F5.6...one has the vignetting badly, the other not...is the key the white balance?
I guess I can either learn to manage the problem or take the camera back and hope to exchange it for one of the minority versions that doesn't have it ...