Images completely white?

[ACC]

Hi

This is odd. I’m wondering if anyone has ideas as to what happened. Canon 600D, 200 shots taken on holiday. Amongst them about 40 where the image created is completely white. All pixels = 255. Either side of the 40 “blanks” are plenty of normal properly exposed images. None of the camera settings were altered. Images were all shot outside in a park on a pleasant sunny day.

 

Anyone seen this before? Any ideas? 

[Niels Quist]

1 hour ago, ACC said:

Hi

This is odd. I’m wondering if anyone has ideas as to what happened. Canon 600D, 200 shots taken on holiday. Amongst them about 40 where the image created is completely white. All pixels = 255. Either side of the 40 “blanks” are plenty of normal properly exposed images. None of the camera settings were altered. Images were all shot outside in a park on a pleasant sunny day.

 

Anyone seen this before? Any ideas? 

 

Don't really know. But if it  happens again I would consider to update the camera software (probably not leave part of the old software, if possible) - a piece of advice I have seen in another forum for this fault (not Canon though).

 

Niels

[wiskerke]

All the same lens: check the aperture.

All on auto: check the aperture.

Different lenses: check the shutter.

 

Set it on manual; look into the lens; adjust the aperture and see if the aperture closes itself quick enough. (Or closes at all.)

 

wim

[M.Chapman]

10 hours ago, ACC said:

Hi

This is odd. I’m wondering if anyone has ideas as to what happened. Canon 600D, 200 shots taken on holiday. Amongst them about 40 where the image created is completely white. All pixels = 255. Either side of the 40 “blanks” are plenty of normal properly exposed images. None of the camera settings were altered. Images were all shot outside in a park on a pleasant sunny day.

 

Anyone seen this before? Any ideas? 

 

Check the image EXIF data to see if it gives any clues?

 

Mark

[ACC]

Hi thanks all for suggestions. Can’t see any problems with lens, shutter or EXIF. Next step = upgrade the software.

[wiskerke]

Was it all with one lens?

 

wim

[ACC]

Hi Wim yes all the one lens.

[wiskerke]

Than the first suspect is still that lens. Has it been too hot at some point? Oil on the aperture blades and that sort of thing?

Has it had a blow?

My guess: it's only when you choose a small aperture and the blades either close too slowly or they don't close at all.

If it's dirty blades the effect will be less outspoken when the shutter time is longer and/or the aperture is wider.

If the aperture doesn't close at all, it's really easy to spot by putting the body on manual. If they only close halfway or unevenly, it has usually had a shock or blow.

 

Software (firmware): usually only with a newer (never experienced that with Canon) or third party lens.

Body failure like dirty contacts: all images would be affected.

With Canon there are no mechanical functions in the body. And while  electronics can fail, it's usually the same for all images. (At least for those shot in the same way.)

 

wim

[Chuck Nacke]

Don't know if this is still true with Canon AF bodies, but back in the days of FD mount Canons, if you had the Depth of Field Preview button pressed or

locked on and you changed lenses the lens you mounted would not stop down.  That drove me crazy back in my days of F-1's

[ACC]

17 hours ago, wiskerke said:

Than the first suspect is still that lens. Has it been too hot at some point? Oil on the aperture blades and that sort of thing?

Has it had a blow?

My guess: it's only when you choose a small aperture and the blades either close too slowly or they don't close at all.

If it's dirty blades the effect will be less outspoken when the shutter time is longer and/or the aperture is wider.

If the aperture doesn't close at all, it's really easy to spot by putting the body on manual. If they only close halfway or unevenly, it has usually had a shock or blow.

 

Software (firmware): usually only with a newer (never experienced that with Canon) or third party lens.

Body failure like dirty contacts: all images would be affected.

With Canon there are no mechanical functions in the body. And while  electronics can fail, it's usually the same for all images. (At least for those shot in the same way.)

 

wim

 

It was a hot day. 29 degrees and we’d walked for a couple of hours. My daughter had the camera on a neck strap so it was completely exposed to the heat. Are you thinking the heat caused the aperture blades to stick then after a while they spontaneously unstuck? I’ve had the camera on manual and a range of apertures while i look into the lens. There’s no sticking or failure to close that I can detect. Should I get the lens serviced/ cleaned?

[M.Chapman]

58 minutes ago, ACC said:

 

It was a hot day. 29 degrees and we’d walked for a couple of hours. My daughter had the camera on a neck strap so it was completely exposed to the heat. Are you thinking the heat caused the aperture blades to stick then after a while they spontaneously unstuck? I’ve had the camera on manual and a range of apertures while i look into the lens. There’s no sticking or failure to close that I can detect. Should I get the lens serviced/ cleaned?

 

Why not inspect the EXIF data to check what the aperture the camera was trying to set during the offending exposures? If they were wide open (max aperture) or only a few stops from wide open, then sticking aperture blades won't be to blame. Indeed, given that you say all the pixels are 255 I struggle to believe that it's sticking aperture blades. Suggest also checking the time stamps on the faulty images. Were they taken as a burst? Are the shutter speed and aperture values on the faulty images sensible or crazy? etc. If the images are RAW files then try developing in LR or whatever you usually use? Is the RAW data white too or just the embedded jpg?

 

Mark

[wiskerke]

1 hour ago, ACC said:

 

It was a hot day. 29 degrees and we’d walked for a couple of hours. My daughter had the camera on a neck strap so it was completely exposed to the heat. Are you thinking the heat caused the aperture blades to stick then after a while they spontaneously unstuck? I’ve had the camera on manual and a range of apertures while i look into the lens. There’s no sticking or failure to close that I can detect. Should I get the lens serviced/ cleaned?

 

29 degrees is not hot. However if your camera was in your car for an hour or so on that day, that may well have been too hot.

It's generally not a problem that heals itself.

As Mark says, examine the exifs for the solution.

 

wim

[ACC]

EXIF shows ISO 6400 f5.6 and shutter speed 1/13. Not a burst but pictures taken over the course of a few minutes. They were the first shots of the day. I guess at those settings on a bright day the images just burnt out. Next step = interview my young daughter to see if she can remember why she had taken the camera off auto and what did she think she was doing with an ISO 6400 setting and also what caused her to switch back. The shots following the blanks are fine and all at ISO 100. 

 

Thanks for all the comments.

[spacecadet]

Only about 12 stops over then

Or possibly would have helped.

I wonder if you've found a menu setting that's prone to finger trouble. I found one for WB last year. Everything ended up brown.

[Patrick Cooper]

On 5/9/2018 at 11:08, Chuck Nacke said:

Don't know if this is still true with Canon AF bodies, but back in the days of FD mount Canons, if you had the Depth of Field Preview button pressed or

locked on and you changed lenses the lens you mounted would not stop down.  That drove me crazy back in my days of F-1's

 

That happened a few times with my Canon AE1 (while exposing slide film.) Though I'm sure I didn't have the Depth of Field Preview button pressed so I don't know what caused it. I also had a Canon A1 for a short time and the internal light meter developed a fault, causing extreme overexposure. I couldn't believe the meter readings I got at a rodeo on a sunny day with the A1. I thought surely this can't be right but foolishly I placed my trust in the meter. As a consequence, my rodeo images were ruined.

[Chuck Nacke]

Patrick,

 

It is pretty simple, on a bright sunny day at 100 ISO the exposure is 250 between 5.6 and 8.  I spent decades using Leica's with no built in meter and

you learn to make exposures or at least know when your built in meter is not working.  the AE1 was not one of Canon's best efforts.  I only used

the F-1s and latter the T-90's which were great bodies.

[spacecadet]

3 hours ago, Chuck Nacke said:

Patrick,

 

It is pretty simple, on a bright sunny day at 100 ISO the exposure is 250 between 5.6 and 8.  I spent decades using Leica's with no built in meter and

you learn to make exposures or at least know when your built in meter is not working.  the AE1 was not one of Canon's best efforts.  I only used

the F-1s and latter the T-90's which were great bodies.

Surely it's sunny 16 (at 125th)? Shutter speed the reciprocal of the ISO rating. So 8-11 at 250th. That's what it used to say on the inside of film boxes.

[Chuck Nacke]

20+ years of RDP inside of Leica M's set at 250 at between 5.6 and 8 in California, Israel, France, Russia and China worked for me....

[Chuck Nacke]

OK, yea I did bracket on occation.....

[Patrick Cooper]

On 21/05/2018 at 14:49, Chuck Nacke said:

Patrick,

 

It is pretty simple, on a bright sunny day at 100 ISO the exposure is 250 between 5.6 and 8.

 

Sorry for replying to such an old post but I didn't realise that you had replied to mine. I knew from experience that the light readings I got from the Canon A1 on that particular day didn't seem right. The camera was suggesting aperture values considerably larger than what I would have expected. To be honest, I was expecting a much smaller aperture setting to be indicated. And by the way, I was reading from a mid tone, not dark coloured subject matter. But I had never owned a camera with a defective meter before. So although the readings seemed really wrong to me and illogical, I was so used to trusting the meter and not questioning it - especially when aiming it at a mid tone. In hindsight, I should have trusted my instincts and knowledge, not the camera meter.