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I have a Canon A95. Occassionally (and I'm trying to narrow down when)
I take a photo and I get small circular areas which are lighter than the
rest of the area. They remind me of what would happen when painting
watercolors and an area blooms (but it is a perfect circle).

It seems to happen when the flash fires but the subject is too far away
or there are small areas of other sources of light. It also appears to
be worse at 400 ISO.

I'm trying to figure out what is happening in order to avoid the
situation. If I had to make a guess, I'm thinking the shutter speed is
fast (because the flash is firing), but the flash is not bouncing off a
close object so the camera is picking up the light from the flash. Or
if there is a window maybe it is picking up some outfoor light peaking in.

Has anyone else seen this? Does what I suggest sound plausible?

Looking for some advice on the cause.

Thanks,

Steve

Steven Feinstein wrote:
> I have a Canon A95. Occassionally (and I'm trying to narrow down
> when) I take a photo and I get small circular areas which are
> lighter than
> the rest of the area. They remind me of what would happen when
> painting watercolors and an area blooms (but it is a perfect
> circle).
>
> It seems to happen when the flash fires but the subject is too far
> away or there are small areas of other sources of light. It also
> appears to be worse at 400 ISO.
>
> I'm trying to figure out what is happening in order to avoid the
> situation. If I had to make a guess, I'm thinking the shutter speed
> is fast (because the flash is firing), but the flash is not bouncing
> off a close object so the camera is picking up the light from the
> flash. Or if there is a window maybe it is picking up some outfoor
> light
> peaking in.
> Has anyone else seen this? Does what I suggest sound plausible?
>
> Looking for some advice on the cause.
>
It's a mote in the middle distance.

--
Frank ess

Frank ess wrote:
> Steven Feinstein wrote:
>
>> I have a Canon A95. Occassionally (and I'm trying to narrow down
>> when) I take a photo and I get small circular areas which are lighter
>> than
>> the rest of the area. They remind me of what would happen when
>> painting watercolors and an area blooms (but it is a perfect circle).
>>
>> It seems to happen when the flash fires but the subject is too far
>> away or there are small areas of other sources of light. It also
>> appears to be worse at 400 ISO.
>>
>> I'm trying to figure out what is happening in order to avoid the
>> situation. If I had to make a guess, I'm thinking the shutter speed
>> is fast (because the flash is firing), but the flash is not bouncing
>> off a close object so the camera is picking up the light from the
>> flash. Or if there is a window maybe it is picking up some outfoor light
>> peaking in.
>> Has anyone else seen this? Does what I suggest sound plausible?
>>
>> Looking for some advice on the cause.
>>
> It's a mote in the middle distance.
>
Are you saying that the flash is reflecting off of dust? This may be
possible since the last batch were pictures of a person riding a horse
in an indoor arena (on dirt), but the light areas seem pretty big for
dust. As an example, one of the areas I'm looking at is about 1/6th the
height of the picture. Would a reflection off of dust look that large?

Also, if it is a mote, am I limited to not using the flash in dusty areas?

Thanks for your response.

Steven Feinstein wrote:
> Frank ess wrote:
>> Steven Feinstein wrote:
>>
>>> I have a Canon A95. Occassionally (and I'm trying to narrow down
>>> when) I take a photo and I get small circular areas which are
>>> lighter than
>>> the rest of the area. They remind me of what would happen when
>>> painting watercolors and an area blooms (but it is a perfect
>>> circle). It seems to happen when the flash fires but the subject is
>>> too far
>>> away or there are small areas of other sources of light. It also
>>> appears to be worse at 400 ISO.
>>>
>>> I'm trying to figure out what is happening in order to avoid the
>>> situation. If I had to make a guess, I'm thinking the shutter speed
>>> is fast (because the flash is firing), but the flash is not bouncing
>>> off a close object so the camera is picking up the light from the
>>> flash. Or if there is a window maybe it is picking up some outfoor
>>> light peaking in.
>>> Has anyone else seen this? Does what I suggest sound plausible?
>>>
>>> Looking for some advice on the cause.
>>>
>> It's a mote in the middle distance.
>>
> Are you saying that the flash is reflecting off of dust? This may be
> possible since the last batch were pictures of a person riding a horse
> in an indoor arena (on dirt), but the light areas seem pretty big for
> dust. As an example, one of the areas I'm looking at is about 1/6th
> the height of the picture. Would a reflection off of dust look that
> large?
> Also, if it is a mote, am I limited to not using the flash in dusty
> areas?
> Thanks for your response.

It's worse in compact digital cameras because (1) the depth of field is
much greater so that things which would be completely out of focus on
large cameras can be in focus on compact ones (because of the much smaller
sensor and shorter focal length lens) and (2) the axial separation between
flash and lens is less.

Either post-process the image, reduce the dust, or take several pictures
and hope that one is OK.

David

Steven Feinstein wrote:
> I have a Canon A95. Occassionally (and I'm trying to narrow down when)
> I take a photo and I get small circular areas which are lighter than the
> rest of the area. They remind me of what would happen when painting
> watercolors and an area blooms (but it is a perfect circle).
>
> It seems to happen when the flash fires but the subject is too far away
> or there are small areas of other sources of light. It also appears to
> be worse at 400 ISO.
>
> I'm trying to figure out what is happening in order to avoid the
> situation. If I had to make a guess, I'm thinking the shutter speed is
> fast (because the flash is firing), but the flash is not bouncing off a
> close object so the camera is picking up the light from the flash. Or
> if there is a window maybe it is picking up some outfoor light peaking in.
>
> Has anyone else seen this? Does what I suggest sound plausible?
>
> Looking for some advice on the cause.
>
> Thanks,
>
> Steve
Yes. Usually when using flash, in a place where there is dust in the
air. The dust particles will reflect the flash causing this problem.


--
Ron Hunter

Steven Feinstein wrote:
> I have a Canon A95. Occassionally (and I'm trying to narrow down when)
> I take a photo and I get small circular areas which are lighter than the
> rest of the area. They remind me of what would happen when painting
> watercolors and an area blooms (but it is a perfect circle).
>
> It seems to happen when the flash fires but the subject is too far away
> or there are small areas of other sources of light. It also appears to
> be worse at 400 ISO.
>
> I'm trying to figure out what is happening in order to avoid the
> situation. If I had to make a guess, I'm thinking the shutter speed is
> fast (because the flash is firing), but the flash is not bouncing off a
> close object so the camera is picking up the light from the flash. Or
> if there is a window maybe it is picking up some outfoor light peaking in.
>
> Has anyone else seen this? Does what I suggest sound plausible?
>
> Looking for some advice on the cause.
>
> Thanks,
>
> Steve

It would help if we could see one of these photos.
You might try aiming the camera straight up on a clear night and taking
a flash photo.

Scott

Scott W wrote:
> Steven Feinstein wrote:
>
>>I have a Canon A95. Occassionally (and I'm trying to narrow down when)
>>I take a photo and I get small circular areas which are lighter than the
>>rest of the area. They remind me of what would happen when painting
>>watercolors and an area blooms (but it is a perfect circle).
>>
>>It seems to happen when the flash fires but the subject is too far away
>>or there are small areas of other sources of light. It also appears to
>>be worse at 400 ISO.
>>
>>I'm trying to figure out what is happening in order to avoid the
>>situation. If I had to make a guess, I'm thinking the shutter speed is
>>fast (because the flash is firing), but the flash is not bouncing off a
>>close object so the camera is picking up the light from the flash. Or
>>if there is a window maybe it is picking up some outfoor light peaking in.
>>
>>Has anyone else seen this? Does what I suggest sound plausible?
>>
>>Looking for some advice on the cause.
>>
>>Thanks,
>>
>>Steve
>
>
> It would help if we could see one of these photos.
> You might try aiming the camera straight up on a clear night and taking
> a flash photo.
>
> Scott
>
I uploaded three images as examples. Dust does seem to make sense, it's
just that we took pictures at the same locations in a previous year
using a point and shoot film camera and did not have this problem. Does
it sound more like chance or is digital more sensitive to the dust?

Light areas are:
lapel of man
knee of boy
above white banner
http://members.cox.net/sfein/images/img_1300.jpg

Light areas are:
at bottom
on right near door
http://members.cox.net/sfein/images/img_1258.jpg

Light areas are all over the place:
http://members.cox.net/sfein/images/img_1254.jpg

I appreciate all the help from everyone.

Steven Feinstein wrote:
[]
> I uploaded three images as examples. Dust does seem to make sense,
> it's just that we took pictures at the same locations in a previous
> year using a point and shoot film camera and did not have this
> problem. Does it sound more like chance or is digital more sensitive
> to the dust?

Yes. I already explained that to you - please re-read my post.

David

On Fri, 01 Jul 2005 13:31:28 -0400, Steven Feinstein
<> wrote:

>Frank ess wrote:
>> Steven Feinstein wrote:
>>
>>> I have a Canon A95. Occassionally (and I'm trying to narrow down
>>> when) I take a photo and I get small circular areas which are lighter
>>> than
>>> the rest of the area. They remind me of what would happen when
>>> painting watercolors and an area blooms (but it is a perfect circle).
>>>
>>> It seems to happen when the flash fires but the subject is too far
>>> away or there are small areas of other sources of light. It also
>>> appears to be worse at 400 ISO.
>>>
>>> I'm trying to figure out what is happening in order to avoid the
>>> situation. If I had to make a guess, I'm thinking the shutter speed
>>> is fast (because the flash is firing), but the flash is not bouncing
>>> off a close object so the camera is picking up the light from the
>>> flash. Or if there is a window maybe it is picking up some outfoor light
>>> peaking in.
>>> Has anyone else seen this? Does what I suggest sound plausible?
>>>
>>> Looking for some advice on the cause.
>>>
>> It's a mote in the middle distance.
>>
>Are you saying that the flash is reflecting off of dust? This may be
>possible since the last batch were pictures of a person riding a horse
>in an indoor arena (on dirt), but the light areas seem pretty big for
>dust. As an example, one of the areas I'm looking at is about 1/6th the
>height of the picture. Would a reflection off of dust look that large?
>
>Also, if it is a mote, am I limited to not using the flash in dusty areas?
>
>Thanks for your response.

One-sixth of the picture is an awfully large dust mote!
It would be great if you could post a link to a copy of a pic that
shows this, then we would have a much better idea of what you mean.

--
Bill Funk
replace "g" with "a"

On Fri, 01 Jul 2005 15:22:23 -0400, Steven Feinstein
<> wrote:

>I uploaded three images as examples. Dust does seem to make sense, it's
>just that we took pictures at the same locations in a previous year
>using a point and shoot film camera and did not have this problem. Does
>it sound more like chance or is digital more sensitive to the dust?
>
>http://members.cox.net/sfein/images/img_1300.jpg
>http://members.cox.net/sfein/images/img_1258.jpg
>http://members.cox.net/sfein/images/img_1254.jpg

Wow, I've never seen that before.

You can rule out dust on the surface of the lens / front filter by
taking a couple of photos in quick succession with AF switched off (to
prevent any possible front-element rotation) but framed slightly
differently. However, I'm not sure how this would get illuminated by
the flash.

So, the only other plausible idea is as others have suggested - dust
floating around in the air, quite close to the front element being
illuminated by the flash - not much you can do about that...

--
Owamanga!
http://www.pbase.com/owamanga