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dark spots showing in my 7i shots

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guslee

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Grateful for any advice you can offer.

Please see the four photos taken with a 7i in http://www.pbase.com/insane/problem

Black spots start appearing in some of my shots in the past month or two. These spots vary in size but would stay at the same general location in the photos. As evident from the two versions of PICT 9422 below, the spot could have hidden itself in all my photos, but be masked out by other information in most cases and would only show up under certain exposure combination.

I have a UV filter (Kenko L37 SuperPro). I also have been particularly careful in cleaning the lens and the filter lately. That didn't help.

I don't think these trouble spots are casued by lens flare since various angle to the sun did not change the relative positon of these spots in the photos.

I took a number of test shots tonight with different focal length at plain black, white, red, dark blue and light blue papers under a florescent lamp. Such trouble spots did not show up in these test shots.

What could be causing these trouble spots in my photos? Could internal dirt built up within the lens be blamed? Or could it be a problem of reduced sensitivity of a group of CCD cells damaged before by long exposure to a strong light source (I really can't recall such an incident unless one of the sunrise/sunset scenes did it)?

By the way, my 7i just grows on me. I love it more by the day.
 
guslee said:
Grateful for any advice you can offer.

Please see the four photos taken with a 7i in
http://www.pbase.com/insane/problem

Black spots start appearing in some of my shots in the past month
or two. These spots vary in size but would stay at the same general
location in the photos. As evident from the two versions of PICT
9422 below, the spot could have hidden itself in all my photos, but
be masked out by other information in most cases and would only
show up under certain exposure combination.

I have a UV filter (Kenko L37 SuperPro). I also have been
particularly careful in cleaning the lens and the filter lately.
That didn't help.

I don't think these trouble spots are casued by lens flare since
various angle to the sun did not change the relative positon of
these spots in the photos.

I took a number of test shots tonight with different focal length
at plain black, white, red, dark blue and light blue papers under a
florescent lamp. Such trouble spots did not show up in these test
shots.

What could be causing these trouble spots in my photos? Could
internal dirt built up within the lens be blamed? Or could it be a
problem of reduced sensitivity of a group of CCD cells damaged
before by long exposure to a strong light source (I really can't
recall such an incident unless one of the sunrise/sunset scenes did
it)?

By the way, my 7i just grows on me. I love it more by the day.
Click to expand...
My english ist not the best, but I had the same problem. Spots in the SKy.
I had change the D7i by my dealer.

I habe found all Minolta Kamera have a problem, the Minolta quality management ist not good for the price.

My faults by Minolta, see my picture in the Link.
Dead pixel in the EVF; Spot in the sky; right top corner shade.

Here you are my link: http://home.t-online.de/home/340036650854/___M/Dokument1.htm

Have a nice day Gerd
 
Hi Guslee, I am following this board about a year and I have never seen anything published about such kind of dark spots. Thinking it over it seems me some particle somehwere in the light path, maybe even glass. Can you change its place by "shivering" the camera ? I suppose that you saw nothing, looking from outside through the series of lens elements at the frontside? However, it is not normal and my advise would be to send your camera to a Minolta service center.
Good luck.
Hans
guslee said:
Grateful for any advice you can offer.

Please see the four photos taken with a 7i in
http://www.pbase.com/insane/problem

Black spots start appearing in some of my shots in the past month
or two. These spots vary in size but would stay at the same general
location in the photos. As evident from the two versions of PICT
9422 below, the spot could have hidden itself in all my photos, but
be masked out by other information in most cases and would only
show up under certain exposure combination.

I have a UV filter (Kenko L37 SuperPro). I also have been
particularly careful in cleaning the lens and the filter lately.
That didn't help.

I don't think these trouble spots are casued by lens flare since
various angle to the sun did not change the relative positon of
these spots in the photos.

I took a number of test shots tonight with different focal length
at plain black, white, red, dark blue and light blue papers under a
florescent lamp. Such trouble spots did not show up in these test
shots.

What could be causing these trouble spots in my photos? Could
internal dirt built up within the lens be blamed? Or could it be a
problem of reduced sensitivity of a group of CCD cells damaged
before by long exposure to a strong light source (I really can't
recall such an incident unless one of the sunrise/sunset scenes did
it)?

By the way, my 7i just grows on me. I love it more by the day.
Click to expand...
 
Don't think it is dirt blocking light since the size of the spot varies. Also, however hard I look, the lens look clean to me unless the dirt is deep inside the len mechanism.

Exchanging it now may be a problem for me since (i) I had the camera for over four months, put a lot of mileage on it, and had a few dents and scretches here and there, and (ii) it is a grey market product from Japan. If I can't find any cure that I can do myself, I may send it away to Japan for repair and hope it is covered under warranty and not be charged becasue of misuses by owner.

That said, I am still curious to learn of the the casue for such a spot. If it is indeed caused by damaged CCD from the rising/setting sun I shot at before, then I have to be extra careful in future even with a new 7i. That will unfortunately take a lot of fun away.
 
Gerd,

Yes. The dark spot looks familiar, except yours are quite a big bigger.

The dark corner could nr expalined away by vignetting, possibly by a filter in front. I see the same thing with my Kenko UV filter.

Other that the dark spot, I myself am quite happy with 7i. So many features to progress with, sharp lens, good zoom range and the essential wide angle (to me anyway). I am falling in love wiht the manual zoom as well..... Don't think I will be switching to other make for quite some time. It gives me everything I want for the moment, and more.

Have a good day.

Gus
 
If it is something on the lens, or a defect in the lens, it might indeed show up more in some light, and at some focal lengths, than others. It's got to be something in the light path, not a CCD problem.
guslee said:
Grateful for any advice you can offer.

Please see the four photos taken with a 7i in
http://www.pbase.com/insane/problem

Black spots start appearing in some of my shots in the past month
or two. These spots vary in size but would stay at the same general
location in the photos. As evident from the two versions of PICT
9422 below, the spot could have hidden itself in all my photos, but
be masked out by other information in most cases and would only
show up under certain exposure combination.

I have a UV filter (Kenko L37 SuperPro). I also have been
particularly careful in cleaning the lens and the filter lately.
That didn't help.

I don't think these trouble spots are casued by lens flare since
various angle to the sun did not change the relative positon of
these spots in the photos.

I took a number of test shots tonight with different focal length
at plain black, white, red, dark blue and light blue papers under a
florescent lamp. Such trouble spots did not show up in these test
shots.

What could be causing these trouble spots in my photos? Could
internal dirt built up within the lens be blamed? Or could it be a
problem of reduced sensitivity of a group of CCD cells damaged
before by long exposure to a strong light source (I really can't
recall such an incident unless one of the sunrise/sunset scenes did
it)?

By the way, my 7i just grows on me. I love it more by the day.
Click to expand...
 
I had a spot like this, and it went away when I cleaned a spot off my UV filter.

I think it happens especially on wide angle shots, where the depth of field is very large, especially at 7mm true focal length. On my old SLR spots like this did not show up on the film.

So I would look again, and maybe try without the filter.
guslee said:
Grateful for any advice you can offer.

Please see the four photos taken with a 7i in
http://www.pbase.com/insane/problem

Black spots start appearing in some of my shots in the past month
or two. These spots vary in size but would stay at the same general
location in the photos. As evident from the two versions of PICT
9422 below, the spot could have hidden itself in all my photos, but
be masked out by other information in most cases and would only
show up under certain exposure combination.

I have a UV filter (Kenko L37 SuperPro). I also have been
particularly careful in cleaning the lens and the filter lately.
That didn't help.

I don't think these trouble spots are casued by lens flare since
various angle to the sun did not change the relative positon of
these spots in the photos.

I took a number of test shots tonight with different focal length
at plain black, white, red, dark blue and light blue papers under a
florescent lamp. Such trouble spots did not show up in these test
shots.

What could be causing these trouble spots in my photos? Could
internal dirt built up within the lens be blamed? Or could it be a
problem of reduced sensitivity of a group of CCD cells damaged
before by long exposure to a strong light source (I really can't
recall such an incident unless one of the sunrise/sunset scenes did
it)?

By the way, my 7i just grows on me. I love it more by the day.
Click to expand...
 
guslee said:
Grateful for any advice you can offer.

Please see the four photos taken with a 7i in
http://www.pbase.com/insane/problem

Black spots start appearing in some of my shots in the past month
or two. These spots vary in size but would stay at the same general
location in the photos. As evident from the two versions of PICT
9422 below, the spot could have hidden itself in all my photos, but
be masked out by other information in most cases and would only
show up under certain exposure combination.

I have a UV filter (Kenko L37 SuperPro). I also have been
particularly careful in cleaning the lens and the filter lately.
That didn't help.

I don't think these trouble spots are casued by lens flare since
various angle to the sun did not change the relative positon of
these spots in the photos.
Click to expand...
I had a similar problem show up in an Olympus, only white spots rather than dark. It is my understanding that the CCD can develop a "hot" spot (white spot) or "cold" spot (dark spot) and is considered to be within normal operating parameters if it is less that 5 x 5 pixels in size. Anything greater than 5 x 5 pixels is outside of normal parameters and should be sent to the manufacturer for repairs. If your camera does develop this it will show up in every shot, but in some lighting will be harder to differentiate than in others. (a white spot is almost impossible to find when sooting a cloud, but shows up immediately whn shooting a black background and vice versa).
guslee said:
By the way, my 7i just grows on me. I love it more by the day.
Click to expand...
Me too

Hope this helps

Keith
 
Hans said:
it seems me some particle somehwere in the light path, maybe
even glass. Can you change its place by "shivering" the camera ?
Click to expand...
Dear Hans,

I gave your suggestion more thoughts on my way to work, and realise the logics given in my earlier reply by saying the size of the spot varies would rule out the possiblity of dirt lodged inside the lens is flaw. Come to think of it, depending on the focal length/zoom range used, and where the dirt is positioned within the lens, such a dirt could indeed project itself on the photos with differnt sizes.

I also can confirm that by shivering the camera, the relative position of the dark spot did not change. As a matter of fact, all the dark spots I saw in the dozens of shots I had so far are located in the exact same position of these photos.

One thing puzzling is the spot only shows up in certain type of blue sky. Physical blockage by dirt blocks all colours of light. Another puzzle is the test shots I had last night (by shooting at color papers with different focal length) did not trigger such troubled dark spot.

As indicated in my last reply, the major concern I have is damaged CCD (clipped sensitivity of photocells to certain color of light) because of sunrise/sunset shots since this could mean my new 7i, as well as those of others, could be similiarly damaged.

Thanks for your kind response.

Have a good day.

Gus
 
guslee said:
Grateful for any advice you can offer.

Please see the four photos taken with a 7i in
http://www.pbase.com/insane/problem

Black spots start appearing in some of my shots in the past month
or two. These spots vary in size but would stay at the same general
location in the photos. As evident from the two versions of PICT
9422 below, the spot could have hidden itself in all my photos, but
be masked out by other information in most cases and would only
show up under certain exposure combination.

I have a UV filter (Kenko L37 SuperPro). I also have been
particularly careful in cleaning the lens and the filter lately.
That didn't help.

I don't think these trouble spots are casued by lens flare since
various angle to the sun did not change the relative positon of
these spots in the photos.

I took a number of test shots tonight with different focal length
at plain black, white, red, dark blue and light blue papers under a
florescent lamp. Such trouble spots did not show up in these test
shots.

What could be causing these trouble spots in my photos? Could
internal dirt built up within the lens be blamed? Or could it be a
problem of reduced sensitivity of a group of CCD cells damaged
before by long exposure to a strong light source (I really can't
recall such an incident unless one of the sunrise/sunset scenes did
it)?

By the way, my 7i just grows on me. I love it more by the day.
Click to expand...
Almost looks like heat damage from pointing the camera into the sun.
 
guslee said:
Grateful for any advice you can offer.
Click to expand...
[snip]

I'm 99% sure it's an optical problem. I know of no CCD-related mechanism that could cause a near-circular darkening to appear regularly on pictures. CCD problems tend to be either restricted to individual pixels or affect the entire sensor. One thing that could easily cause this is a minor manufacturing defect that caused some dust inside the camera, which settled on the CCD.

Try this: take a set of pictures of clear blue sky at 28 mm, varying the aperture from f/2.8 to f/8 in 1-stop steps. If the visibility of the spot varies, it's certainly an optical problem. In any case, it's warranty service time.

Petteri
--
http://www.seittipaja.fi/index/
 
guslee said:
Exchanging it now may be a problem for me since (i) I had the
camera for over four months, put a lot of mileage on it, and had a
few dents and scretches here and there, and (ii) it is a grey
market product from Japan.
Click to expand...
If I understood it well, the Minolta cameras are garanteed worldwide but the USA bought cameras have to be serviced only in the USA. I would give it a try.
Hans
 
Petteri Sulonen said:
Petteri Sulonen said:
I'm 99% sure it's an optical problem. I know of no CCD-related
Click to expand...
mechanism that could cause a near-circular darkening to appear
regularly on pictures. CCD problems tend to be either restricted to
individual pixels or affect the entire sensor. One thing that could
easily cause this is a minor manufacturing defect that caused some
dust inside the camera, which settled on the CCD.

Try this: take a set of pictures of clear blue sky at 28 mm,
varying the aperture from f/2.8 to f/8 in 1-stop steps. If the
visibility of the spot varies, it's certainly an optical problem.
In any case, it's warranty service time.

Petteri
--
http://www.seittipaja.fi/index/
Click to expand...
Many thanks. Make sense regarding CCD problem (good to know I can still point my 7i to a setting sun with peace of mind)

Will try your test procedure once there is blue sky out there. (The weather in Hong Kong the last couple of days hasn't been good, and will continue to be so for a few more days). I will report my finding here once gone thru your suggested test.

Gus
 
Well. Finally the weather cooperated and I had a chance to test out what Petteri suggested. I repeated the test three times under different blue skies.....and couldn't find the dark spot any more.

A few days before the tests, I reexamined the 7i, its UV filter under a strong light. All looked OK except I discovered a tiny tiny piece of silvery stuff ((kind of refective, looks like a very small piece of metallic tape, no more than 0.5mm in diameter) glued to the underside of my UV filter. I practically had to scrap it off with my finger nail. Hope this was THE cause of the dark spots that had been haunting me for over a month.

If this silvery dirt is indeed the casue of my past problem, then yes, it was an optical problem that I was dumb enough to have missed despite frequent checking/cleaning. And the camera was not to be blamed at all.

Thanks for all the help/suggestions offered. Much appreciated.

Gus
Petteri Sulonen said:
guslee said:
Grateful for any advice you can offer.
Click to expand...
[snip]

I'm 99% sure it's an optical problem. I know of no CCD-related
mechanism that could cause a near-circular darkening to appear
regularly on pictures. CCD problems tend to be either restricted to
individual pixels or affect the entire sensor. One thing that could
easily cause this is a minor manufacturing defect that caused some
dust inside the camera, which settled on the CCD.

Try this: take a set of pictures of clear blue sky at 28 mm,
varying the aperture from f/2.8 to f/8 in 1-stop steps. If the
visibility of the spot varies, it's certainly an optical problem.
In any case, it's warranty service time.

Petteri
--
http://www.seittipaja.fi/index/
Click to expand...
 
guslee said:
Well. Finally the weather cooperated and I had a chance to test out
what Petteri suggested. I repeated the test three times under
different blue skies.....and couldn't find the dark spot any more.

A few days before the tests, I reexamined the 7i, its UV filter
under a strong light. All looked OK except I discovered a tiny
tiny piece of silvery stuff ((kind of refective, looks like a very
small piece of metallic tape, no more than 0.5mm in diameter) glued
to the underside of my UV filter. I practically had to scrap it
off with my finger nail. Hope this was THE cause of the dark spots
that had been haunting me for over a month.

If this silvery dirt is indeed the casue of my past problem, then
yes, it was an optical problem that I was dumb enough to have
missed despite frequent checking/cleaning. And the camera was not
to be blamed at all.

Thanks for all the help/suggestions offered. Much appreciated.
Click to expand...
And thank YOU for sharing your experiences. Such follow ups make this forum so valuable. Doesn' t matter at all, who or what to blame. Congratulations.
Hans.
 
Hans said:
guslee said:
Well. Finally the weather cooperated and I had a chance to test out
what Petteri suggested. I repeated the test three times under
different blue skies.....and couldn't find the dark spot any more.

A few days before the tests, I reexamined the 7i, its UV filter
under a strong light. All looked OK except I discovered a tiny
tiny piece of silvery stuff ((kind of refective, looks like a very
small piece of metallic tape, no more than 0.5mm in diameter) glued
to the underside of my UV filter. I practically had to scrap it
off with my finger nail. Hope this was THE cause of the dark spots
that had been haunting me for over a month.

If this silvery dirt is indeed the casue of my past problem, then
yes, it was an optical problem that I was dumb enough to have
missed despite frequent checking/cleaning. And the camera was not
to be blamed at all.

Thanks for all the help/suggestions offered. Much appreciated.
Click to expand...
And thank YOU for sharing your experiences. Such follow ups make
this forum so valuable. Doesn' t matter at all, who or what to
blame. Congratulations.
Hans.
Click to expand...
I agree with Hans. Thank you guslee. This may help all of us sometime down the road.
 
When I just saw the first few posts it horrified me really, since I´m about to purchase the 7i.

I sure hope that was the problem (the silvery residue on your filter), and not the camera itself.

Romka
 
In the unlikely event the dark spots reappear, I shall report again.

Thanks to you all.

P.S after half a year later, and close to ten thousands clicks (as recorded on the register) on my 7i, I find I am actually enjoying it much much more now than the first day I had it. I am still finding and learning new and useful features on the machine. Just love it!

Earlier on, I dreamed of a D-SLR. Now, I am more than content with 7i, and can postpone my quest for a D-SLR for a long time. As one who loves to hike and go out to the countryside, the size and weight of the 7i may even suit me better than a D-SLR, considering what I myself can do with my camera. I don't think I will be bounded by the limits of the 7i for a long long time given my limited skills and experience. Call that self-realisation.

Gus
 
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