Forgot Password
Pentax Camera Forums Home
 

Closed Thread
Show Printable Version Search this Thread
12-05-2010, 03:05 AM   #46
Site Supporter
Rense's Avatar

Join Date: Dec 2008
Location: Zetten - The Netherlands
Photos: Gallery | Albums
Posts: 8,812
Same here! Stains.....
# 3839xxx


Last edited by Rense; 12-05-2010 at 03:18 AM.
12-05-2010, 04:07 AM   #47
Veteran Member




Join Date: Jan 2009
Location: Budapest
Posts: 821
QuoteOriginally posted by stevebrot Quote
Let me get this straight...these cameras are all on warranty, right?
For some of us that still means sending it in for repair and then waiting several weeks or even months. After paying premium price for the new top of the line camera, waiting several weeks or months to replace a faulty cam doesn't sound reasonable or fair.
Unfortunately I can't return it to the shop because I'm way out of the return period
12-05-2010, 04:22 AM   #48
Inactive Account




Join Date: Sep 2010
Location: Norway
Posts: 22
#3850xxx
I get those ďstainsĒ in my shots. Tested with different lenses. Not dust, but that typical pattern of a string of drops as if something has splashed on to the sensor.

The stains get more visible/sharper at higher aperture. Also, they get sharper the closer I focus.
What I donít understand is just that. Aperture and focus affects the image coming through the lens. (Maybe Iím dumb but...) How/why does it makes a difference if those stains are on the sensor itself?
(Tested with different lenses and itís not the lens.)

infinit focus


close focus
12-05-2010, 05:00 AM   #49
Veteran Member
borno's Avatar

Join Date: Nov 2006
Location: md-usa
Photos: Gallery | Albums
Posts: 2,580
I'm guessing some excess oil may get on the sensor from the mirror or shutter when they are operated when new. I remember canon had that happen on some 1d bodies. They did admit to it and clean the affected bodies. Just a guess.

12-05-2010, 05:35 AM   #50
New Member




Join Date: Aug 2010
Posts: 4
I live in shanghai and was ready to update to K5 from K10. Fortunately I was aware of the problem so i carefully checked the bodies ... 4 of them and not a single clean one ! All with the problem explained above (long strain of concentrated 'dots').
VERY disappointing !!!. Anyone knows where to buy a clean-sensor K5 in Shanghai ?
12-05-2010, 05:35 AM   #51
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
QuoteOriginally posted by Wiker Quote
What I don’t understand is just that. Aperture and focus affects the image coming through the lens. (Maybe I’m dumb but...) How/why does it makes a difference if those stains are on the sensor itself?
Read my post higher up.

Of course, the stains are not on the sensor itself.

Assuming the stains have no focussing property, I would be able to compute the exact distance of the stains above microlenses. And thereby identify the surface which carries the stains (there are ~8 transmissive surfaces on top of the sensor). I would need 100% crop images of the stains at f/16, f/22, f/32. Against a gray background at infinity focus.

Close focus increases the effective aperture stop which is why it increases the effect. Close focus is ok if I know the focus distance too.
12-05-2010, 06:19 AM   #52
Inactive Account




Join Date: Oct 2009
Location: Lille, France
Photos: Gallery
Posts: 27
QuoteOriginally posted by falconeye Quote
Read my post higher up.

Of course, the stains are not on the sensor itself.

Assuming the stains have no focussing property, I would be able to compute the exact distance of the stains above microlenses. And thereby identify the surface which carries the stains (there are ~8 transmissive surfaces on top of the sensor). I would need 100% crop images of the stains at f/16, f/22, f/32. Against a gray background at infinity focus.

Close focus increases the effective aperture stop which is why it increases the effect. Close focus is ok if I know the focus distance too.
Here a link to a full size image at F22 and at infinity focus, with flash. The background is a white painted wall in my house.

http://pscl57.free.fr/K5/F22-stains.JPG

The two persitent stains are near the center of the image at left.

Last edited by pscl57; 12-05-2010 at 06:24 AM. Reason: add quote
12-05-2010, 06:25 AM   #53
Inactive Account




Join Date: Aug 2010
Location: Singapura
Posts: 23
OMG, Actually I noticed this 2 dotted stain on my pic. Then I check my sensor under a bright light and couldnt find any dust at all. But already taken many shutters till I notice this last week. Decided to send to the distributor next week thinking it was just a small particle dust can ask them to clean. Till u guys posted this. Sighed

12-05-2010, 06:29 AM   #54
Site Supporter
Rense's Avatar

Join Date: Dec 2008
Location: Zetten - The Netherlands
Photos: Gallery | Albums
Posts: 8,812
QuoteOriginally posted by falconeye Quote
Read my post higher up.

Of course, the stains are not on the sensor itself.

Assuming the stains have no focussing property, I would be able to compute the exact distance of the stains above microlenses. And thereby identify the surface which carries the stains (there are ~8 transmissive surfaces on top of the sensor). I would need 100% crop images of the stains at f/16, f/22, f/32. Against a gray background at infinity focus.

Close focus increases the effective aperture stop which is why it increases the effect. Close focus is ok if I know the focus distance too.
You can make something interesting out of a disaster, can't you???
12-05-2010, 06:54 AM   #55
Veteran Member




Join Date: Aug 2009
Location: NY
Posts: 407
QuoteOriginally posted by falconeye Quote
Read my post higher up.

Of course, the stains are not on the sensor itself.

Assuming the stains have no focussing property, I would be able to compute the exact distance of the stains above microlenses. And thereby identify the surface which carries the stains (there are ~8 transmissive surfaces on top of the sensor). I would need 100% crop images of the stains at f/16, f/22, f/32. Against a gray background at infinity focus.

Close focus increases the effective aperture stop which is why it increases the effect. Close focus is ok if I know the focus distance too.
Here are three shots top to bottom F32,F22,F16. All at Infinity.


Have at it Falk.

Last edited by telfish; 01-30-2011 at 10:17 AM.
12-05-2010, 07:18 AM   #56
Veteran Member




Join Date: Aug 2009
Location: NY
Posts: 407
Here are a couple of shots at close focus. These look like oil to me, I think most of them are oil, some round like this or smeared across the surface, either sub surface on an interior filter or on the actual surface, When I get the cleaning kit and when Falk takes a look at the crops above we will know.


I have noticed that most of these stains are pretty much horizontal and most are in the center of the sensor. Not sure what that means but it is a trend.

Terry

Last edited by telfish; 01-30-2011 at 10:17 AM.
12-05-2010, 07:20 AM   #57
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
QuoteOriginally posted by Rense Quote
You can make something interesting out of a disaster, can't you???
Well, the one desaster I've given up on making something interesting out of is Big Bang (my brain lost too many cells now). But with this one, I see match

QuoteOriginally posted by telfish Quote
Here are three shots top to bottom F32,F22,F16. All at Infinity.
I'll give it a try when I'm back home.
12-05-2010, 07:24 AM   #58
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
QuoteOriginally posted by telfish Quote
Here are a couple of shots at close focus.
Terry, close focus distance (por lens designation) required (if not in the exif).

QuoteOriginally posted by telfish Quote
These look like oil to me [...] when Falk takes a look at the crops above we will know.
I am just testing a hypothesis. The result will be far from knowing.

My hypothesis is we see core and half shadow with a bit of diffraction. From a solid object, not oil.
12-05-2010, 07:30 AM   #59
Veteran Member




Join Date: Aug 2009
Location: NY
Posts: 407
QuoteOriginally posted by falconeye Quote
Terry, close focus distance (por lens designation) required (if not in the exif).

It was taken with the 100 DFA WR macro at f32 12 inch manual focus.

I am just testing a hypothesis. The result will be far from knowing.

My hypothesis is we see core and half shadow with a bit of diffraction. From a solid object, not oil.
The only reason it looks like oil to me is the concentric circles and that is you look closely at the close focus one you can also see more opaque marks close to the dark ones. I hope it's oil and I hope it's on a cleanable surface but hope often turns into hard certainty, and not in a nice direction.
12-05-2010, 07:55 AM   #60
Veteran Member




Join Date: Aug 2009
Location: NY
Posts: 407
"Terry, close focus distance (por lens designation) required (if not in the exif)."
"

It was taken with the 100 DFA WR macro at f32 12 inch manual focus
Closed Thread

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, dslr, filter, issue, k-5, k-5 ii, k-5 iis, k5, pentax k-5, process, sensor
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax-F 17-28mm fish eye, $249 shipped US/CA, $269 shipped world wide thomasxie Sold Items 1 08-12-2009 12:16 PM
For Sale - Sold: Tiffen UV Filter 67mm $10 shipped (Fits Tamron 28-75/f2.8 XR Di) CGJung Sold Items 1 08-20-2008 09:28 PM
For Sale - Sold: Pentax DA16-45mm + UV filter $315 OBO shipped priority GatorPentax Sold Items 3 06-24-2008 06:46 PM



All times are GMT -7. The time now is 01:50 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top