Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
05-01-2011, 06:39 PM   #1
Inactive Account

Join Date: Sep 2009
Location: Alabama
Photos: Gallery
Posts: 12
Spot in photos using 300MM zooms

The attached photo of a hawk was taken with a s Sigma 75-300mm. You can see a spot near the top quarter of the frame, as well as two small ones in the lower portion. I had similar spots when using a Pentax 100-300mm and thought it was the Pentax lens, but now I see it with the Sigma as well WHEN set at 300mm or somewhere in that range. Photo was taken with a K-10.

Can someone tell me the cause of this>

Attached Images
05-01-2011, 06:44 PM   #2
Veteran Member
wwwmorrell's Avatar

Join Date: Jan 2007
Location: Mount Buller, Australia
Posts: 398
Dust on your sensor.
05-01-2011, 07:01 PM   #3
Site Supporter
SpecialK's Avatar

Join Date: Dec 2006
Location: So California
Photos: Gallery
Posts: 14,901
At least 5 spots. A Giotto rocket blower is essential.
05-01-2011, 07:16 PM   #4
Inactive Account

Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
It's dirt on the sensor..

Your lens would have to be VERY cruddy for it to show up in a photo.

05-01-2011, 11:25 PM   #5
Site Supporter
Bramela's Avatar

Join Date: Jan 2007
Location: Newcastle Australia
Photos: Gallery | Albums
Posts: 5,281
Blower is what you need. but DO NOT touch the sensor with a cloth etc. Scratches, which will be very tiny on the sensor would show up as huge on a photo. Can ruin your camera.
05-02-2011, 04:42 AM   #6
Inactive Account

Join Date: Mar 2007
Location: Long Island, N.Y.
Photos: Gallery
Posts: 1,124
I have found with my K10D that simply blowing isn't always enough to remove the dust. The K10D seems to be worse than other models in this regard.
Step one is always as others have said, simply blowing out the box, then opening the mirror and blowing out the sensor area (with the camera pointed down.
Then take a picture of a clear evenly lit empty sky using a small aperture and inspect the resulting picture for spots.
Step two (I need to do this about 3/4 of the time when I clean) is to dab clean the sensor using something like the "Pentax Lollipop" (mine is sold by Dot Line Corp and appears identical).
Then take a test picture again.
If needed (I haven't yet) the third step is a wet cleaning or professional cleaning.

In any and all cases, be very careful not to scratch the sensor's filter.
05-02-2011, 01:27 PM   #7
Inactive Account

Join Date: Sep 2009
Location: Alabama
Photos: Gallery
Posts: 12
Original Poster
It isn't the lens...
05-02-2011, 03:28 PM   #8
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 6,283
QuoteOriginally posted by mobygrape Quote
It isn't the lens...

05-02-2011, 05:50 PM   #9
Inactive Account

Join Date: Sep 2009
Location: Alabama
Photos: Gallery
Posts: 12
Original Poster

  • 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!
300mm, pentax, pentax help, photo, sigma, spot
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: DA 40mm and fine AF zooms: DA 55-300mm, Tamron 70-200mm/2.8, 28-75mm/2.8, Sig farfisa Sold Items 20 07-25-2010 02:36 PM
For Sale - Sold: Exceptional zooms - Tamron 17-35mm di and Sigma 70-300mm apo di tundraguide Sold Items 5 07-17-2010 05:04 PM
Soft spot in photos? Humidity? Settings bugsy603 Photographic Technique 9 06-14-2010 06:52 PM
Zooms ending in 250-300mm range Laurentiu Cristofor Pentax SLR Lens Discussion 22 06-13-2010 02:32 PM
brown spot on photos annod Pentax SLR Lens Discussion 6 10-05-2009 10:22 PM

All times are GMT -7. The time now is 04:05 PM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]