Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-29-2011, 10:26 AM   #1
Junior Member




Join Date: Nov 2010
Location: Toronto, ON
Posts: 49
Do I need to get my lens cleaned?

So I've had this M-50mm F1.4 for about 3-4 months now and I notice that my bokeh shots have these things in all of them. Does anyone know what could be causing them? Should I go and get this lens checked out? Personally it doesn't bother me THAT much in other shots. mostly curious...

Attached Images
 
10-29-2011, 10:56 AM   #2
Site Supporter
Deimos's Avatar

Join Date: Oct 2010
Location: Kingdom of Wonder
Posts: 1,711
I have no idea but could it be fungus? Have you taken a good look through your lens from the front and back elements on various angles in good light? If you see any strands that look like the stuff in your bokeh on the glass elements (inside or out) its prob fungus. Which I think can be cleaned but could be pricey.

Is the lens hazy at all in its general performance?

I am no expert though, maybe this is some other phenomenon
10-29-2011, 12:30 PM   #3
Pentaxian
Wheatfield's Avatar

Join Date: Apr 2008
Location: The wheatfields of Canada
Posts: 10,195
Can you post a picture of the glass? That should be visible on one of the lens elements if it is a lens artifact.
10-30-2011, 02:09 PM   #4
Junior Member




Join Date: Nov 2010
Location: Toronto, ON
Posts: 49
Original Poster
As requested, here are some images.

Attached Images
       
10-31-2011, 04:11 AM   #5
Veteran Member




Join Date: Dec 2009
Location: Ontario
Posts: 550
I see no fungus in the lens bur lots of specks but that shouldnt be causing that problem i think
10-31-2011, 04:27 AM   #6
Pentaxian
Wheatfield's Avatar

Join Date: Apr 2008
Location: The wheatfields of Canada
Posts: 10,195
Wondering if it isn't perhaps something on the sensor and we are seeing a reflection off the rear element.
10-31-2011, 09:05 AM   #7
Inactive Account




Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
Shine a flashlight through the lens while looking at it from the other end. That will reveal everything that is inside the lens. If you see something with a pattern that matches the one in your shots, then yes, the lens could stand a cleaning.

10-31-2011, 02:28 PM   #8
Junior Member




Join Date: Nov 2010
Location: Toronto, ON
Posts: 49
Original Poster
Okay I've just checked and I think it is the little specks I have in there . Looks like I will need to get it cleaned. What would be a ballpark price for something like this?

10-31-2011, 04:01 PM   #9
Veteran Member
borno's Avatar

Join Date: Nov 2006
Location: md-usa
Photos: Gallery | Albums
Posts: 2,580
I think the pattern you are seeing is possibly just imperfections in the glass. There was an interesting old thread on bokeh and specular highlights that had some good examples of patterns in the highlights though they were usually concentric circular patterns usually on lenses with an aspherical element. I doubt cleaning would have any effect, I may be wrong though.
10-31-2011, 09:48 PM   #10
Inactive Account




Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
QuoteOriginally posted by KeithM2 Quote
Okay I've just checked and I think it is the little specks I have in there . Looks like I will need to get it cleaned. What would be a ballpark price for something like this?
You would have to see THAT pattern and it would have to be covering a LOT of lens surface in order to cause that in back lit bokeh like that. If all you are seeing is little specs, you might see a dot or 3 in your bokeh but I doubt that they are causing what you show in your original post. Fungus is quite obvious when seen.

11-01-2011, 06:12 AM   #11
Veteran Member
Philoslothical's Avatar

Join Date: May 2011
Posts: 1,723
I'd suggest you clean the back element (again? assuming that was the first thing you did) and test again, see if there's any change. Looks almost like a bit of greasy something on the back element to me, but I'm just speculating. It's out of focus in your shots, so I can't see how clean it is there.
11-02-2011, 07:49 AM   #12
Junior Member




Join Date: Nov 2010
Location: Toronto, ON
Posts: 49
Original Poster
I've cleaned the elements as best I can. The dust bits are all internal for sure and I see the littlest resemblance to the bokeh I showed in the original shot given the right orientation.
Attached Images
   
11-02-2011, 09:47 AM   #13
Site Supporter
Deimos's Avatar

Join Date: Oct 2010
Location: Kingdom of Wonder
Posts: 1,711
I could be wrong but that second pic looks like it could be fungus, especially around the back element edge and bottom right area.

It would seem like a LOT of dust otherwise, usually you only get a few specs of dust. The fungus would be a much more likely explanation for that bokeh than dust IMHO
Reply

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!
lens, pentax help, shots
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need to have a lens cleaned - Where to go on Long Island gollm33 Troubleshooting and Beginner Help 3 09-30-2011 03:16 PM
Cleaned my K10D... GordonZA General Talk 3 07-12-2011 10:46 PM
Do I need to get my sensor cleaned? mikemike Troubleshooting and Beginner Help 18 04-07-2011 04:57 AM
My lens is not sharp after it was cleaned professionally dycz Pentax SLR Lens Discussion 2 12-17-2009 09:24 PM
Suggestions on where to get long M42 mount lens cleaned theedudenator Pentax SLR Lens Discussion 3 05-18-2009 04:35 PM



All times are GMT -7. The time now is 02:36 AM. | See also: NikonForums.com, CanonForums.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