Do I need to get my lens cleaned?

KeithM2 · 10-29-2011, 10:26 AM

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

**Deimos** · 10-29-2011, 10:56 AM

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

Wheatfield · 10-29-2011, 12:30 PM

Can you post a picture of the glass? That should be visible on one of the lens elements if it is a lens artifact.

KeithM2 · 10-30-2011, 02:09 PM

As requested, here are some images.

Attached Images

epqwerty · 10-31-2011, 04:11 AM

I see no fungus in the lens bur lots of specks but that shouldnt be causing that problem i think

Wheatfield · 10-31-2011, 04:27 AM

Wondering if it isn't perhaps something on the sensor and we are seeing a reflection off the rear element.

JeffJS · 10-31-2011, 09:05 AM

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.

KeithM2 · 10-31-2011, 02:28 PM

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?

borno · 10-31-2011, 04:01 PM

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.

JeffJS · 10-31-2011, 09:48 PM

Originally posted by KeithM2

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.

Philoslothical · 11-01-2011, 06:12 AM

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.

KeithM2 · 11-02-2011, 07:49 AM

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.

**Deimos** · 11-02-2011, 09:47 AM

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

10-29-2011, 10:26 AM	#1
KeithM2 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

11-02-2011, 07:49 AM	#12
KeithM2 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

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10-29-2011, 10:56 AM	#2
Deimos Site Supporter Join Date: Oct 2010 Location: Kingdom of Wonder Posts: 1,777	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
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,565	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
KeithM2 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
epqwerty 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
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,565	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
JeffJS 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
KeithM2 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
borno Veteran Member 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
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Originally posted by KeithM2 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
Philoslothical Veteran Member Join Date: May 2011 Posts: 1,889	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.

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11-02-2011, 09:47 AM	#13
Deimos Site Supporter Join Date: Oct 2010 Location: Kingdom of Wonder Posts: 1,777	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