Strange Flare

sirvine · 02-24-2007

I cleaned my sensor the other day because it was covered in dust bunnies, but now I've got this scary flare coming from every point light source, no matter which lens I use. I was pretty careful, but now I wonder if I've left a film or damaged the sensor coating.

Does anyone recognize this effect?

Benjamin Marks · 02-24-2007

I would check the sensor to make sure that there is nothing smeared on it (a fingerprint?). Otherwise have a look at your lens. The eccentric circles remind me of flare from having the sun pass obliquely through an aperture. Other than that, I'm stumped. You say it's every point light source?

sirvine · 02-24-2007

Well it keeps showing up from streetlights, but I ran some tests here at home and got some clean shots of my desklamps. I never noticed it, but I guess I should give it a little more time to see if it keeps happening.

The sensor looks super-clean to the eye. It was the fact that this artifact showed up with two different lenses ('cron 50 and nokton 40) that freaked me out.

rsl · 02-24-2007

The fact that the sensor "looks clean to the eye" doesn't mean a thing. You can't see the kind of dust on a sensor that can ruin a shot. The only valid test of sensor cleanliness is to shoot a blue sky (or equivalent) with the lens manually focussed on its closest distance and the aperture as small as possible -- f/16 or more. Once you get the shot, bring it into Photoshop or Elements and use the Image->Adjustments->Auto Levels menu sequence to emphasize the dust. You'll see it. It's almost impossible to completely clean a sensor filter.

What did you use to clean your sensor?

sirvine · 02-24-2007

I should have been more clear: the level of dust on the sensor is acceptable after cleaning. I tested it the normal way (shooting a uniform color field at high ISO/wide aperture, etc.) This flare made me wonder if there was a film or damage to coating that wouldn't show up in that kind of testing.

rsl · 02-24-2007

Again, what did you use to clean the sensor? Did you use a PecPad or a Sensor Swab with Eclipse? If not you may have smeared some kind of crap on there that produces the flare.

High ISO and wide aperture isn't the way to test for sensor cleanliness unless by wide aperture you mean f/16 or higher. The ISO doesn't have anything to do with it.

sirvine · 02-24-2007

Sorry, Russel, I'm stumbling on my words tonight. I meant narrow, not wide (yes, f16 in this case).

I used a SensorKlean pen. I'll try a sensor swab when I can get ahold of one. Then I can leave it alone for a while, I hope.

rsl · 02-24-2007

Good luck. I take it you know about the Copperhill cleaning method. If not, you can read all about it at http://www.pbase.com/image/15473243. I've been using that method for years with everything from a D100 on up to a D2X and my recently acquired R-D1 which came with what looked like oil smears on the sensor. There are other methods, but this one works for sure. I don't know anything about the SensorKlean pen.

sirvine · 02-24-2007

Good tip. Wish I'd known about it yesterday! That's quite a read, too. I got to page four before I figured out what the hell he was talking about: "The main thrust of this tutorial is that sensor swabbing requires you to wrap a well designed swab with a PecPad, put a drop of methanol on it and wipe a small surface that is similar to glass." LOL.

LCT · 02-24-2007

Quote:

Originally Posted by sirvine

...Does anyone recognize this effect?...

I've got such effects by night from time to time.
If the sensor is clean, if you didn't use a filter on your lens and if you didn't take your crop in the center of the picture, it comes probably from light reflections between the sensor and the AA filter.

RML · 02-25-2007

I agree with LCT that this kind of flare is rather normal for the R-D1. You can see it in many of my photos taken with the R-D1 ( http://shardsofphotography2.blogspot.com/ ), especially with street lights.

On the subject of sensor cleaning... there are easier and cheaper ways than the Copperhill method and the like. I simply use a blower to remove big particles, and Q-tips + alcohol ketonatus (70% alcohol) to clean the sensor (or better, the glass covering the sensor). See here for my experiences ( http://shardsofphotography.blogspot....-cleaning.html ).

rsl · 02-25-2007

Quote:

Originally Posted by RML

I agree with LCT that this kind of flare is rather normal for the R-D1. You can see it in many of my photos taken with the R-D1 ( http://shardsofphotography2.blogspot.com/ ), especially with street lights.

On the subject of sensor cleaning... there are easier and cheaper ways than the Copperhill method and the like. I simply use a blower to remove big particles, and Q-tips + alcohol ketonatus (70% alcohol) to clean the sensor (or better, the glass covering the sensor). See here for my experiences ( http://shardsofphotography.blogspot....-cleaning.html ).

Absolutely. If all you have on the sensor is dust you can, and should, either blow it off with an ear syringe (or more expensive equivalent) or use something like the Arctic Butterfly. It doesn't make sense to swab the sensor unless you have oil or dust that's welded itself to the filter.

Too bad that Nicholas at Copper Hill got into the business in such a big way. His web has become a nightmare of unnecessary verbiage as Sirvine pointed out. Back when I first started looking for a good way to clean the sensor on my D100 he had about a five page web that simply explained the method he'd found for sensor cleaning and offered a swab for sale for a couple bucks. He also had links to places where you could buy Pec pads and Eclipse. Now he's moved uptown and the site is very hard to deal with.

pfogle · 02-25-2007

Simple alternative to Arctic Butterfly - buy a white-fibre square end artists paintbrush (trade name Daklon) and use a Rocket blower to charge it. You can then lift off the dust particles by electostatic attraction, don't even need to touch the sensor at all. I use a bright LED flashlight to see the dust - easy as pie

sirvine · 02-25-2007

Remy,

First of all your photos are really top-notch. Your site is a real testament to the power of the R-D1 in good hands. Secondly, I learned some things from browsing your site. I learned that there is at least one cafe in Amsterdam that sells coffee to go (a change, I think, since when I lived there in '98), and I also learned that this artifact *is* in fact normal for the R-D1. You've got one here: http://photos1.blogger.com/blogger/2...SN1341b-sm.jpg

Thanks!

mwooten · 02-25-2007

I really hadn't noticed this "special effect" until reading this thread. I went down to Atlanta to the motorcycle show yesterday, and found that all of my shots that showed the ceiling mounted spotlights had the light slur in them. The color ones had a cyan shift to them. I was using an Ultron 28 on my RD1s.

Michael

RML · 02-25-2007

Quote:

Originally Posted by sirvine

First of all your photos are really top-notch. Your site is a real testament to the power of the R-D1 in good hands. Secondly, I learned some things from browsing your site. I learned that there is at least one cafe in Amsterdam that sells coffee to go (a change, I think, since when I lived there in '98), and I also learned that this artifact *is* in fact normal for the R-D1. You've got one here: http://photos1.blogger.com/blogger/2...SN1341b-sm.jpg

Thanks, Sirvine. Glad to be of some help.

It's not just the one you picked. There many others. Some are more subtle than others, though. At first it bothered me but now I don't mind anymore. I have no idea how to get rid of it, if that's possible, and I'm loath to put in all the effort to find out.

sirvine · 02-25-2007

Well, as long as I didn't cause it by doing something stupid, I can live with it!

sevres_babylone · 02-25-2007

Interesting thread. But I thought the flare was a filter thing. I have this in my night shots, as well.

sirvine · 02-25-2007

I don't have any filter on my Nokton 40, which is what that crop above is from.