Material used in replacement of EV/IR cut filters in full spectrum conversions

[Robert49]

I'm trying to find out what type of material was commonly used for clear replacement filters in full spectrum conversions around 10 years ago (Nikon D200)  Recently I've picked up something on the "glass" above the sensor and it's being extremely difficult to remove.  There's been some pollen in the air where I am so I thought the difficult part might be sticky residue.  I've tried a half dozen cleaning swipe sticks with a non-flammable (I travel a lot) sensor cleaner including letting a large amount soak on the area and it's gotten better but still noticeable.  I'm going to try to find some real (flammable) sensor cleaner but I don't have a lot of faith in where I'm traveling next.  Really trying to get a sense of how aggressive to get with this.  If I blow it I can always send the camera off for a replacement filter blank but that's a last resort.  

 

There looks, under a cellphone camera magnifier to be a minuscule whitish dot now in the area where I first saw the dust particle.  If these filter replacements are a composite or a synthetic of some type I'll probably give up on it as it may be embedded by now.  If it's truly a glass of some sort there might be some hope.     

 

In the meantime I'm open to any software fixes folks might have.  The biggest problem I have is that I use the camera a lot for time lapse sequences so we're usually talking a 1000 frames at a time.  I use NX Studio but it will not save a blemish repair as an adjustment so has to be done one by one.  Something that might allow a TIF/Jpg file in batch mode would work in my processing sequence (Mac based).  I can also hide the blemish in something busy but depending on the light it can be really annoying.  Any suggestions?

[Andy Perrin]

LifePixel sells clear replacement windows for a large variety of cameras. Look for “full spectrum” under your camera type. 

[Andrea B.]

You might also try a swab of hydrogen peroxide (drugstore strength) which we use to soak our uncoated blue-green filters when they begin to signs of deterioration. It's difficult to know whether your glass cover has begun to corrode or not. I would think not as it is plain, clear glass. It might just be that the spot is very sticky and hard to remove. You should definitely try the flammable cleaner when you can safely do so. I use Eclipse which is a very pure methanol. 

 

There is also the Lenspen. Sometimes that will get rid of a tough spot. I think that Lenspens use graphite. So I'm sitting here wondering whether a soft graphite pencil could be used to "scrub" off a tough spot. The danger of any method of sensor cleaning is that the dust bunny or spot on the sensor contains something which might scratch the glass. I don't think a sensor cover from 10 years ago used in a conversion is likely to be coated, but can't know for sure.

 

I was surprised to hear that NX Studio won't save a clone-out as a pre-set. Try one of the free converters like Gimp or Darktable?

Anybody have any suggestions for a converter which will save a clone-out as a pre-set? 

 

You could always declare the D200 obsolete and get a newer conversion? Lots of old Lumix G cams can be bought cheap for conversion. Or Sony NEXes. Or even a D300. (That was one of my favorite conversions. It just had nice colors. And that was a purely & totally subjective comment.)

 

[colinbm]

Hydrogen Peroxide is very corrosive with some metals.
Hydrogen Peroxide sank the Kursk submarine !
Perhaps Windex first ?

[Andrea B.]

Well I wasn't thinking that the hydrogen peroxide would be poured onto the sensor. 

Just use a small sensor swab.

 

HTP is very concentrated, like 80%, isn't it? Drugstore H₂O₂ is about 3%.

 

******

 

Col, did you see my remark about using a soft graphite pencil to clean a spot off glass. Is that a totally stupid idea? Or just slightly stupid? I really am curious. The funny thing is that I looked around the house for a pencil and cannot find any. All we seem to have are various kinds of pens and markers.

 

[colinbm]

The Lens Pen is useful.
I guess a soft pencil can't hurt to try, but may leave some extra graphite on the spot if it doesn't move it ?
 

[Andrea B.]

I'll try a pencil on a drinking glass and see if anything weird happens. 

 

I like those lens pens. They're also great for binoculars.

[Robert49]

Thanks for all the input so far.  I've been doing some research into what exactly is in these nonflammable cleaners and my best guess is it's just minimal alcohol.  The highest grade of alcohol I can find is what I will try next.  If, indeed, it is sticky pollen residue alcohol seems to be highly recommended.  I hadn't thought about H. Peroxide, I'll do some research into that.  I have a good number of cleaning sticks with me but foolishly I rejected buying the little spot cleaning sticks thinking I'd never use them.  I've become practiced at getting the camera perfectly horizontal and using the corner of a C size swab to deposit a small round of liquid to let soak.  I'll do more research into peroxide.  I've used the higher, 6% peroxide from beauty suppliers before for technical cleaning of non-camera gear when corrosion or staining from oxidation is present so that can be an option as well.  I've learned to start weak and move up the steps:)

 

I'm in love with the D200 because of the CCD sensor.  I can use a 2 dollar cardboard gray card and get excellent WB within a few tries with any filter or light I use.  It really speeds up nailing exposure and eliminating blown highlights.  It's a bit noisy but I've found good settings for NX that clean up the noise quickly.  I'm starting to show some concern for the # of actuations but I think I'll just buy a replacement shutter and carry it with me.  My experience with traveling is that you can usually find the technician but it's the actual parts that will be hard to find.

 

I have a couple of different lens pens and that looks like it might be an option as well.  I'll let the group know how it goes.  Thanks to all.