Mobius Telephoto Dashcam

jokiin said:
I believe the problem is to do with adhesive outgassing, had never really given a lot of thought about where it was originating from but given where it occurs and the fact that it can be cleaned off I guess it is quite possible it's the adhesive used on the IR filter that was the culprit, if it was from something used on the internal lens elements then the fog would end up trapped inside, only other possibility to cause a problem in that space would be from the CMOS sensor but don't know if there's anything used in the manufacturer of a sensor which could cause this, not even sure what hardware they used on these
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The IR filter adhesive outgassing fumes sounds like a good possibility. Or perhaps the glue they used to set the lens? Either way this is a good example of the kind of thing I've been talking about here and in this case at least it is still cleanable which with some contaminants might not be.
 
Dashmellow said:
The IR filter adhesive outgassing fumes sounds like a good possibility. Or perhaps the glue they used to set the lens? Either way this is a good example of the kind of thing I've been talking about here and in this case at least it is still cleanable which with some contaminants might not be.
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I originally thought it may have been the glue used to hold the lens in place and never really thought about the possibility that it was the glue on the IR filter which was causing it, there's a lot more glue used on the lens threads but logically that is perhaps less likely to get to where it does, it's a tiny amount that gets used to hold the IR filter in place but that may also account for why it generally took one to two years for the problem to even show up
 
jokiin said:
I originally thought it may have been the glue used to hold the lens in place and never really thought about the possibility that it was the glue on the IR filter which was causing it, there's a lot more glue used on the lens threads but logically that is perhaps less likely to get to where it does, it's a tiny amount that gets used to hold the IR filter in place but that may also account for why it generally took one to two years for the problem to even show up
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Reviewing the video again I see there's quite a lot of glue on those lens threads, so maybe that's it. There's no way to ever really know. Maybe there is even some sort of foreign contaminant or solvent that got into the pcb during manufacture that is slowly outgassing onto the filter when the camera gets hot.
 
Dashmellow said:
I agree completely about not using isopropyl alcohol on optics. I highly recommend a product called ROR Mist (Residual Oil Remover). I've been using it exclusively for almost 25 years since it was first introduced and I will use nothing else on fine optical surfaces. It's the best optical cleaning fluid you can buy.

http://www.ror.net/

View attachment 36088
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That stuff is popular with photographers, but it's mostly distilled water with isopropyl and ammonia and soap... It probably leaves soap on the lens http://www.ror.net/wp-content/uploads/2009/09/Material-Safety-Data-Sheet-JUNE-20121.pdf
 
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Radius8 said:
What about this mico Lenspen:
https://www.lenspen.com/our-products/lens-and-filter-cleaning/micropro

I have the regular size and it does a good job cleaning lenses. I also have the one for cleaning screens and that also works. It these use some type of carbon to "catch" oil deposits.

Edmunds Optics has a wet cleaner, pretty reasonably priced:
https://www.edmundoptics.com/lab-pr...-pouches/8-oz.-spray-top-bottle-lens-cleaner/

Also this entertaining video is worth your 2.5 minutes :D:
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I'm a huge opponent of those "lens pen" devices. The one thing carbon can do is cause oils to clump. It doesn't actually clean, doesn't lubricate so you risk scratches, and it leaves conductive powder in your lens.
 
Talking about residual powder, the white tipped ones from Lenspen are the worst. Scratching is a concern if you aren't using a dust blower prior to using the pen.

I have the regular 3-in-1 black tipped set, the MicroPro piece works well for dashcam lenses and CPLs.

@Radius8

Look for the black tipped one, as per my experience the ElitePro series (white tip) 3-in-1 kit and the MicroPro (individual packaging) both leave residual powder.
 
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jackalopephoto said:
I'm a huge opponent of those "lens pen" devices. The one thing carbon can do is cause oils to clump. It doesn't actually clean, doesn't lubricate so you risk scratches, and it leaves conductive powder in your lens.
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I'm not a fan of those things either.

Also not a fan of "micro-fiber cloth" which tends to hold increasing quantities dust particles that get ground into lens surfaces. That stuff may be OK for eyeglasses but it shouldn't come anywhere near photographic lenses.

The traditional method of blowing off dust particles with forced air and gentle wiping with a suitable cleaning fluid and a piece of quality, virgin lens paper is the way to go.
 
Just noticed, 8mm's frame is larger than the other two, will correct and upload again in a bit.
 
Harsh said:
Just noticed, 8mm's frame is larger than the other two, will correct and upload again in a bit.
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They seem a little out of focus. Just this morning I noticed my 6mm ƒ/1.2 Mobius seems a bit out of focus too. Must be something going around. :)
 
Dashmellow said:
They seem a little out of focus. Just this morning I noticed my 6mm ƒ/1.2 Mobius seems a bit out of focus too. Must be something going around. :)
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Focus looks to be where it was set. 8 and 12 are a little jumpy due to the overall weight. Need to add a fresh layer of EVA foam to the mounting plate.
 
Harsh said:
Focus looks to be where it was set. 8 and 12 are a little jumpy due to the overall weight. Need to add a fresh layer of EVA foam to the mounting plate.
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I didn't watch the whole thing due to my crappy bandwidth. For some reason YouTube is one of the most problematic video sources for me. I'll check your newly uploaded video again later. Personally, I'm still finding the hyperfocal sweet spot on the 6mm is a little tricky, especially trying to focus through a closed window in wintertime.
 
Dashmellow said:
Personally, I'm still finding the hyperfocal sweet spot on the 6mm is a little tricky, especially trying to focus through a closed window in wintertime.
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I had a similar experience with the 4mm f/1.2, even with the sun out and the camera looking at a red-brick wall.
 
Harsh said:
I had a similar experience with the 4mm f/1.2, even with the sun out and the camera looking at a red-brick wall.
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The ƒ/1.2 lenses don't give you too much room for error with the shallow depth of field they provide. Sometimes, I find that what looks good when I'm focusing doesn't look quite so good when I go to shoot actual video and so then I'll have to go back and make an adjustment.
 
Dashmellow said:
Sometimes, I find that what looks good when I'm focusing doesn't look quite so good when I go to shoot actual video and so then I'll have to go back and make an adjustment.
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Though I ran it for just 3 or 4 days, this is exactly what happened, had to refocus it the next day.
 
Harsh said:
Though I ran it for just 3 or 4 days, this is exactly what happened, had to refocus it the next day.
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I guess it's reassuring to hear of the same experience. As much as I'm enamored of these fast lenses, all in all I got sharper results from that Varifocal IR of mine. I'm curious to see how it compares after I do the cut filter mod.
 
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