Initial Review of IR-Cut filter by Sean Reid

[Vivek Iyer]

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Albert, Here are some free (does not mean any less) answers:

 

1. For wide angles, can't do much. You can avoid using them.

 

2. The "MRC" filters are coated on both sides. Both sides are also prone to scratches. If anyone tells you otherwise, they are lying.

 

If you want real scratch resistant filter, get a Baader Planetarium filter. The best.

 

But, only available in 48mm and 25mm sizes.

[sean_reid]

I received a technical report on the 486 UV/IR filter from Schneider where they stated that the filter is not suited for any lens with an angle of view greater than 60 degrees.

This translates into any lens with a focal length of less than about 38mm.. Why, because the angle of incidence in wide angle lenses is greater at the periphery andhence this causes a color shift. Blues become darker at the periphery...

My questions to all are the following:

1. If correct, waht does one do for any lens shorter than 38mm?

2. Only one side o fhte filter is coated with MRC and the other seems to be uncoated... How do we clean it if necessary without damaging the uncoated side?

 

Albert,

 

I imagine you must not have seen the discussions but this is the phenomena of red vignetting/cyan drift. Version 1.10 of the M8 firmware will automatically compensate for this when coded lenses and 486 filters are used on the camera. The 486 filters are coated on both sides. The outside is an anti-reflective coating and the inside holds the many coatings (perhaps 30 or so, I can't recall) that are needed for the IR filtration. One can clean either side but it is wise to not be too aggressive when cleaning the inside. It goes without saying, I suppose, that this issue has been extensively tested, discussed, etc. on my site and on this forum for the past several months.

 

Cheers,

 

Sean

[sean_reid]

Albert, Here are some free (does not mean any less) answers:

 

1. For wide angles, can't do much.

 

I'm afraid that's not true, there are several ways to deal with cyan drift.

 

Cheers,

 

Sean

[hankg]

Has anyone seen a 60mm 486 filter listed anywhere?

[sandymc]

I'm also a subscriber to Sean's site, and agree his review is is very useful.

 

But I'm still confused about how this will work in practice. If I understand correctly, the M8 will correct in firmware for both DNG and JPEG files. But how does the camera know whether an IR filter is attached at all? A menu setting, or does it just assume?

 

Sandy McGuffog

[holgerf]

I'm also a subscriber to Sean's site, and agree his review is is very useful.

 

But I'm still confused about how this will work in practice. If I understand correctly, the M8 will correct in firmware for both DNG and JPEG files. But how does the camera know whether an IR filter is attached at all? A menu setting, or does it just assume?

 

Sandy McGuffog

 

Yes, menu setting included in firmware 1.10.

 

Best

Holger

[jaapv]

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Thanks very much for the comments all. Leica needs to get *a lot* of 486 filters out and I can see how they might be hard to find now. Tony Rose might have some and several have mentioned Foto Huppert in Germany.

 

BTW, I'm trying to get a draft of the 50s article up tonight.

 

Cheers,

 

Sean

Has anyone seen a 60mm 486 filter listed anywhere?

 

 

 

 

Fotohuppert sent me a mail yesterday that he has ALL IR cut filters in stock.

[Guest guy_mancuso]

I just recieved a 60mm yesterday from them ordered about a week ago for my 75 lux . i had a 62mm converted but could not put a cap on so I ordered one and they seem they have stock

[carstenw]

Fotohuppert sent me a mail yesterday that he has ALL IR cut filters in stock.

I can confirm that Huppert probably has the 39mm and 46mm filters, since I just received both of these from them.