UV/IR filter

[musikus]

Advertisement (gone after registration)

What would be the effect of using the UV/IR filters that Leica provided in the early days of the M8 on the same lenses on an M10 as though the filters were plain UV for protective purposes?

[jdlaing]

The ones for the M 8 were UV/IR Cut filters.

When looked at from an angle they have a reddish tint.

 

Plain UV/IR filters are different and would be fine.

[lct]

What Leica calls « UV/IR » are UV/IR-cut filters actually. As mentioned by Leica in the instruction booklets, those filters are intended exclusively for use with the M8 and function as a strong barrier in the IR range. On the M10, they would cause some cyan shift i'm afraid, unless you shoot in B&W of course.

[Guest]

What would be the effect of using the UV/IR filters that Leica provided in the early days of the M8 on the same lenses on an M10 as though the filters were plain UV for protective purposes?

 

Peter Karbe, Leica's chief lens designer, told us at a lecture, that we could use UV/IR filters on every digital Leica.

One wouldn't see any differences to normal UV filters without IR specifications.

For the sensor it would be only of academic thoughts if disturbing infrared beams would be filtered out by a filter in front of the lens or a special cover glass right in front of the sensor.

Double filtering might be useless but would be without additional distortions.

So feel free to use the former special M8 UV/IR filters on any digital M as normal protection filters.

Edited September 26, 2018 by mnutzer

[UliWer]

Fortunately I still have some UV/IR Cut Filters from the times of the M8 in the cupboard. In this case a 46mm B+W 486 F-Pro UV/IR Cut.

 

The following examples were all taken with the M10 with lens detectin on "Auto" and a plastic transparent objekt immediately in front of the lenshood. No changements of the files in LR.

 

First Super-Elmar 1:3.4/21mm Asph. without filter:

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

 

Now with UV/IR Cut:

 

 

 

 

 

 

 

[UliWer]

Second

 

Summicron 1:2/28 asph without filter:

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

 

Now with UV/IR Cut

 

 

 

 

So I'do not recommend to use UV/IR Cut filters on other M_Cameras than the M8 with wide angle lenses.

 

 

[lct]

Advertisement (gone after registration)

This was my experience on M240 and A7s mod as well. Curious that Mr Karbe was not aware of that. 

[jaapv]

Second

 

Summicron 1:2/28 asph without filter:

 

28_ohne.jpg

 

 

Now with UV/IR Cut

 

 

28_UVIR.jpg

 

 

So I'do not recommend to use UV/IR Cut filters on other M_Cameras than the M8 with wide angle lenses.

I would like to see those shots with a neutralized colour balance.

Having had significant IR problems with tropical mid-afternoon sunlight, I would not like to be without an IR cut filter on any digital M. The sensor filters are barely adequate in temperate circumstances and cannot handle more extreme IR contamination.

[UliWer]

The examples for 28mm above where taken with Auto WB in camera; LR tells me Temp 5150, Tint +9 for the example without filter and Temp 5250, Tint +14 for the example with filter.

 

Now both examples changed in LR to Temp 5250, Tint 0:

 

Without filter:

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

 

With UV/IR Cut:

 

 

 

 

 

[UliWer]

I have to add that my testing method with the transparent plastic in front of the lenshood is a real "stress test". Results in reality are never as extreme.

 

If one sees the necessity to use an UV/IR Cut-Filter it will depend on the lens: focal lengthes of 50mm or longer cause much less problems and it would be worthwile to test switching off lens detection when one uses the cut-filters.

 

With wide angles known to have issues with the "Italian Flag Syndrome" one might get into the dilemma of having either magenta cast (without lens detection), cyan cast (with UV/IR Cut) or UV/IR "pollution" (without filters) - and may decide which to prefer. Personally I find the cyan cast more disturbing than the two other possibilities.    

[Guest]

Fortunately I still have some UV/IR Cut Filters from the times of the M8 in the cupboard. In this case a 46mm B+W 486 F-Pro UV/IR Cut.

...

 

Many thanks for this interesting test series, have you also repeated it with normal UV filters without IR-cut specifications?

Because that was the question to Peter Karbe: Can UV / IR cut filters be used instead of UV filters on digital M cameras that do not require UV / IR cut filters?

[UliWer]

No, I didn't do the "test" with normal UVa-Filters. 

 

Though from all I know I can say that I usually do not see differences between the results of a photo taken with UVa and without any filter - exceptions being old lenses under conditions with strong UV-light (mountains etc.) or some cases when filters cause reflections of spotlights. 

 

Anybody who owns an UVa-Filter can try whether it causes a cyan drift if he thinks Mr. Karbe meant that UVa-Filters are as bad as UV/IR-Cut-Filters in this respect with wide angle lenses on modern digital M-models.  

[UliWer]

Only to bore you furthermore...

 

Here are two different examples. Summicron 1:2/75mm Asph at f 5.6; WB adjusted in LR to Temp 4650, Tint +39 for both examples. In both cases with lens detection on "Auto".

 

First without filter:

 

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

 

 

Now with 49mm UV/IR Cut (Leica 13412):

 

 

 

 

 

I tried hard to see any differences, but I could not find anything. Same for lens detection "off" and also with UVa filter (I don't show these example, because there really is no difference).

 

To sum it up: UV/IR Cut filters can be used without any problems with lenses of 50mm or longer which do not show any "Italian Flag Issues". Lens detection will make no difference in both cases as far as colour shift is concerned.

 

If you use wide angle lenses with UV/IR Cut filters there may be a noticable cyan shift under conditions which stimulate colour shift (my "stress test" in the other examples above represents conditions which are extremely prone to show colour shift). 

 

 

 

 

 

[lct]

[...] With wide angles known to have issues with the "Italian Flag Syndrome" one might get into the dilemma of having either magenta cast (without lens detection), cyan cast (with UV/IR Cut) or UV/IR "pollution" (without filters) - and may decide which to prefer. [...]

 

IR-cut filters can reduce Italian flag on wides as well but cyan shifts are unavoidable to a certain extent in my experience. 

[david strachan]

The trouble with colour edge effects is...it's either or it's not. There is no "half pregnant". I see posts like it's "not so bad" or "it's very minimal".

 

It's a dissapointing effect...but easily corrected. My preference is LR flat field correction. If organised it's a few short steps to have edges perfectly corrected.

 

Or just use B&W...problem goes away.

 

...

[lm_user]

A menu choice to correct cyan corners with use of ir/cut filter would be welcome. It is offered on the M8

 

I seem to be in the minority with my willingness to use filters

Edited September 30, 2018 by lm_user

[adan]

The cyan corners from using IR-blocking filters vary pretty much directly with angle of view (i.e. focal length). As Uliwer's examples demonstrate. Individual lens designs may produce some variation (e.g. 21 Super-Angulon vs. 21 Elmarit vs. 21 Super-Elmar vs. 21 setting on the 16/18/21 Tri-Elmar).

 

Longer than 50mm - no problem at all. Shorter than 50mm - there may be an effect, Shorter than 35mm - almost always an effect, getting stronger and stronger as one works down through 24/21/18/15mm. 50mm exactly, I don't know about (not being a 50mm shooter since the M8, where as a "67mm" lens in terms of FoV, it fell into the safe zone).

 

Basically, with a wider and wider field of view, the lens is looking through the filter at a stronger and stronger "slant angle". At 45° to each side (90° total FoV, or about an 18mm lens) Pythagoras tells us the lens is looking through root-2 more depth of tinted glass and thus seeing a 1.41x (41%) stronger "green/cyan" tint.

 

(Some will say the IR/UV filters use interference rather than green density to block the IR light - which may certainly be true. However, it is clear that angle of view still directly affects whether visible red is subtracted as well. In either case, cyan corners with wider-angle lenses).

 

The same happens with the sensor's IR-blocking cover glass, to a lesser extent, but that is always factored into Leica's in-camera lens corrections.

 

However, Leica no longer expects photographers to use the IR-cut filters on cameras from the M9 on, so there is no longer the option to correct for add-on IR filters. They are considered to be an "M8-only" patch and a thing of the past (except for M8 users adding new lenses to their collection). The good news is that, on the M9/240/10, with 50mm+ lenses, IR-cut filters can be used with no extra corrections needed anyway.

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited September 30, 2018 by adan

[adan]

A menu choice to correct cyan corners with use of ir/cut filter would be welcome. It is offered on the M8

 

I seem to be in the minority with my willingness to use filters

 

Yes, well - see this singer who is staring at me? After the performance, we talked, and he said he kept seeing this big pink disk pointing at him out of the crowd, and though it was an infrared gun sight.

 

https://www.x20.org/product/pas-15-long-range-thermal-rifle-scope/

 

But it was just my 55mm UV/IR filter on a 90 Summicron, reflecting the stage lights. (M8, 2008 Democratic Convention, The Flobots perform).

 

While I was really happy to get full-frame when the M9 came out - I was absolutely ecstatic to get rid of the stupid UV/IR filters.

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[lct]

[...] Basically, with a wider and wider field of view, the lens is looking through the filter at a stronger and stronger "slant angle". At 45° to each side (90° total FoV, or about an 18mm lens) Pythagoras tells us the lens is looking through root-2 more depth of tinted glass and thus seeing a 1.41x (41%) stronger "green/cyan" tint. [...]

 

 

Interesting thank you. This could explain why a WA lens like the CA 21/4 can cause red shift on the M240 w/o filter, cyan shift on same w. IR-cut filter and no significant color shift w. or w/o filter on a crop camera like the digital CL. The internal IR filtration must play also a role i guess since that of the CL is more effective than that of the M240 to a significant extent.

[Advertisement]

Hallo,

Look here: Leica M

[lm_user]

While I was really happy to get full-frame when the M9 came out - I was absolutely ecstatic to get rid of the stupid UV/IR filters.

 

I am not suggesting that Leica change anything that would force the use of filters in all circumstances.

 

As noted above bh orhers, there are circumstances where ir contamination is still sn issue Using ir cut filters in thise situations requires corrections in post or Leica could offer the option to correct in camera like they did on the M8

 

I don’t understand the resistance. We all know digital M cameras are sensitive to ir due to thin sensor filter. Why not offer an option? Nothing would change for those not using filters