Any other problem besides magenta cast if not using IR filter?

ckuang

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Hi everyone, I finally bought myself a second hand leica m8 after years of agonizing. I bought the leica m8 with the intention of only shooting black and white on it and was just wondering if there was any problems besides the magenta cast if I did not put an IR filter on my lens.

Ie, is does the image appear softer as a result of not using the filter? the reason why I'm asking is because i faintly remember reading somewhere that besides eliminating the magenta cast, the filter also did something along the lines of reducing CA or something like this which helped to maintain sharpness in the image. Or did I sinmply imagine that i read something like that? Any info would be really appreciated before i commit to spending a whole lot on IR filters for which I don't really need since I was only going to shoot black and white.

oh and a little OT, but was wondering if anyone knew why the I should buy the leica summicron 28mm over the Voigtlander Ultron 28mm f2.0? Any opinions would be really appreciated. thanks.
 
The only thing I think could possibly have an effect is that without filters you reach into the infrared range.

I strongly suspect that the red shadows I got when photographing lost villages in Spain was due to relatively hot walls and dark shadows in combination.

Have heard others say that this effect is a bonus when converting to BW!
 
jbf, I feel for you; having the wisdom teeth out is no fun at all

For a discussion with some comparisons among the two 28mm Ultrons and the 28 Summicron, take a look at Reid Reviews, a subscription site at http://www.reidreviews.com/

He seems to think the previous 1.9/28mm Ultron has some advantages over the new 2.0. The Summicron gets good comments, perhaps overall preferable to the Ultrons, but then it isn't always a matter of better or best, but rather a matter of which advantages are more important to you.

I have the 28 Summicron, a great walkaround single lens for the M8. I haven't had either Ultron, but the little Voigtlander 3.5/28mm Skopar is a gem.
 
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Thanks for the advice guys, yes, I kinda figured leaving the IR filter off would give a little more shadow details in the B/W and what i've tried in color so far hasn't been out of focus. well a little front focusing but i think it has more to do with the cam than the filter.
 
Personally I have the old CV 28 Ultron and it's amazing. Though that could be the pain killers talking from my wisdom teeth begins sucked out of my face.

In any case though, the ultron is amazing I think. Film or digital, it's great:

http://www.flickr.com/photos/sarky_coolbox/tags/voigtlanderultron28mmf19aspherical/page1/

The strong contrast on my film images is due to the processing methods.

I think the strong contrast works very well in these shots. I wouldn't change a thing.

Harry
 
Hey JBF, thanks for sharing your gallery. Yes, love the black and white stuff shot on Tri X and the Ultron 28mm. The scanning was also pretty good. Did you scan it yourself or have it done by a lab?

Regarding the IR-UV cut filters, does anyone know if the Leica ones are the only way to go? There are some from Heliopan and B+W which are significantly cheaper and I was wondering if those work as well as the leica ones.
 
Theres been a thread on the different filters - from what I recall the Leica ones are just a tad better. Or was it the other way around?

I have collected second hand leica filtes myself - besides the B&Ws that I got with the M8. Most pictures that I took before getting filters where sort of acceptable after photoshopping - but I would not keep on without. I have had purple clothes and faces on people in broad daylight actually, although that is luckily not the norm. Indoors though can be as bad as not being editable...
 
In color, without the IR filter, you get yellowish grass and foliage as well as the IR cast. There are also all sorts of subtle color shifts that may not matter much, but they are there. In tungsten light, caucasian skin looks paler and "pastier." The problem is *not* just with black synthetic fabrics.

I am a believer in the fact that pictures are sharper and contrastier with the IR filter than without it, even in B&W. Especially in tungsten light. See the following side-by-side comparison:
http://users.2alpha.com/~pklein/temp/IRNofiltVsFilt.jpg

I've tried this kind of comparison several times, and gotten the same result. And before my IR filters arrived, I liked my photos less than after I started using them. So while you might dismiss the above pictures as unscientific, I have seen the effect far too often to ignore it. I therefore use IR filters almost all the time.

B+W filters are fine, that's what I mostly use. I put my free Leica filters on my widest lenses.

In a very dark, tungsten-lit setting, 1/30 or 1/15 (or slower) at f/1.4 territory, you might gain a half-stop of shutter speed without the IR filter. It might gain you more than the sharpness you'll gain with the filter.

--Peter
 
Peter,
Your findings are exactly my own.
I do use one lens consistently without filter for color and B&W, and that is my 1st version tri-elmar 28-35-50 (mate) because the shifting front element creates a pretty good hood and using the IR filter plus hood turns this lens into a clumsy monster very prone to veiling flare.
I can easily correct magenta clothing and yellow grass and trees with a custom profile which I make with the Adobe DNG profile editor for ACR/Lightroom or making a profile in Capture One. The NIK Viveza plugin also works pretty well.
Maurice
 
hmm never though about losing speed, but certainly sounds like a possibility. So is the jury out? filter even for B&W?
 
I think you'd want to experiment for your own satisfaction whether you prefer black & white conversions with or without the IR Cut filter...

This is B&H's product description for a B+W 486 Digital UV/IR Blocking Glass Filter:

This B+W 486 Digital UV/IR Blocking Glass Filter has a completely colorless Schott glass carrier coated with a number of extremely thin, partially reflecting layers with precisely computed thicknesses, similar to MC coating (multi-coating).

The B+W Filter 486 does not block by means of absorption, but by interference of the unwanted UV and IR radiation that is repeatedly reflected between these layers affecting the wavelengths on both sides of the visible spectrum with a steep cut-off.

• Used mainly on digital and video cameras with CCD sensors without an integrated IR protection filter, because the IR sensitivity of the CCD sensor would otherwise cause color changes and unsharpness.

• That unsharpness results from the chromatic aberration of the lenses that are only corrected for visible light.

• In the visible range, the transmission curve is very high and straight.
 
What!? you lose speed with an IR filter?

No, but you might gain speed by not using them ;)
Because the shadows are more open and faces are whiter due to the IR sensitivity you can in some situations use at least an extra -1/3 or -2/3 of exposure compensation.
After using the M8 for over 2 years almost solely for B&W i am still not sure if i prefer the files with or without IR filter ...... i tend to prefer them without IR filter and proces from there! The files without IR filter are certainly less contrasty and therefore look less sharp .... but after proper processing of the raws i never ever had any sharpness issues with the files shot without IR filter. I never did comparissontest ... but IF there is an effect on acual sharpness ... it is purely academic at best .......
 
There's conjecture that the IR filter makes a [color] image sharper. Personally, I don't buy it. The thought is that since infrared wavelengths focus at a different point than the visible wavelengths, there will be a sort of "out of focus image" in there. By using the IR filter, you eliminate this "ghost." Similarly, this is supposed to add a little "extra" to black and white images.

The filter definitely helps with color accuracy, especially the magenta issue.

It is not conjecture. The IR part of the image is definitely out of focus with most lenses (not all - the Apo-Summicron 90 asph is corrected to well into the IR part of the spectrum for instance), and on average it is about four to five stops underexposed, which is well within the dynamic range. On longer focal lengths CA is a consideration too.Whether it makes any important difference in the final print depends on many other factors, and must be judged by every user for himself.
 
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What!? you lose speed with an IR filter?

Hi there kipkeston
Looks to me like the B+W 486 has about 80% average transmission.

I still can't get over that little bit of overhang into the IR on the KAF chip giving so much grief.

At 690nm there's hardly anything on the spectral response chart. But I've seen the magenta results posted here. :(

I will soon experience this for myself. Getting my M8 within days.
This forum rocks BTW.

Cheers :)
 
Looks to me like the B+W 486 has about 80% average transmission.
98 % in the visible light; the filter factor is 1. That goes for Heliopan and Leica too. See the Schneider and Heliopan websites and transmission curves.
 
98 % in the visible light; the filter factor is 1. That goes for Heliopan and Leica too. See the Schneider and Heliopan websites and transmission curves.


I got this info from the only "transmission curve" graph I could find at the B+W site for their 486 UV-IR cut filter.

I must be interpreting their graph wrongly.
 
I got this info from the only "transmission curve" graph I could find at the B+W site for their 486 UV-IR cut filter.

I must be interpreting their graph wrongly.
The filter factor is 1. That is in the PDF. A filter of 80% would have a factor of 1.2.(approx)
 
I suppose it filters away 20% of the total light, including the IR which it should filter of course... The 2% loss is in the visible range, which is what we want preserved and hence the filter factor of 1?

Never thought about the possibility of really getting shadow detail from IR, but it seems to make sense in dark & relatively warm places! Will try to check it on say a sun-warmed floor as soon as summer sets in...
 
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