Interesting tests by Adam Wilt:

http://provideocoalition.com/index.p...lter_tests/P0/

This is not the first such tests I've read of, interestingly all camera seem to have these issues to varying degrees. The other not public tests found that cameras such as the Varicam can need an external IR cut filter.

Thanks Bob for the link - what Adam is showing as the adverse effects of the 486 on EX1 at full wide, is nothing compared to the ugly cast in my grabs posted here earlier!

As I said - all depends on many variables, but having a filter like this handy is a must with the EX1.

The green casts and vignetting have nothing to do with the 486 filter. Piotr has something else going on or the filter is bad or is mounted wrong. As I said, the only down side is a slight muting of the reds that I somewhat corrected with a green to Red +15 in the matrix.

C'mon, Mike. While I picked those ugly pics on purpose, the green cast is a fact, confirmed by the filter manufacturer.

In 90% of my shooting scenarios, it's a non-issue at all - so it's possible you have just never noticed it. Especialy that - afaik - yours is not directly on the lense, is it? By increasing the distance (e.g. mounting it in the matte box), you're avoiding the critical incidence angle.

The 486 and 489 alter IR light differently. The 489 will absorb the IR light but only affects this end of the spectrum. The 486 reflects the IR light within the layers of the filter and therefore also controls the UV contamination which will affect blue and green casts to your image. The sensitivity of digital sensors to UV light is much less than the IR light. Therefore a 489 should be relatively as effective as the 486 but for the fact that UV sensitivity still exists with digital sensors and this could be what you are getting with your lens set up.

In mounting the filter, the sequence is very important. A 486 filter reflects the light and there for should be used in the front of all elements. If you are mounting the 486 internally then the issues you state could be happening. The 489 is a better application for internal use such as the situation you state. It is better to have no UV filtration in the 489 and aviod the internal reflection problems.

In short, for this application only, use the 489 internally OR put the 486 in front of the 35mm lens.

Ryan Avery
Schneider Optics

I obviously thought about this one a little more and the above post relates that the 486 is the best filter to use but not for the sequencing of filters used in this particular application.

Ryan Avery
Schneider Optics

Ryan,

A 486 filter available as a 4x4 for MB use?

Thanks.

Dear Ryan,

What a pity you confirmed my concerns only after I have bought another 486 filter (this time, the one with double thread to replace my current 486 SLIM version) - should you have answered two days earlier, I'd go with the 489 as I currently am not using a matte box :(

But never mind; I'll replace it again should need be. However, the following afterthought crossed my mind when reading your answer:

If indeed the reflecting 486 filter type should always work as the outermost (i.e. the first in the stack) optical element, why does its double-threaded version exists in the first place? Having the thread at the front side, it suggests screwing some other optical element into it is conceivable, after all...

Or maybe this is just for some non-optical element, like a sunshade of some sort?

Nevermind that I said like a dozen times the 489 was the right one to use behind a 35mm adapter and that I got that info from somebody at Schneider and have bought the 489 and it is working great with 35mm adapters.
You can just figure that on your own just by reading how both filters handle incoming IR actually. But I tried.

Yes Michael - I know you said it, but a couple of persons using the 486 said it was also working OK, and Ryan of Schneider even mentioned the 486 is "a better choice for this application"... :)

But of course I'm far for blaming anybody but myself for this decision. Since my new 486 provider has the 489 as well, I'll be trying to swap them - he might go for it, if I pay the shipping costs. Before I do however, please answer my other question I also was asking earlier in this thread:

- does the double-threaded 489 filter fit under the stock lens hood, when Letus is not used?

Thanks in advance!

Piotr:
ONLY slim-lines fit under the stock sunshade. That is why I needed to put together the adapter ring arrangements that Schneider complemented me on. See details above somewhere. Slim-lines do not have front threads so the answer to your question is NO

Wrong again, Mike:

http://www.dvinfo.net/conf/showpost....&postcount=122
http://www.dvinfo.net/conf/showpost....&postcount=132

- I have no reason not to believe Peter; anyway I will check it with mine which should arrive soon.

Piotr: Maybe you are addressing MM, but if you are addressing me I assure you the B+W 486 IR/UV slimline does not have a front thread. (Don't be misled by the B&H site that says it does. They are wrong). Now some other fatter IR filters will have a front thread but I do not know of one that can fit under the Sony head. The link you referred to is addressing the slimline with no front thread.

I'm using a B+W 486 filter with front threads. It fits under the hood. I also have put a pola in front of that with no problems. I'll be doing thorough tests with a letus and this filter next weekend.


-Sean

What is the model number? I could not find one and B+W told me not one in their catalog. Be interested to know. It's good though its all a bit academic as I would think with a camera of this sophistication you would have a matte box. Had to do what I did because I have the Cavision clamp on as I did no want the weight of rails.

It's likely that not all 486 filters are created equal. Some say the standard 486 will fit under the hood and no doubt they're correct. But the ones the local agent has in stock sure don't. I know, I tried, hard.

http://www.bhphotovideo.com/c/produc...tal_UV_IR.html

I actually got mine form a different supplier because I needed it quickly and B+H didn't have it in stock.

Hope this is okay to post, but this is Schneider's description of how the 486 works:

http://www.schneideroptics.com/ecomm...D=677&IID=4397

"This B+W Interference Filter has a completely colorless glass carrier coated with a number of extremely thin, partially reflecting layers with precisely computed thicknesses, similar to MC 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..."

Just wanted to put that out there. It sounds to me like it's not reflecting IR back outward, but creating interference which stops it. The Phantom HD which I use quite often has a similar filter ("reflective" type) bonded to the sensor assembly, which now has a low pass filter in front of that and behind the lens. I have never seen any problems with that system, and have exposed it to some extreme amounts of IR (75,000 watts of tungsten light in a 4' area). The absorption filters I believe are more effective, however I don't like the light loss or color shift that needs to be balanced out.

-Sean

A lot said about the 486 but screenshot comparisons so here is desert landscape taken on a moderatly hot day with and without the 486. Camera setting of course were exactly the same for both shots. The "greener" snapshot is with the 496.

Sean (or anyone else for that matter) , does your B+W filter produce the green vignetting at wideangle under tungstun that Piotr showed?

I'm still trying to get a clear answer from people's experience as to how bad this is, and whether it is endemic to all of these filters.

Sure would like to see a few shots of a relatively flat grey scene, under tungstun, iris wide open (usually shows more problems) that shows how bad this is at full wide and when the problem disappears.

Mike,
Do you see a radical difference between the desert shots? Aside from the minor color balance issue, to me the 486 has more contrast but nothing I couldn't fix with a minor tweak in post. Am I missing something?

Lenny Levy

Mike

What Picture Profile are you using for those shots?

Lenny:

From the two shots I posted you can see how the greens clean up. I did one panorama from a hill to over-looking a desert on a very hot day and all the green bushed were really brown and it was beyond what post could do. That's why i got the filter. If you are not in a very hot environment you wont see much difference. In fact, when it is not radiating great heat from the ground I take the filter of and use a UV/Haze.

George:

I'm not 100% sure but I am 95% sure it was Cine1 with the cinema matrix and the master black level set to about -25.

Check this out. We gave some of these in 4x5.65 size to Art Adams and he did some interesting tests.

http://provideocoalition.com/index.p..._filter_tests/

This indeed confirms the use of the new True-Cut IR filter (486 less the UV filtration) as a good use for RED cameras only when extra ND is applied as well as regular HDV cameras with no filtration at all.

Ryan Avery
Schneider Optics

Again, sorry about that comment. I neglected to look at your application carefully. The 486 is the proper filter if its the first optical element in the chain. If not, then use the 489.

The double threaded version exists for non-optical applications like lenshades. Our Industrial Optics division might have another application but I am not aware of it.

Ryan Avery
Schneider Optics

OK: This is my set-up with ND before and aft. Starting from the CDC I have:-

1. Internal ND
2. Camera Lens
3. 486
4. ND in Matte Box
5. Graduated Filter.

Is my 486 the right choice?

Ryan,

Nevermind, everything is not lost yet :)

Tell me please one thing: does the 489 filter model create the green cast near the corners/edges due to the IR angle of incidence like the 486, or is this effect weaker, or stronger?

Since Ryan is not answering, I'd like to ask the 489 filter users for posting some grabs of their shooting in tungsten / incandescent light, and at the full wide EX1's zoom. Does it also produce the green cast near the edges, like the 486 does? I can still replace my new 486 filter (the double-threaded version this time, which indeed fits under the stock lens hood, and can accept the Letus without detaching) with its 489 version, but - before I go for it, and loose money again - I'd like to be certain it's worth it this time :)

BTW, my new 486 works exactly the same with and without the Letus over it - i.e. the adverse affects are there with Letus but only under conditions they would be there without it, as well. At least so far, I didn't notice any additional contamination resulting from closing the filter between my EX1's lens and the Letus' achromat...

which one to get
 

I have just the camera... no matt boxes
I would just put this on the lens...
486 or 489?

486 will be enough.

Piotr
If yours fits under the stock shade do you want to sell yours I read your post about buying the other one...
if so email me
ramvideo!optonline.net

Ryan, Is there any reason not to just go with a 489 as general purpose in front of other elements or in the middle?

- Lenny Levy

Ryan, Is there any reason not to just go with a 489 as general purpose in front of other elements or in the middle?

- Lenny Levy

Lenny,

The 489 was designed for industrial optical applications where it would be placed in between optical elements; preferably nearest the sensor. The 486 has more coatings and is more efficient at blocking IR light. As a side benefit, the 486 also blocks UV light. The downside, as discussed, is that it should not be used in between elements due to the remote chance that the filter can reflect light in certain light angles and cause issues inside the lens. Hence we recommend that you place it on the first element of the lens so that reflections do not harm the image.

Use the 486 unless you are placing it between elements but keep in mind that using the 486 in between elements may not have an adverse effect on your image because of the remote chance of the reflection issue occurring.

Ryan Avery
Schneider Optics

Ryan,

Good to see you here again :)

Tell me please one thing: does the 489 filter model create the green cast near the corners/edges due to the IR angle of incidence like the 486, or is this effect weaker, or stronger?

Piotr,

I have been out travelling on business so I haven't had the chance to participate in the forums like I had hoped. But I'm back!

The 489 should create less green cast that is possible (remotely so) than the 486 at certain angles of incidence from light sources. The 486 is still a better application due to its efficiency when not directly next to a sensor. It seems in your application that it may make a difference but most users do not report these effects.

Ryan Avery
Schneider Optics

You are probably OK. If you don't expereince any green casts or other image anomoly then you are likely not to in the future. It all depends on the angle of light entering your lens. In this case, it seems to be working fine. If you can, I recommend you move the 486 to the front of the lens. If not, then don't sweat it if the results are good.

Its like my car, the manufacturer recommends I put premium fuel in it. I put regular and it runs fine. Should I put premium fuel just because the manufacturer says so? Probably but my results are satisfactory so I don't lose sleep over it. I probably just made some gear-head out there cringe but its the truth!

Ryan Avery
Schneider Optics

So... is there an easy way to compensate for this in post? I shot a graduation with an EX1 and an XHA1. On the Canon, the caps and gowns look black... Not so much on the EX1.

I'm using Axio / PPro 3. Any suggestions to help them cut together more seemlessly.

Once IR light has contaminated an image, it is in there for good. You would have to affect all of your black levels in post and everything would look oversaturated and no details. It would look like you took a black marker to everything.

The 486 filter or the new Schneider True-Cut filter (the 486 minus the UV for less internal lens reflections) would solve this problem.

Ryan Avery
Schneider Optics

Ryan

If I understand you the 489 77mm filter would be used when using a DOF adaptor such as the Letus and the 486 true cut when just using the camera without any other adaptors.

What is the model of the 77mm 489 that has threads on both sides?
What is the model of the 77mm 486 trucut?

Thanks

Chuck