Red problem !

[Ryan Avery]

Originally Posted by Ryan Avery

Based on the discussions here and my knowledge of both filters, I would think that the 486 would be the better choice. I do not have direct experience with the set up you are talking about but from a science aspect the 486 is the proper filter.

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

[Christopher Barry]

Ryan,

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

Thanks.

[Piotr Wozniacki]

Originally Posted by Ryan Avery

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 avoid 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

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?

[Michael Maier]

Originally Posted by Piotr Wozniacki

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 :(

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.

[Piotr Wozniacki]

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!

[Mike Stevens]

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

[Piotr Wozniacki]

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.

[Mike Stevens]

Originally Posted by Piotr Wozniacki

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.

[Sean Donnelly]

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

[Mike Stevens]

Originally Posted by Sean Donnelly

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.

[Bob Grant]

Originally Posted by Mike Stevens

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.

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.

[Sean Donnelly]

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.

[Sean Donnelly]

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

[Mike Stevens]

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.

[Leonard Levy]

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