Red problem !

[Tim Polster]

All I can say is Wow.

[Leonard Levy]

Bob,
How happy are you with the 486 filters on your EX-1's. Do you have problems with green vignetting when wide and di you keep them on all the time?

Lenny Levy

[Sean Donnelly]

I've been using a 486 behind a Letus for several weeks now, and have not noticed any problems. Without the Letus and below 12mm or so I see a faint green/cyan cast on the edges. This is not always visible, but high key flat surfaces will definitely show it (white walls for example). It can be pulled out with a secondary adjustment in Color, however I'd rather not have to go through that step, and it changes size and shape so it will not always be the same each time otherwise a shading adjustment could resolve it.

Tim, if you call back ask for Lou. I've spoken to him twice about this subject and referred him to this thread. He has heard of a few cases of it, and seems to be concerned with getting it resolved.

-Sean

[Piotr Wozniacki]

Yes, I can confirm that using the 486 between the Letus achromat and the EX1 lens doesn't pose any additional problems than using it as the outermost optical element (at least, I personally don't see anything apart from the same green tint; in fact it tends to happen less often with Letus as you don''t use the widest angle).

[Ryan Avery]

Originally Posted by Leonard Levy

Ryan ,
I don't know why I continue to be confused, maybe there is a language problem or perhaps I'm dense.
I am very concerned about the inability of the 486 to deal with wide lenses. I would not want to purchase anything so limited.

Yet in the post above you say that the 489 is good for lenses with less angle of view. Those ideas sound contradictory. Which filter is better for wide lenses?

I don't understand why you are saying the 489 is not good if placed in front of lenses. Is the only problem a slight green cast or is there also a wide lens issue? Does its greater IR reduction have a bad side affect.

Lenny Levy

Ok, let me set everyone straight here.

There are two factors at play here in adding to everyone's confusion. One, the original post I made regarding the 486 vs 489 filters information is all true but based on information that I had at the time. The 486 is better for telephoto applications and normal angles (ie, 50mm in 35mm sensor size). The 489 is better for applications closer to the sensor but will still add a green cast if wide angle lenses are used. This is due to the reflective properties of the 486.

Two, I have failed to explain how this technology works. 486 and 489 filters are designed to cut off IR light at 680 nanometers. This is in the near-visible IR spectrum and therefore sometimes visible to the camera's sensor. When you cut off IR light this low in the spectrum, the angle of view that will not cause color issues is significantly reduced. Our new True-Cut IR 750 cuts off the light at 750 nanometers. This is still on the edge of near-visible IR light; the outer edge. We have discovered that this will work at the widest angles possible while still maintaining the IR cutting properties required. This is information that has come to me recently.

Therefore, the 486 and 489 filters were the only solution we had to work with by adapting older photographic technology to video. We have since recognized these short comings for video applications and produced the True-Cut IR 750 filter. Most video application should use the True-Cut IR 750 filter on the outside optical element. Use of this filter internally can create internal lens reflections resulting in flair and CA. The 489 is the only workable solution for this scenario but limits you to narrower angle of view.

Ryan Avery
Schneider Optics

[Ray Bell]

Ryan, Can you post a part number for the ir750 filter...

I couldn't find it on your site...

[Leonard Levy]

Ryan , what I'm confused about still is whether the 489 adds an overall green tinge (which I could probably filter out) , or whether it is like the 486 in only adding the green around the edges which is a big big problem.

How much is the True-Cut IR 750, and where can we get it?

Lenny Levy

[Ryan Avery]

Originally Posted by Ray Bell

Ryan, Can you post a part number for the ir750 filter...

I couldn't find it on your site...

Here are the stock codes and pricing for the True-Cut IR 750;

68-121044 4" x 4" True-Cut IR Filter $295.00
68-121056 4" x 5.65" True-Cut IR Filter $395.00
68-121057 5.65" x 5.65" True-Cut IR Filter $550.00
68-121059 5" x 5" True-Cut IR Filter $550.00
68-121066 6" x 6" True-Cut IR Filter $595.00
68-121077 77mm True-Cut IR Filter $250.00

All prices are list prices in USD. Check with a dvinfo sponsor for discounts.

Ryan Avery
Schneider Optics

[Ryan Avery]

Originally Posted by Leonard Levy

Ryan , what I'm confused about still is whether the 489 adds an overall green tinge (which I could probably filter out) , or whether it is like the 486 in only adding the green around the edges which is a big big problem.

How much is the True-Cut IR 750, and where can we get it?

Lenny Levy

The green cast (overall vs corners) has to do with the nanometer cut-off of the filter and the angle of view your lens produces. The wider the angle of view, the more green will show up. The 489 was designed for industrial applications where color is generally not an issue. The only filter that we sell which was designed specifically for your video camera is the True-Cut IR 750.

You can use the 489 and 486 filters but as we have seen through extensive back and forth conversation, these filters are best for industrial and photographic applications and should be used only as a last resort for video applications. I suggest you use the True-Cut IR 750 and find a way to attach it to the front of your camera.

Ryan Avery
Schneider Optics

[Piotr Wozniacki]

Originally Posted by Ryan Avery

Therefore, the 486 and 489 filters were the only solution we had to work with by adapting older photographic technology to video. We have since recognized these short comings for video applications and produced the True-Cut IR 750 filter. Most video application should use the True-Cut IR 750 filter on the outside optical element. Use of this filter internally can create internal lens reflections resulting in flair and CA. The 489 is the only workable solution for this scenario but limits you to narrower angle of view.

Ryan Avery
Schneider Optics

Dear Ryan, could we take for granted then, that using the True-Cut IR 750 filter is absolutely free of the green tint problem?

Cuase you see, I don't feel like spending any more cash on a 4th B+W filter in a row...

[Leonard Levy]

With all respect to Ryan who has been trying to help us a great deal on this forum, I am finally beginning to suspect perhaps Schneider doesn't want its representative to say anything that could be construed as negative about its filters. I don't quite get it, but perhaps this is a typical business policy - certainly we haven't seen Sony making any announcements about back focus problems or even vignetting except very indirectly. They'll fix it but they haven't announced any recalls.

I think we've been hoping to get a clear statement from Ryan somewhat like :
If you use the 486 on an Ex-1 you will get green vignetting under "x" circumstances, other possible issues are x y and z.
If you use the 489 etc.
and now of course - "if you use the True-Cut IR 750 you will or will not get green on this or that circumstance.

That's all i want to know - exactly what it will do on an EX-1 and if there are any other issues we should know about ( i.e. stacking with other filters, compatability with say a pola, or daylight vs. tungstun, any color casts etc.

I am far less interested in knowing why it was developed.

So let me try this again.

--Is it true that there may be some green vignetting on an Ex-1 with both 486 and a 489 at wide angles and that there will not be any green vignetting or other color problems with the True Cut 750?

--Also Is it OK to stack the Tru Cut 750 within other filters?

-- Any other issues we should know about with the True Cut. ? Will a 77mm fit inside the EX hood? (that's a tough one).
---Is the coating any more subject to abrasion?
---Can you use this as a general protection filter all the time in your shooting?

Thanks,

Lenny Levy

[Piotr Wozniacki]

Originally Posted by Leonard Levy

So let me try this again.

--Is it true that there may be some green vignetting on an Ex-1 with both 486 and a 489 at wide angles and that there will not be any green vignetting or other color problems with the True Cut 750?

--Also Is it OK to stack the Tru Cut 750 within other filters?

-- Any other issues we should know about with the True Cut. ? Will a 77mm fit inside the EX hood? (that's a tough one).
---Is the coating any more subject to abrasion?
---Can you use this as a general protection filter all the time in your shooting?

Ditto. let me only add one question:

---What is the Tru Cut 750 real light transparency coefficient (as compared to the 486's 1.0 and the 489's 1.2)

[Ryan Avery]

Originally Posted by Piotr Wozniacki

Ditto. let me only add one question:

---What is the Tru Cut 750 real light transparency coefficient (as compared to the 486's 1.0 and the 489's 1.2)

1.1

Ryan Avery
Schneider Optics

[Ryan Avery]

Originally Posted by Leonard Levy

--Is it true that there may be some green vignetting on an Ex-1 with both 486 and a 489 at wide angles and that there will not be any green vignetting or other color problems with the True Cut 750?

--Also Is it OK to stack the Tru Cut 750 within other filters?

-- Any other issues we should know about with the True Cut. ? Will a 77mm fit inside the EX hood? (that's a tough one).
---Is the coating any more subject to abrasion?
---Can you use this as a general protection filter all the time in your shooting?

Thanks,

Lenny Levy

1) The 486 and 489 filters have the possibility of creating a green cast at the edges or all around the image at wide angles and certain angles of light source, or both. I am not certain how much more clear I can get that it was developed for industrial and photography applications, not video. The True-Cut IR 750 was developed for your video camera. The True-Cut IR 750 should not create a green cast on your images on lenses above 10mm in 35mm motion picture lens terms and above to 3mm on 1/2" cameras.

2) Yes you can stack the True-Cut IR 750 with other filters but it must be the first filter the light hits. Ie, front of the mattebox.

3) Yes our 77mm True-Cut IR 750 filter will fit inside the hood. I tested it on 4 different EX1 cameras. No other issues that I am aware of or have not been beaten to death in this forum. :)

4) Yes the coating is more subject to abrasion

5) Yes you can use it as a general protection filter but be aware that you are more likely to scratch it than one of our MRC coated filters. However, I have a sample I have carried around in my bag to various sets and I have yet to scratch it after many cleanings and knocking around. Not a guarantee but my personal experience.

Ask a direct question; get a direct response.

Ryan Avery
Schneider Optics

[Leonard Levy]

Thanks Ryan,
That settles it all clearly for me , Sorry I was dense before.
I appreciate your hanging in there.

Sounds like something we should all have for the Ex-1

Lenny