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Lee Big Stopper
- Thread starter GMB
- Start date
Shashin
Well-known member
It is IR contamination. Right now I am using Hoya ProND filters that have a Metallic ACCU-ND coating--there are other Hoya ND filters that have a "Pro" designation. I have also moved down to 6-stop ND filter which gives me enough control in all but direct sunlight. And I can see though the viewfinder to compose with a 6-stop filter. The Hoya line goes up to 10-stops. I am finding it easier to control color with this filter.
Taken with a Hoya ProND 64X (6-stop) filter on a Pentax 645D with probably has the same color filter array on the CCD and Kodak sensors are actually more sensitive in the IR as the green and blue sensor pixels increase in transmittance at those wavelengths:
You could also see if an IR cut-off filter helps your Big Stopper. I did this with a B+W ND filter, which helped a little, but B+W 10-stop filters are known for a lot of IR contamination.
Taken with a Hoya ProND 64X (6-stop) filter on a Pentax 645D with probably has the same color filter array on the CCD and Kodak sensors are actually more sensitive in the IR as the green and blue sensor pixels increase in transmittance at those wavelengths:
You could also see if an IR cut-off filter helps your Big Stopper. I did this with a B+W ND filter, which helped a little, but B+W 10-stop filters are known for a lot of IR contamination.
GrahamWelland
Subscriber & Workshop Member
Agreed regarding the big stopper neutrality. IR cut helps - for daytime I'll use the 6 stop Pro Glass ND & big stopper as that has the IR block needed.
I've recently started using the Formatt IRND filters that fit the LEE holders. There's a not inexpensive Joel Tjintelaar kit with 3, 6, 10 stop filters which is ideal for daytime long exposures. Resin vs glass but they are more neutral.
Btw, I assume that you shoot a grey card or Passport card as a reference for WB adjustment? That also helps with the LEE particularly but IR block is important too.
I've recently started using the Formatt IRND filters that fit the LEE holders. There's a not inexpensive Joel Tjintelaar kit with 3, 6, 10 stop filters which is ideal for daytime long exposures. Resin vs glass but they are more neutral.
Btw, I assume that you shoot a grey card or Passport card as a reference for WB adjustment? That also helps with the LEE particularly but IR block is important too.
I would shoot a colorchecker before the long exposure, that will give you a good start on a grey reference.
When I go with the 6 stop LEE ( I don't use the 10 stop very often), I am usually shooting water, so I have a "white" point in the water or "grey" point in the rocks that will be around. After applying the LCC, I then try to get a starting point by clicking on a subject in the photo with the WB tool in C1 or on a point on the colorchecker.
Paul
When I go with the 6 stop LEE ( I don't use the 10 stop very often), I am usually shooting water, so I have a "white" point in the water or "grey" point in the rocks that will be around. After applying the LCC, I then try to get a starting point by clicking on a subject in the photo with the WB tool in C1 or on a point on the colorchecker.
Paul
jotloob
Subscriber Member
I had a quick look to the NISI home page . I will check in more detail tomorrow .
But what I found is , that they claim : 6 or 10 stops . No color cast .
Thank you for the hint .
alajuela
Active member
Hi
An IR cut filter will help
I had a similar problem (stacking ND filters) and Andrea at 2Filter - put me in touch with Ira Tiffen, Below is what he had to say. Address both Vari ND and Single Filters - Stacked or not.
Hi, Phil,
I don't have specific information regarding the IQ 180 and IR bleed. However, for both that camera back and the Canon camera it is likely that when using the stacked grads as you have the results would be better with an IR cut filter on the lens.
The variable ND filter is comprised of dual polarizers. Polarizers of this type are dyed using iodine, which has attenuation in the far red and infrared that is different than the organic dyes used in the ND attenuator and the ND grad. The polarizers don't absorb much above 750 nanometers, but they do a better job than the dyes below that spectral region. That is why there is a difference in the result between the two filter options.
I hope this explains the situation and your results to your satisfaction. If we can be of further assistance, please let me know.
Thank you for your interest in our products.
Best regards,
Ira
AND further
Hi, Phil,
Typically, infrared issues are made worse when using denser neutral density filters. This is because the dyes in these filters are not able to absorb light in the far red and infrared region as much as they do through the visible. The extra light transmitted in this region becomes a larger proportion of the overall the more the overall amount of light in the visible region is reduced, as it would be with denser ND filters. That is why we produce our Platinum IRND filters, which incorporate a special dye component that can handle the far red and infrared most effectively. However, this is not available with either our attenuators or our grads.
You could obtain one of our IRND 0.3's instead of the regular ND 0.3, and it would have the IR absorbing component in it, but it would be only enough to handle the requirements of an ND 0.3, and maybe a bit more. It would not be expected to cover the same range in the infrared as would, say, a True-Cut filter. The True-Cuts come named after the point above which they stop transmitting light, in 680, 720, and 750. The True-Cut 680 starts reflecting light above 680 nanometers, and so is the strongest and most complete elimination of far-red and infrared of the three filters.
It does come with one caveat - that as the strongest, it also produces the most difference in color from the center to the edge of an image the wider the field of view. This is because these filters are interference coatings on optical glass, which have the property of changing their transmission properties with the incident angle of light. As you turn one in your hand looking through it at different angles, you'll see it subtly change color. When mounted on the lens, there will be a certain difference in the angle of transmitted light between the center of the image, where the light passes almost perpendicular to the filter, and the edge, where there is more of an angle.
This difference, of course, increases with wider lens angles. While there is no precise rule, in general you should be okay with these above a 50 mm focal length, and may be okay with the True-Cut 750 above 35mm. Testing is recommended before critical shoots.
I wish that the situation were simpler, but as you know, changing technology, while making some aspects of life today possible, also makes others more complex.
Please let me know how it goes with you.
With best wishes for the New Year!
Ira
An IR cut filter will help
I had a similar problem (stacking ND filters) and Andrea at 2Filter - put me in touch with Ira Tiffen, Below is what he had to say. Address both Vari ND and Single Filters - Stacked or not.
Hi, Phil,
I don't have specific information regarding the IQ 180 and IR bleed. However, for both that camera back and the Canon camera it is likely that when using the stacked grads as you have the results would be better with an IR cut filter on the lens.
The variable ND filter is comprised of dual polarizers. Polarizers of this type are dyed using iodine, which has attenuation in the far red and infrared that is different than the organic dyes used in the ND attenuator and the ND grad. The polarizers don't absorb much above 750 nanometers, but they do a better job than the dyes below that spectral region. That is why there is a difference in the result between the two filter options.
I hope this explains the situation and your results to your satisfaction. If we can be of further assistance, please let me know.
Thank you for your interest in our products.
Best regards,
Ira
AND further
Hi, Phil,
Typically, infrared issues are made worse when using denser neutral density filters. This is because the dyes in these filters are not able to absorb light in the far red and infrared region as much as they do through the visible. The extra light transmitted in this region becomes a larger proportion of the overall the more the overall amount of light in the visible region is reduced, as it would be with denser ND filters. That is why we produce our Platinum IRND filters, which incorporate a special dye component that can handle the far red and infrared most effectively. However, this is not available with either our attenuators or our grads.
You could obtain one of our IRND 0.3's instead of the regular ND 0.3, and it would have the IR absorbing component in it, but it would be only enough to handle the requirements of an ND 0.3, and maybe a bit more. It would not be expected to cover the same range in the infrared as would, say, a True-Cut filter. The True-Cuts come named after the point above which they stop transmitting light, in 680, 720, and 750. The True-Cut 680 starts reflecting light above 680 nanometers, and so is the strongest and most complete elimination of far-red and infrared of the three filters.
It does come with one caveat - that as the strongest, it also produces the most difference in color from the center to the edge of an image the wider the field of view. This is because these filters are interference coatings on optical glass, which have the property of changing their transmission properties with the incident angle of light. As you turn one in your hand looking through it at different angles, you'll see it subtly change color. When mounted on the lens, there will be a certain difference in the angle of transmitted light between the center of the image, where the light passes almost perpendicular to the filter, and the edge, where there is more of an angle.
This difference, of course, increases with wider lens angles. While there is no precise rule, in general you should be okay with these above a 50 mm focal length, and may be okay with the True-Cut 750 above 35mm. Testing is recommended before critical shoots.
I wish that the situation were simpler, but as you know, changing technology, while making some aspects of life today possible, also makes others more complex.
Please let me know how it goes with you.
With best wishes for the New Year!
Ira
alajuela
Active member
Hi
One other bit of information also from Schneider Optics - Which is where Ira is at as VP - really nice guy. .
This morning we were able to check the IR filters with the camera and have come to the conclusion that the IR 680 #68-121156 should resolve the issue. Please note that as you stack densities the problem grows more evident.
Hope this helps,
Thanks
Phil
PS - I also have the Big Stopper - but you might like the Heliopan ND3.0 which is 10 stops.
http://www.bhphotovideo.com/c/product/829010-REG/Heliopan_707789_77mm_Neutral_Density_ND.html
One other bit of information also from Schneider Optics - Which is where Ira is at as VP - really nice guy. .
This morning we were able to check the IR filters with the camera and have come to the conclusion that the IR 680 #68-121156 should resolve the issue. Please note that as you stack densities the problem grows more evident.
Hope this helps,
Thanks
Phil
PS - I also have the Big Stopper - but you might like the Heliopan ND3.0 which is 10 stops.
http://www.bhphotovideo.com/c/product/829010-REG/Heliopan_707789_77mm_Neutral_Density_ND.html
I use the Schneider Platinum IRND filters (4x4" size) and really like them. There is still some IR contamination with the 6 stop filter but it is subtle and easy to correct. The 4 stop filter is very neutral. I sometimes combine the two for extra ND filtration and the results are still very very good. Awesome filters.
I have tried other brand's ND's and the IR contamination can be quite severe with some.
I have tried other brand's ND's and the IR contamination can be quite severe with some.
Presumably these will work with the Lee filter holders ? Or have you bought the Schneider holders as well ?
Thanks.
jotloob
Subscriber Member
I searched the net for that BIG/LITTLE stopper issue and found many entries . The issue seems to be more serious with the resin stoppers and less with ND glas filters . But which one is the best ? ? ?
Also I had a call with HELIOPAN and was told , that a IR cut filter might solve the issue , depending on the digital back and their IR filters in front of the sensor . But also might not bring a solution or only very little .
It seems , that there will not be a 100% solution for the color cast issue with the 6 stop and 10 stop ND filters . Glas filters will be better , that is for sure .
Also I had a call with HELIOPAN and was told , that a IR cut filter might solve the issue , depending on the digital back and their IR filters in front of the sensor . But also might not bring a solution or only very little .
It seems , that there will not be a 100% solution for the color cast issue with the 6 stop and 10 stop ND filters . Glas filters will be better , that is for sure .
Hi, The holder looks similar to the Lee holder but I think it is modified a bit since I believe the Schneider glass filters are a bit thicker. But the design is identical and the adapter rings for the lens filter threads are the Lee rings. (I have the Wide Angle ones).
jotloob
Subscriber Member
I feel very much the same and think , that the LEE Little Stopper was a total waste of money . There are some brands offering glas ND filters , 100x100 mm
and they all claim that their ND filters produce either neutral colors or no color shifts . And these filters are rather expensive . Too expensive for more testing when you can't return the filter if the test fails .
Might be that one and the same ND filter shows different results for PHASE , HB or LEAF backs .
Does anybody have experience with CFV-39 and CFV-50 backs using 6 or 10 stop ND filters ? ? ?
I always just convert to B&W with the Big Stopper because of color issues. I have the Formatt Joel Tjintelaar 3,6,10 stop kit that Graham mentioned above. The attached pic is with my Hassy H4D-40 and the 6 stop IRND from the Formatt JT kit. I can post more examples if anyone would like. I've been meaning to do a side by side test with the big stopper and the Formatt 10 stop IRND for the forum but haven't gotten around to it.
Hi Michael,
Pretty simple: I just hold the WhiBal in front of the lens and expose at the same aperture, shutter speed and focal point as the image. It's of course a blurred image usually with my thumb in it!
In CaptureOne color tab, I'll click on the grey area with the eyedropper. Pretty basic but seems to work well on both my MFDB and Leica. Of course if I'm in very different light than the subject, this doesn't work well and I'll try different areas of the image to find the color balance I want. For landscapes it's more about what I want to show than 99% accuracy as would be desired in the studio...
I'm not a pro, but this seems to work very well for me.
Bob
Pretty simple: I just hold the WhiBal in front of the lens and expose at the same aperture, shutter speed and focal point as the image. It's of course a blurred image usually with my thumb in it!
In CaptureOne color tab, I'll click on the grey area with the eyedropper. Pretty basic but seems to work well on both my MFDB and Leica. Of course if I'm in very different light than the subject, this doesn't work well and I'll try different areas of the image to find the color balance I want. For landscapes it's more about what I want to show than 99% accuracy as would be desired in the studio...
I'm not a pro, but this seems to work very well for me.
Bob