Variable ND problem?

I just upgraded to the Canon 70-200mm f2.8 IS II & Canon EF 24-70mm f2.8L II USM. I purchased a Tiffen 82mm variable ND filter and B/W 82-77mm adapter ring. So yesterday I wanted to do some test shots. With the 70-200 I used a polarizer and the ND filter. Used live view on the 7D and took the first shot. Okay thats looks like it does what it's suppose to do. Then I mounted the ND filter only on the 24-70 and all I got was this blue X image. Is this a defect or did I do something wrong?

It is my understanding that all variable ND filter do this to some degree nearing their darkest limit. How much varies by filter and by your focal length. You'll have more of this effect at wider focal lengths. You can lower the darkness on your filter and use a longer focal length to combat it. This effect is due to the fact that variable ND filters are simply two opposed polarizing filters.

If you are seeing this all the time you may just have a bum filter. There are many tests and a great deal information about this X type pattern to be found on the internet.

carguy4471 wrote in post #16069597
It is my understanding that all variable ND filter do this to some degree nearing their darkest limit. How much varies by filter and by your focal length. You'll have more of this effect at wider focal lengths. You can lower the darkness on your filter and use a longer focal length to combat it. This effect is due to the fact that variable ND filters are simply two opposed polarizing filters.

If you are seeing this all the time you may just have a bum filter. There are many tests and a great deal information about this X type pattern to be found on the internet.

I had the ISO at 800 f/9 at 0.8sec. So try lowering the f stop? Thanks for your quick reply and I'll check into it.

MJEXP wrote in post #16069771
I had the ISO at 800 f/9 at 0.8sec. So try lowering the f stop? Thanks for your quick reply and I'll check into it.

Just curious as to why you would use an ND filter at ISO 800?

gonzogolf wrote in post #16069803
Just curious as to why you would use an ND filter at ISO 800?

This.

Lower the iso to 100 so that you can reduce the power of the ND filter.

carguy4471 wrote in post #16069841
This.

Lower the iso to 100 so that you can reduce the power of the ND filter.

I've never used a ND filter before. Photography is like life I learn by my mistakes. I wanted my photography buddy to shoot with me and he was busy and I just decided to go out and see what I could do as a test run. Thanks for all your comments and help.

I use Marumi ND variable and have the same effect at wide angle.

Apparently variable ND's are notorious for this effect.


http://photo.stackexch​ange.com …utral-density-filter-poor

MJEXP wrote in post #16069875
I've never used a ND filter before. Photography is like life I learn by my mistakes. I wanted my photography buddy to shoot with me and he was busy and I just decided to go out and see what I could do as a test run. Thanks for all your comments and help.

Nothing wrong with having troubles your first run. Everyone starts somewhere. I've used this forum for help countless times and am eternally grateful for all the help I've received. Give the ND filter another run, and another. Keep the iso low and if you are seeing the X pattern lower the filter strength till it goes away.

Check this out:
http://photo.blogoverf​low.com …ariable-nd-filter-review/
The last comment on the bottom of this page says,quote:
"The dreaded ‘cross’ or ‘butterfly’ effect comes when the two elements are not lined up properly. Sometimes that way from the factory, sometimes from repeated use. It’s not difficult to unscrew the retaining ring with a rubber stopper and rotate on element until the cross is gone at maximum ND."

Anyone heard of such a tweak?

Never heard of tweaking anything; that's just the effect you wind up with at wide angles with the variable NDs.

It's one of the reasons (for me, anyway) for moving from the variable ND to graduated NDs and a CPL when appropriate. You can stack the NDs to get multiple levels of light reduction and they don't "crosshatch" no matter how dark you make the stack or how wide you're shooting.

I still hold onto my variable for some situations, but those are pretty few and far between.

The Marumi ND's that I have are the DHG ND 2 - ND 400 67mm and 58mm.

The outer ring rotates freely all the way around so I do not understand the idea that they are misaligned and would require a tweak.

Even the very best variable NDs (probably the Singh-Ray) tend to do some of that.

It's a good argument for only using quality, standard (non-variable) NDs in a few different strengths.

Note that a variable-ND might be specified as 10-stop. But when you turn it, it might actually allow up to 13 stops. So why wouldn't it be specified as 13-stop? Simple - because up to 10 stop is where it works well - after that it starts to get this moire effect. This is an expected result when you continue past the maximum supported filter value - don't you have some markings on the filter that describes the supported range?

There is nothing wrong with the filter.

pwm2 wrote in post #16070195
don't you have some markings on the filter that describes the supported range?

The Marumis do have markings showing min and max densities. I do not use the filters very often, but when I have, they have served their purpose well enough.

I just do not use them below about 50mm on the 17-85mm lens.

It's a known effect of variable NDs. There's nothing wrong with your filter. Singh-Ray has a notice on their website that the X occurs near its maximum setting and that even though you can set it very dark, you shouldn't because of the X. Don't worry about it and lower the setting.