# Red Shift, How easy to correct? (Caused by a filter)



## tspear (Oct 15, 2016)

So I am looking at getting a new neutral density filter for long exposure shots (specifically for beach/ocean). 
The issue is the reviews of B+W MRC 110M Solid Neutral Density 3.0 Filter, the filter causes red shift. 
My second choice (Hoya) does not have the multiple coatings and in reviews has issues getting cleaned. 

So my question is, how hard to correct for the red shift and what is the best method in Lr?


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## Johan Elzenga (Oct 15, 2016)

Providing that the shift is really equal over the entire image, it shouldn't be too difficult to correct with White Balance (temp & tint). Another possibility is to do it with HSL or with the red channel in Curves.


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## johnbeardy (Oct 15, 2016)

I use Lee's 10 and 15 stop filters and only need to use WB to correct. One little tip is to take a test shot without the filter. You probably will take this extra shot anyway, just to focus and compose, but keep it and use it in Lr to guide your colour correction.


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## tspear (Oct 15, 2016)

JohanElzenga said:


> Providing that the shift is really equal over the entire image, it shouldn't be too difficult to correct with White Balance (temp & tint). Another possibility is to do it with HSL or with the red channel in Curves.



Yes, based on reviews it is even in the shift. I can handle the White Balance, but I think when I order this lens I need to step up my game and learn how to use the curves  I have played with them but never really used them and do not understand it yet.



johnbeardy said:


> I use Lee's 10 and 15 stop filters and only need to use WB to correct. One little tip is to take a test shot without the filter. You probably will take this extra shot anyway, just to focus and compose, but keep it and use it in Lr to guide your colour correction.



I like the idea of the test shot to compose it. 15 Stop? Kinda cool, I have not seen any that dark. I have an existing 6 stop which I figured combined with the 10 stop would handle most of the daylight ocean shots I am trying to do. If not, I will just have to look for a 15 or just combine more filters....


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## johnbeardy (Oct 15, 2016)

Tim, once you have one of these filters, you'll wonder how one can ever compose without a test shot - after all, you can't see through 10 stops, and the camera can't get a reliable exposure! 15 is relatively new, intended for shooting extreme long exposures in daylight.

A couple of other tips:

Triggertrap allows you to dial in long exposures (ie > 30 seconds) 

Triggertrap also has a built in exposure converter that makes it easy to convert your test shot 1/20 to whatever is needed with a 10 or whatever stop filter.
Be careful to close the viewfinder - light can leak through and cause odd streaks or patterns 

I usually combine these filters with a neutral grad, so I prefer rectangular filters like Lee
Rectangular filters work better if you have a few lenses


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## tspear (Oct 16, 2016)

John,

Thanks for the tips. I am actually getting Pulse as a gift (Pulse : Wireless camera controller and remote trigger) in a few weeks; I hope, it has been back ordered for over a year.
So far I only have a few filters and two lenses. I have found the Sigma 35mm prime is really my goto lens and I actually rarely use the telephoto lens now; compared too when I really started two and half years ago I almost only used the telephoto lens.... As a result, I expect I am going to "waste" and duplicate buy stuff as I learn.


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## PhilBurton (Oct 16, 2016)

johnbeardy said:


> Tim, once you have one of these filters, you'll wonder how one can ever compose without a test shot - after all, you can't see through 10 stops, and the camera can't get a reliable exposure! 15 is relatively new, intended for shooting extreme long exposures in daylight.
> 
> A couple of other tips:
> 
> ...



Judging only by the product description on the website, Triggertrap is amazingly cheap for what it does.

Phil


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## johnbeardy (Oct 16, 2016)

PhilBurton said:


> Judging only by the product description on the website, Triggertrap is amazingly cheap for what it does.



It's the phone that's the expensive bit, Phil. Essentially Triggertrap is a well-designed iOS app with generic connection cables.

John


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