ND Grad vs Circular Polarizer?


Cam0909

New Member
Jan 21, 2010
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#1
I am keen to purchase a Hi-Tec 0.6 ND grad (soft) , with an interest to shoot landscape/water shots etc. However, I also read from various sources that a Circular Polarizer (CPL) is recommended for landscape shots as it can remove unwanted reflections from greenery & water etc. I understand that the CPL will decrease the exposure of the camera by around 2-stops. While the 0.6 ND grad is also a 2-stop equivalent.

Does people combine these 2 filters to use together? I wonder if that would create a too drastic outcome (underexpose)?

Any advice from those who had used a NDG &/or CPL? Thanks in advance :)
 

Sep 27, 2010
58
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0
#2
I think the CPL wld b more useful. It can make skies more blue and bring out the green in vegetation. N if you have a lens which the front element rotates rmb to reset ur polariser's angle again before you shoot.
 

Octarine

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Jan 3, 2008
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Pasir Ris
#3
Please read up about the purpose and function of both filters. While a CPL can serve as 2 stops ND the polarizing effect depends on other factors as well. Secondly, 2 stops is not that much, especially during day time. You can still achieve this with adjusting aperture or shutter. You may want to check for higher level (up to 9 or 10 stops, B+W, Hoya) in order to get certain effects. For landscape, GND is also used to reduce the Dynamic Range of the scene (vulgo: the brightness of the sky vs. the darker foreground in the scene).
Camera Lens Filters
; Dynamic Range
Any half-automatic mode of your camera will offset the light reduction by adjusting the shutter speed and / or ISO (check your manual for the respective details). That's why such shoots require a tripod usually.
For examples of using ND filters you may browse the Landscape gallery section. Check for night86mare's images.
Basically, filters can be combined. But there are side effects that can show up: colour cast, flare. The reason is simple: filters have plain surfaces. Multiple plain surfaces will cause multiple reflections.
 

daredevil123

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Oct 25, 2005
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lil red dot
#4
CPL is not a definite 2 stop. Some CPLs are 1 stops, some 1. 5 stops, some 0.75 stop. There are also situations where a CPL will not be suitable, ie, during sunset and sunrise, and it is causes a lot of problems on lenses that are very wide (like UWA).

GND and CPL does different things all together. Please read more to find out which one does what and you will know what you need. Don't buy filters for the sake of buying. Know what they are used for.

Personally, I find a 2-stop GND only useful for limited occasions on its own. It is still essential though, but need to be matched with a 3-stop GND (0.9). And you decide which to use at time of shooting to see which best suits the effect you looking for.
 

Sep 12, 2009
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#5
Just want to point out, Hitech is not cheap. If you don't know what you're doing, which is what it seems like, you might want to consider a cheaper option, or consider learning how to exposure blend first, rather than waste good money on something you might not be able to use properly.
 

daredevil123

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Oct 25, 2005
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lil red dot
#6
Just want to point out, Hitech is not cheap. If you don't know what you're doing, which is what it seems like, you might want to consider a cheaper option, or consider learning how to exposure blend first, rather than waste good money on something you might not be able to use properly.
Yup... and Hitech comes in 2 flavors as well, 85mm and 100mm. It is not just the filter only, but you need a filter holder as well. Unless you intend to handhold, which I strongly recommend against if you are going to do any sort of LE.

Know what you need before you buy. That means, know how it works before you buy.

Good luck! ;)
 

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#7
C-PL, ND and GNDs are used for different purposes. Be reminded that stacking filters can cause issues such as reflections caused by poor quality filters as well as vignetting on some wide angle lenses. C-PL are used to reduce reflections and also enhance the contrast of the sky. ND filters are used to reduce the amount of light entering the lens thus allowing photographer to make a longer exposure. A GND filter is similar to the ND filter but reduces the light gradually from bottom to the top. The GND filter is used in situation where you only want to limit light from part of the image which is too bright such as a landscape scene with a bright sky.
 

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#8
I'm just looking at the title of this topic. The comparison is on ND Grad (NDG) Vs Circular Polariser (CPL). As far as limited knowledge, NDG is those filters that gradually gets from lighter to darker, right? If yes, then CPL 100% cannot substitute a NDG.

I believe what we should be talking about ND filters. I've noticed photographer getting a whole array of ND filters (ND2, ND4, ND8, ND110 etc) as diffrent lighting situation may need different stops. So far no one is talking about it but, wouldn't a fader ND be better? So far from previous post in this forum, there are some users experienced vignetting with the fader ND @ UWA. I'm guessing a simple solution is to get a step up ring so that a bigger size fader ND can be used. Might be a little more expensive but should still be cheaper to get a few different ND filter, yes?
 

daredevil123

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Oct 25, 2005
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lil red dot
#9
I'm just looking at the title of this topic. The comparison is on ND Grad (NDG) Vs Circular Polariser (CPL). As far as limited knowledge, NDG is those filters that gradually gets from lighter to darker, right? If yes, then CPL 100% cannot substitute a NDG.

I believe what we should be talking about ND filters. I've noticed photographer getting a whole array of ND filters (ND2, ND4, ND8, ND110 etc) as diffrent lighting situation may need different stops. So far no one is talking about it but, wouldn't a fader ND be better? So far from previous post in this forum, there are some users experienced vignetting with the fader ND @ UWA. I'm guessing a simple solution is to get a step up ring so that a bigger size fader ND can be used. Might be a little more expensive but should still be cheaper to get a few different ND filter, yes?
Some people swear by variable ND filters. You can make your own variable ND too, by using two pieces of CPL filter, or a linear polarizer with a CPL stacked together.

Personally, I do not think they are very good. It can never replace a real 10 stop ND filter because by 6-8 stops, you will get this cross banding issue that gives you sort of like a 4 point star in the frame.

Also, sometimes when using variable ND filters, you can easily lose track of exactly how many stops it is set in now (the scale is not very accurate on some of these filters), making it very difficult to get the correct shutter speed at times.

That said, feel free to try them. They do not work for me, but they just might work for you. ;)
 

night86mare

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Aug 25, 2006
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#10
I am keen to purchase a Hi-Tec 0.6 ND grad (soft) , with an interest to shoot landscape/water shots etc. However, I also read from various sources that a Circular Polarizer (CPL) is recommended for landscape shots as it can remove unwanted reflections from greenery & water etc. I understand that the CPL will decrease the exposure of the camera by around 2-stops. While the 0.6 ND grad is also a 2-stop equivalent.

Does people combine these 2 filters to use together? I wonder if that would create a too drastic outcome (underexpose)?

Any advice from those who had used a NDG &/or CPL? Thanks in advance :)
hi,

why are you worried about underexposure? you can always keep iso + aperture constant, and then extend shutter speed to compensate.

when it goes beyond 30 seconds, still got bulb mode + remote.

have stacked before in the past, no issue. nowadays, i work a lot with ultra wide angles, so because of uneven polarisation, i no longer carry CPL around.
 

night86mare

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Aug 25, 2006
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#11
I believe what we should be talking about ND filters. I've noticed photographer getting a whole array of ND filters (ND2, ND4, ND8, ND110 etc) as diffrent lighting situation may need different stops. So far no one is talking about it but, wouldn't a fader ND be better? So far from previous post in this forum, there are some users experienced vignetting with the fader ND @ UWA. I'm guessing a simple solution is to get a step up ring so that a bigger size fader ND can be used. Might be a little more expensive but should still be cheaper to get a few different ND filter, yes?
can't use full range for UWA... if you check out the lightcraft website, they are very open about this point. i think if i'm not wrong, for UWA, can use max 2 stops.... not very useful at all...
 

giantcanopy

Senior Member
Feb 11, 2007
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SG
#12
Personally, I do not think they are very good. It can never replace a real 10 stop ND filter because by 6-8 stops, you will get this cross banding issue that gives you sort of like a 4 point star in the frame.

Also, sometimes when using variable ND filters, you can easily lose track of exactly how many stops it is set in now (the scale is not very accurate on some of these filters), making it very difficult to get the correct shutter speed at times
Maybe depends on maker ? The one I have specifies in their manual that it works well strictly up to 8 stops only.

ryan
 

Cam0909

New Member
Jan 21, 2010
22
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0
Singapore
#13
Please read up about the purpose and function of both filters. While a CPL can serve as 2 stops ND the polarizing effect depends on other factors as well. Secondly, 2 stops is not that much, especially during day time. You can still achieve this with adjusting aperture or shutter. You may want to check for higher level (up to 9 or 10 stops, B+W, Hoya) in order to get certain effects. For landscape, GND is also used to reduce the Dynamic Range of the scene (vulgo: the brightness of the sky vs. the darker foreground in the scene).
Camera Lens Filters
; Dynamic Range
Any half-automatic mode of your camera will offset the light reduction by adjusting the shutter speed and / or ISO (check your manual for the respective details). That's why such shoots require a tripod usually.
For examples of using ND filters you may browse the Landscape gallery section. Check for night86mare's images.
Basically, filters can be combined. But there are side effects that can show up: colour cast, flare. The reason is simple: filters have plain surfaces. Multiple plain surfaces will cause multiple reflections.
Thanks for the advice & attached links.
 

Cam0909

New Member
Jan 21, 2010
22
0
0
Singapore
#14
CPL is not a definite 2 stop. Some CPLs are 1 stops, some 1. 5 stops, some 0.75 stop. There are also situations where a CPL will not be suitable, ie, during sunset and sunrise, and it is causes a lot of problems on lenses that are very wide (like UWA).

GND and CPL does different things all together. Please read more to find out which one does what and you will know what you need. Don't buy filters for the sake of buying. Know what they are used for.

Personally, I find a 2-stop GND only useful for limited occasions on its own. It is still essential though, but need to be matched with a 3-stop GND (0.9). And you decide which to use at time of shooting to see which best suits the effect you looking for.
Thanks for your advice. Thou i had previously did some research on both GND & CPL, but i did not realise that CPL is not suitable for sunset/sunrise shots. I'm using a normal kit lens 18 - 55mm thou. I'll be doing some sunset shots, so i guess the GND will serve my needs better. Definately, I won't wish to buy filters that I rarely get to use... I guess I will juz buy a 2-stop GND to try out first, totally no experience in tis aspect. :bsmilie:
 

daredevil123

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Oct 25, 2005
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lil red dot
#15
Thanks for your advice. Thou i had previously did some research on both GND & CPL, but i did not realise that CPL is not suitable for sunset/sunrise shots. I'm using a normal kit lens 18 - 55mm thou. I'll be doing some sunset shots, so i guess the GND will serve my needs better. Definately, I won't wish to buy filters that I rarely get to use... I guess I will juz buy a 2-stop GND to try out first, totally no experience in tis aspect. :bsmilie:
If I can only buy one GND, I will get the 3-stop instead. But that is me.
 

daredevil123

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Oct 25, 2005
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lil red dot
#17
May i ask is get a 3-stop is it becos 2-stop difference is easily achieve in-camera (adjust the exposure compensation)?
I would go for a 3-stop mostly, because in PP I can recover details from a 2 stop exposure difference with good results (one stop overexposure for highlights, and one stop underexposure in low lights). But with a 2.5 to 3 stop difference, I will lose too much details.
 

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Cam0909

New Member
Jan 21, 2010
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Singapore
#18
I would go for a 3-stop mostly, because in PP I can recover details from a 2 stop exposure difference with good results (one stop overexposure for highlights, and one stop underexposure in low lights). But with a 2.5 to 3 stop difference, I will lose too much details.
Thanks for the explanation ;)
 

#19
can't use full range for UWA... if you check out the lightcraft website, they are very open about this point. i think if i'm not wrong, for UWA, can use max 2 stops.... not very useful at all...
Hi n86n,
Was going thru the lightcraft website, couldn't see anything about vari-nd not suitable for UWA. Could you point me to where it says that? I only can find the part it mentioned suitable for for UWA 2-8 stops. I'm kinda curious to know why it's not suitable. The only issue I can think of the vignetting issue and also the cross banding at certain position which dd123 had mentioned.
 

daredevil123

Moderator
Staff member
Oct 25, 2005
21,657
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lil red dot
#20
Hi n86n,
Was going thru the lightcraft website, couldn't see anything about vari-nd not suitable for UWA. Could you point me to where it says that? I only can find the part it mentioned suitable for for UWA 2-8 stops. I'm kinda curious to know why it's not suitable. The only issue I can think of the vignetting issue and also the cross banding at certain position which dd123 had mentioned.
And you can never be sure exactly how many stops when set at a certin darkness. Which will make shutter speed calculation extreme inaccurate. And if you are doing 5min long exposures, a single mistake will mean you miss the opportunity already.
 

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