a CPL or ND grad?

Discussion in 'Accessories' started by mesmerized, Jul 16, 2013.

  1. mesmerized

    mesmerized Mu-43 Veteran

    344
    Jun 18, 2012
    Howdy,

    I've been doing some research on types of filters and although I've been recommended getting a CPL, this made me question my initial choice:

    A polarising filter is just like polarised sunglasses in that they cut glare. Polarisers are not normally used for wide-angle shots that include sky, as you'll get a very uneven sky tone due to the wide range of angles of the light entering the lens.

    Should I get an ND grad (or actually a split ND filter) instead of a CPL?

    Thanks a million
     
  2. lawa222

    lawa222 Mu-43 Rookie

    16
    Mar 3, 2013
    Unless you're shooting very wide -- think fisheye-wide -- it's not much of a problem. Generally it comes close to matching natural shifts in the color of the sky.

    Maybe try buying a cheap one (they can be had for $10ish), then upgrade to a nice one if you like the effect, which I suspect you will. Most good landscape photographers consider the polarizer an absolute essential. ND grads are less essential in the digital age because they can be more easily faked in post-process.

    The other thing people forget about CPL's is that they don't just make the sky blue, they also preserve a TON of extra color and detail on surfaces that tend to get shiny or glossy, particularly foliage and water.

    Finally, it's not really an either/or because they do different things. ND grads are so you don't overexpose skies that are FAR brighter than the dynamic range of your camera can handle while metering appropriately for the landscape. They're particularly useful at sunrise, sunset, and in strange lighting like heavy clouds that some bright light is getting through. Polarizing filters make the entire scene a stop or two darker (your camera will compensate) while cutting glare and reflections, which makes the sky bluer, clouds more pronounced, and other effects. They can be useful in basically every outdoor condition, although sometimes less useful than a ND grad.
     
  3. mesmerized

    mesmerized Mu-43 Veteran

    344
    Jun 18, 2012
    Thanks lawa222 for a nice explanation. There's one thing that makes me wonder... It seems that there are no circular gradual ND filters available. Looks like they only come in the shape of a square/rectangle and a special holder nas to be mounted on the camera. Is that so?

    One more thing. What is a CPL(W) filter? I guess it stands for wide band but I'm not sure what's the difference between a wide and non-wide band filter.
     
  4. Petrochemist

    Petrochemist Mu-43 Top Veteran

    655
    Mar 21, 2013
    N Essex, UK
    Mike
    I suspect the lack of circular graduated filters is because the circular format does not allow you to adjust the height of the graduation. I find grads difficult enough to fit well to the sky/land interface - theres frequently trees/hills... making the transittion far from straight.
    As Iawa222 points out the CPL is far more useful controlling reflections either increasing or reducing them as desired.
     
  5. lawa222

    lawa222 Mu-43 Rookie

    16
    Mar 3, 2013
    They are square so you can move them up and down in the holder to align with your horizon. A circular one would limit your framing options b/c you'd have to put the horizon at the same line all the time. Honestly, I wouldn't bother to carry an ND grad unless you like to scout locations, wait for the right weather, set up your tripod, wait for perfect light, and take your perfect shot Ansel Adams-style (exaggerating a bit).

    I think wide band is just a term certain companies use for some technology they claim makes their filters better. Below $50 they're all mostly the same. Above $50 they're all mostly the same. I use the Hoya HD because I find them easiest to clean. B&W generally has highest build quality.
     
  6. mesmerized

    mesmerized Mu-43 Veteran

    344
    Jun 18, 2012
    have you ever heard about a brand called Kase?
     
  7. Just Jim

    Just Jim Mu-43 Top Veteran

    941
    Oct 20, 2011
    You should have a polarizer. Extremely useful filter and in a lot of ways one of the more complicated to use correctly. Light Science and Magic has a great section on how they work and how they should be used. Buy the best one you can get. Cheaper ones, or at least cheaply made ones, can give you problems with ugly color shifts, and/or near 3 stops of light loss. Compared to a Singh Ray which you can pick your color shift, warming, neutral, or cool and only lose 1.5 stops of light or less. IMO, their filters are the absolute best. Even compared to Lee's, Hi-Tech, and B+W.

    ND's. A lot of people will say, you don't need them. Well I say they are wrong. One simple reason, You can't get detail out of a highlight or shadow that is blown at the time of exposure. HDR isn't really an effective solution for consistent results, because you can't always predict how the image will result. With ND's you will know when at the time of capture if you got the shot. Another less important but valid reason, is that you will keep the ratios of colors and luminance of an image balanced, compared to an editing program where it doesn't always stay balanced because we do no edit on a pixel to pixel basis. The more an image is worked the more it breaks down, and ND's save time. I love them. Again when looking at reviews, make not if there are repeated complaints abut color shifts, warm and cool shifts are workable in a budget ND, expensive ones should have little shift unless they specifically say it has one and you want it. Some cheaper made ones will have odd tertiary color shifts that are really annoying to correct for. If you do get a cheaper model I also suggest a color checker card. X rite makes one that comes with a piece of software that you can create separate profiles for, so once you know the filters shift, correct, create a profile save it, and one click correction in lightroom.
     
  8. LovinTheEP2

    LovinTheEP2 Mu-43 Top Veteran

    619
    Feb 15, 2011
    Toronto
    You can't get a circular nd cause rarely is the horizon dead center in your photo. The reason they're rectangular is so you can move up manually up and down to match you composition.

    There is another option that expensive and for you, basedly on all your posts and questions and not fully understanding role of filters could be a dual like Singh rays vario dual. Has a polarizer and nd built in together with an adjustment ring. You don't get grad but at least you can prevent overexposure when shooting wide open on the 45.

    These 2 filters ie polarizer and nd grad are completely different and its not a matter of which to get - its not a choice. Its what you want. Understand too that a polarizer only works in certain situations as well. Not every photo will benefit from it, all depends on the angle of light. And it typically slows your lens 1-3 stops depending on the quality of glass. The cheap ones that are 3 stop could result in longer shutter speeds then u might desire leading to motion blur etc.

    ND effect can be acheived in software yes but that's also a fallacy as once you overexpose and blow out detail you can rarely recover details and its a fake grad. The nd grad perserve those details.

    Using a filter COMPLICATES photography, could degrad IQ, shifts exposure etc. They should be used if you fully understand their role. Those 2 filters are really effective if you understand how to use em.

    Plus. Anytime you put a filter in front of a high quality glass like the 45, 75, 25, 20 etc you risk degrading image quality as the filter is probably lower quality then the lens your using. So the lens becomes only as good as the filter glass. B&W, Singh, Lees are considered higrade. Don't put a cheap filter on and expect to maintain the level of image quality the 45 is known for. Go naked and use a filter only when needed.
     
  9. mesmerized

    mesmerized Mu-43 Veteran

    344
    Jun 18, 2012
    Thanks guys.

    Well, I bought a Kenko PRO1D series CPL(W) filter. I hope it's good enough.
     
  10. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    A CPL is a great place to start. To me, it's the most useful filter because the effects it produces cannot be replicated after the time of capture.

    If you are shooting RAW, the file will generally have enough latitude that you can achieve a similar result after the fact to what you could achieve with a graduated ND filter (and applying such an effect is dead easy if you use Lightroom).

    Once you get the CPL, shoot with it for a while and see if you find it useful before determining if you feel that an ND or grad ND is going to be worthwhile for the type of shooting you are doing.
     
  11. danska

    danska Mu-43 Top Veteran

    945
    May 21, 2012
    Portland, OR
    Joe
    This is spot on.

    A CPL is the best filter to have in your bag. I have one in both 46/58mm so it works on most of my lenses. I prefer the Hoya HD because of the greater light transmission over the B+W (for no other real reason). The only issue where you start to see the reflection that causes uneven skies etc, is when you get wider than 20mm or so? Can't quite remember but I see it more in the 12-14mm shots than I do above that.
     
  12. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    For posterity, you don't need a CPL (circular polarizer) for our cameras, a linear will be fine, and they are usually cheaper (and more effective)

    A CPL includes a "quarter plate" that corrects the potential phase shift from the polarizer that interferes with the operation of phase-detect autofocus (PDAF - what SLR cameras use)

    Back OT - I never shoot outside without a polarizer mounted due to the color improvement.
     
  13. peteygas

    peteygas Mu-43 Rookie

    22
    Nov 21, 2011
    sedona arizona
    Correct technically you don't. need CPL , but manufacturers stopped making good ones with the advent of Dslrs
     
  14. RT_Panther

    RT_Panther Mu-43 Legend

    May 4, 2011
    Texas
    Now I've got to dig in my close to see if I can find my one and only gradated ND filter....:redface:
     
  15. LovinTheEP2

    LovinTheEP2 Mu-43 Top Veteran

    619
    Feb 15, 2011
    Toronto
    Make sure you let us know how the cpl works out for you and if you figure out how to get the most out of the 45
     
  16. mesmerized

    mesmerized Mu-43 Veteran

    344
    Jun 18, 2012
    Hey there!

    I've been testing the CPL and one thing has made me wonder... I don't really see any difference when I'm moving the ring. Is it just me? Perhaps I'm blind.
     
  17. mesmerized

    mesmerized Mu-43 Veteran

    344
    Jun 18, 2012
    Any comments upon my last post :D ? Thanks!
     
  18. Cruzan80

    Cruzan80 Mu-43 All-Pro

    Aug 23, 2012
    Denver, Co
    Sean Rastsmith
    Are you using the LCD or EVF? Polarizers work best when the sun is at an angle. I would try turning it slowly in a highly contrasty area. Turning it 1\4 turn will take you through the full range. You can also use it to cut out reflections in glass or water.

    Sent from my LG-P769 using Mu-43 mobile app
     
  19. Neftun

    Neftun Mu-43 Veteran

    408
    Jul 15, 2012
    Norway
    Patrick Kristiansen
    Try taking a photo of your car in sunlight. You should see a dramatic difference when turning the ring. Also landscaping with water, or trough a window. Have anyone explained to you the physics behind polarizing light?
     
  20. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    The effect of a polarizer can be very difficult to see particularly on a live view screen, since the camera adjusts the brightness of the display as you rotate the filter. One thing you can do is mark the filter in quadrants on the outer edge (with a file or some fingernail polish) and take some test shots it different orientations. This should give you some idea of where in the rotation the effect is strongest although this will vary somewhat with the direction of the light. Another thing you can do is to watch the exposure parameters as you twist the filter, which will give you an idea if how much light the filter is blocking.

    sent with my phone...please excuse the typos