Correct Aperture

canon400dcanon400d Banned UserPosts: 2,826Banned Major grins
edited May 3, 2012 in Technique
I would appreciate it so much if anyone can tell me what the correct guide lines are on apertures to use when operating a B & W 10 stop filter at daytime and sun set, night time. I am using a 5Dll on a 21-105. I am sure I read it somewhere that F22 has to be used when doing a long exposure. I have a table for the shutter speed and duration times with the filter on which I find extremely helpful.
Many thanks
Bob

Comments

  • OffTopicOffTopic Searching for the light Posts: 499Registered Users Major grins
    edited May 1, 2012
    Actually the only time you should use f/22 or smaller (higher) is when you absolutely need to in order to reduce the amount of light to permit a longer exposure time to get the effect you want (such as cloud movement requiring 5-6 minute exposure). At f/22 you'll have to deal with diffraction and every single spot of dust on your sensor showing in the frame. An alternative in that situation is to stay around f/16 (assuming landscape or similar and you want the DoF) and stack another ND filter on. If you only have one ND stack your polarizing filter on top of your ND.
  • SamSam San Jose CA Posts: 7,418Registered Users Major grins
    edited May 1, 2012
    To add to this, there is no "correct" aperture. The aperture is chosen for a variety of reasons, DOF, effect, to adjust shutter speed, subject, etc.

    One example: Bright sunlight yet you want to shoot at f1.4. That's going to be tough, you may not be able to get a high enough shutter speed on your particular camera to achieve a proper exposure, but if you add a neutral density filter you will be able to shoot at wide open and get shutter speeds with in your cameras capabilities.

    Another pretty standard reason to use a ND filter is to slow the shutter speed down to get motion blur like silky water.

    As stated above normally you don't want to use f22 because of diffraction. For land scape I would recommend f11 to f16, no higher.

    Marc Munch (I believe) recommends f11

    Sam
  • canon400dcanon400d Banned User Posts: 2,826Banned Major grins
    edited May 2, 2012
    Sam wrote: »
    To add to this, there is no "correct" aperture. The aperture is chosen for a variety of reasons, DOF, effect, to adjust shutter speed, subject, etc.

    One example: Bright sunlight yet you want to shoot at f1.4. That's going to be tough, you may not be able to get a high enough shutter speed on your particular camera to achieve a proper exposure, but if you add a neutral density filter you will be able to shoot at wide open and get shutter speeds with in your cameras capabilities.

    Another pretty standard reason to use a ND filter is to slow the shutter speed down to get motion blur like silky water.

    As stated above normally you don't want to use f22 because of diffraction. For land scape I would recommend f11 to f16, no higher.

    Marc Munch (I believe) recommends f11

    Sam

    Thanks ever so much for those replies very useful indeed. It is quite easy to add another filter using the Cokin filters but how would I go about fitting another filter to a B & W 10 stop filter. Secondly what is the point because the B & W blacks everything out. Now we are on this subject what about ISO has it always to be set at 100?
    Many thanks
    Bob
  • SamSam San Jose CA Posts: 7,418Registered Users Major grins
    edited May 2, 2012
    Bob,

    Lets make this easy on me. :D

    Tell me what your are trying to do with as much detail as possible.

    Sam
  • canon400dcanon400d Banned User Posts: 2,826Banned Major grins
    edited May 2, 2012
    Sam wrote: »
    Bob,

    Lets make this easy on me. :D

    Tell me what your are trying to do with as much detail as possible.

    Sam

    Hi Sam,
    I have just bought a B&W 10 stop filter using 7d and 24-105. I have listened and viewed several tutorials and they are all somewhat different. The method I use is I compose the shot in AV and then turn off AF and change to manual mode making sure the settings are the same as AV. I then carefully screw on the filter and change to Bulb mode once again checking the aperture is the same as AV and Manual. I use the cable to take the shot. I have a table of times, with and without the filter, which I find very useful indeed.
    My problem is knowing how long to expose the image in daylight or dusk. I was using F22 but will change that in future to F11 - F16. All the tutorials say ISO 100. Is this correct? For instance if I wanted a shutter speed of 1 second with the filter would take 17mins 4secs according to my table. I cannot get that 1 sec in AV, so I suppose I would use Manual, but would I ever need to use that 1 sec setting for normal landscape photos.
    I have always used Cokin filters and have the polariser and grad 2, 4 and 8 stop and the ND 153 and 154 for slowing down the shutter speed. My B&W is a screw on, so how do you add another filter. I would have thought that this filter would be quite sufficient as it cuts out all the light.
    I hope I have made myself reasonably clear Sam for you to follow.
    Many thanks
    Bob
  • OffTopicOffTopic Searching for the light Posts: 499Registered Users Major grins
    edited May 2, 2012
    Stacking screw-on filters requires having multiple screw-on filters. If you look at the front of your B+W filter you'll see threads that will allow you to screw another filter on top of it. I'm not sure if your Cokin holder would screw on to your B+W filter, if it does vignetting might be a concern.

    The tutorials tell you to use ISO 100 because the reason one uses an ND filter is to reduce the amount of light reaching the sensor to allow a longer exposure for creative purposes. Increasing the ISO would require a faster shutter speed to get the same exposure, defeating the purpose of using the ND filter. You usually want to get as slow a shutter speed as possible. Long exposures also increase noise which is a greater concern at higher ISOs.

    Your 10-stop ND filter may look black, but it does not block 100% of the light. Depending on how bright the sunlight is and what your creative intent is, there are times when a 10-stop filter may not be enough. Joel Tjintjelaar, a master of black and white LE photography, routinely stacks up to 20-stops to get the effects seen in his landscape photos.

    "would I ever need to use that 1 sec setting for normal landscape photos?"

    Depends on your creative intent but if your camera calculates a 1 second exposure without the filter, you are shooting in low light and probably don't need the 10 stop filter. Since you have the Cokin ND153 and ND 154 you can use one of them instead (or stack them to get 5 stops). You have to think backwards...how long of an exposure do you need to get the creative effect you want, and then figure out which ND will get you there. You are lucky in that you have a good choice of ND filters in your bag.
  • SamSam San Jose CA Posts: 7,418Registered Users Major grins
    edited May 2, 2012
    canon400d wrote: »
    Hi Sam,
    I have just bought a B&W 10 stop filter using 7d and 24-105. I have listened and viewed several tutorials and they are all somewhat different. The method I use is I compose the shot in AV and then turn off AF and change to manual mode making sure the settings are the same as AV. I then carefully screw on the filter and change to Bulb mode once again checking the aperture is the same as AV and Manual. I use the cable to take the shot. I have a table of times, with and without the filter, which I find very useful indeed.
    My problem is knowing how long to expose the image in daylight or dusk. I was using F22 but will change that in future to F11 - F16. All the tutorials say ISO 100. Is this correct? For instance if I wanted a shutter speed of 1 second with the filter would take 17mins 4secs according to my table. I cannot get that 1 sec in AV, so I suppose I would use Manual, but would I ever need to use that 1 sec setting for normal landscape photos.
    I have always used Cokin filters and have the polariser and grad 2, 4 and 8 stop and the ND 153 and 154 for slowing down the shutter speed. My B&W is a screw on, so how do you add another filter. I would have thought that this filter would be quite sufficient as it cuts out all the light.
    I hope I have made myself reasonably clear Sam for you to follow.
    Many thanks
    Bob

    Bob, rolleyes1.gifroflrolleyes1.gifrofl

    That's me laughing my fat little butt off.

    Let me try and rephrase my question. I am trying to understand what you want to achieve, not exactly what your doing now.

    I can say this as a quick test I used my B&W 6 stop screw in filter and held a Lee 3 stop filter in front of that with my 5D II. I was able to get quick AF lock even in areas that looked completely black through the view finder.

    So I am at a loss as to why you would need to get AF, switch to manual focus and attach all the filters and calculate the exposure times.

    It is unclear to me what you are attempting to accomplish. Can you specify the end result you are looking for?

    As an example one could pose the question: I want to create an image of a waterfall and want the water to have that smooth silky look I see. When I try taking a photo of a waterfall in daylight using ISO 100 and an aperture of f16 the shutter speed is too fast and the water is crisp and detailed. What do I do?

    Sam
  • canon400dcanon400d Banned User Posts: 2,826Banned Major grins
    edited May 2, 2012
    Sam wrote: »
    Bob, rolleyes1.gifroflrolleyes1.gifrofl

    That's me laughing my fat little butt off.

    Let me try and rephrase my question. I am trying to understand what you want to achieve, not exactly what your doing now.

    I can say this as a quick test I used my B&W 6 stop screw in filter and held a Lee 3 stop filter in front of that with my 5D II. I was able to get quick AF lock even in areas that looked completely black through the view finder.

    So I am at a loss as to why you would need to get AF, switch to manual focus and attach all the filters and calculate the exposure times.

    It is unclear to me what you are attempting to accomplish. Can you specify the end result you are looking for?

    As an example one could pose the question: I want to create an image of a waterfall and want the water to have that smooth silky look I see. When I try taking a photo of a waterfall in daylight using ISO 100 and an aperture of f16 the shutter speed is too fast and the water is crisp and detailed. What do I do?

    Sam

    Thanks ever so much Lori and you too Sam for your detailed replies which I truly appreciate. I am sure what each of you have told me you have put me on the correct lines for using this filter. The reason Sam I started with AV and then Manual and so on and so on is because I was following a couple of tutorials I had viewed. I have seen some beautiful images of sunrise and sunset together with waterfall shots and this is what I am trying to achieve. I was doing quite well with the waterfall shots using 154 but when I purchased the B&W 10 stop I have been somewhat confused.
    I suppose once I have taken a few shots I hope things will drop into place.
    By the way Sam is there a better procedure than the one I am using. Thanks once again for all your kind help.
    Cheers
    Bob
  • SamSam San Jose CA Posts: 7,418Registered Users Major grins
    edited May 3, 2012
    Bob,

    Rather than using a cook book approach I think it would be better to get a good understanding of the three main camera functions and how they interrelate to achieve correct or desired exposure.

    The ISO setting controls the sensitivity of of the camera sensor. The higher the ISO setting the more sensitive to light the sensor will be. This will increase the shutter speed to obtain correct exposure. Note: there are some side effect of using higher ISO settings such as increased noise and increases color saturation.

    A larger aperture (smaller number) will let in more light and increase shutter speeds. A smaller aperture will decrease the amount of light and decrease the shutter speed. Note: a large aperture (small number) will have a small DOF and a smaller aperture (large number) will have a larger DOF.

    A slow shutter speed will allow more light in and a faster shutter speed will allow less light in. Note: A slow shutter speed can result in a blurry image (camera shake) or an image where subjects are moving to blur. A fast shutter speed will tend to provide a crist image with motion frozen.

    Now the object of all this is o think through what your trying to accomplish and / or achieve with your image and balance out these three factors to get that look while minimizing the downside of any particular setting.

    It's all a balancing act. Now when as an example your trying to get water to have that silky smooth look and the ambient light is too bright to achieve a slow enough shutter to achieve this silky look and have a correct exposure we need to add a ND filter to slow the shutter down even more without increasing the exposure.

    I wouldn't worry too much about any specific shutter speeds for this except to know we need to get into at least several seconds to achieve the look.

    My thought process would be to set the camera at ISO 100 f16 in AV mode. Have a quick look at what the camera determines the correct shutter speed to be. I am basically using the cameras built in systems as a light meter. At this point I can see if the shutter speed is slow enough to blur the water. If not I would need to add a ND filter. I would put my 6 stop filter on and repeat the process. Now if the shutter is too slow I can always increase the ISO and / or open up the aperture.

    When it comes to sunsets I think you need to look at a split ND filter and treat the sun sky as one exposure issue and the foreground as a second independent exposure issue.

    The key: Understand what each adjustment option at your disposal does and experiment. Play see what results from the various settings. Have fun!

    I hope this is clear.

    Sam
  • canon400dcanon400d Banned User Posts: 2,826Banned Major grins
    edited May 3, 2012
    Sam wrote: »
    Bob,

    Rather than using a cook book approach I think it would be better to get a good understanding of the three main camera functions and how they interrelate to achieve correct or desired exposure.

    The ISO setting controls the sensitivity of of the camera sensor. The higher the ISO setting the more sensitive to light the sensor will be. This will increase the shutter speed to obtain correct exposure. Note: there are some side effect of using higher ISO settings such as increased noise and increases color saturation.

    A larger aperture (smaller number) will let in more light and increase shutter speeds. A smaller aperture will decrease the amount of light and decrease the shutter speed. Note: a large aperture (small number) will have a small DOF and a smaller aperture (large number) will have a larger DOF.

    A slow shutter speed will allow more light in and a faster shutter speed will allow less light in. Note: A slow shutter speed can result in a blurry image (camera shake) or an image where subjects are moving to blur. A fast shutter speed will tend to provide a crist image with motion frozen.

    Now the object of all this is o think through what your trying to accomplish and / or achieve with your image and balance out these three factors to get that look while minimizing the downside of any particular setting.

    It's all a balancing act. Now when as an example your trying to get water to have that silky smooth look and the ambient light is too bright to achieve a slow enough shutter to achieve this silky look and have a correct exposure we need to add a ND filter to slow the shutter down even more without increasing the exposure.

    I wouldn't worry too much about any specific shutter speeds for this except to know we need to get into at least several seconds to achieve the look.

    My thought process would be to set the camera at ISO 100 f16 in AV mode. Have a quick look at what the camera determines the correct shutter speed to be. I am basically using the cameras built in systems as a light meter. At this point I can see if the shutter speed is slow enough to blur the water. If not I would need to add a ND filter. I would put my 6 stop filter on and repeat the process. Now if the shutter is too slow I can always increase the ISO and / or open up the aperture.

    When it comes to sunsets I think you need to look at a split ND filter and treat the sun sky as one exposure issue and the foreground as a second independent exposure issue.

    The key: Understand what each adjustment option at your disposal does and experiment. Play see what results from the various settings. Have fun!

    I hope this is clear.

    Sam
    That is absolutely first class Sam. I can fully understand what you have said and I really appreciate you taking your time to outline everything so clearly for me. I am much happier now than I was when I first received this filter.
    Cheers
    Bob
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