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Thread: Flash or macro?

  1. #11
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    Re: Flash or macro?



    EdN,


    That's a very interesting shot. I see you were at f/14, yet the bokeh is very diffuse. How far were you from the subject, and how far was the background behind it?

  2. #12
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    Re: Flash or macro?



    The closest focus distance of the 100 F2.8 is about a foot and I think that I was pretty close to that limit. The background was also about a foot or foot and a half away. The closer you shoot with a lens compresses the depth of field. So at one foot, even at F14, there is only a relative shallow depth of field at that distance. All I got in focus was the top of the buds and no more. I had to jack up the ISO to use F14.


    I was out looking for frost on leaves and the snow flakes caught my eye. I'll try to find some 100 macro flower shots using the 580EX. (That was two seasons ago!)

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  4. #14
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    Re: Flash or macro?



    HiFiGuy1-


    I think your picture is fine. Many people like the narrow depth of field effect.


    However, if you want to get the whole thing in focus, shooting from further away with a longer lens won't help. All that matters is f/ number (and how you frame the picture). So the only thing you can do to get more dof is to stop down. It gets worse as magnification increases. Look how tiny the depth of field is on this grasshopper picture:





    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.93/grasshopper.JPG[/img]





    It was also taken at f/5.6, and I used a 100mm macro lens (with extension tubes). If you looked at a 1-1 crop of this picture, you would see that not even the entire *eye* of the grasshopper is in sharp focus.


    This is one of the tricky aspects of close-up photography: the more you magnify, the smaller your depth of field. So for closeups you have to stop way down to get your subject in focus (notice the narrow dof in EdN's picture, even though it is at f/14) . When you stop down, though, it is tough to get enough light. And you stop way down, diffraction becomes an issue. Worse, both the light and diffraction issues get worse at a given f/number as magnification increases... TTL metering be blessed!


    If it was easy, it wouldn't be so much fun.


    I guess









  5. #15
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    Re: Flash or macro?



    Dann,


    I REALLY like the second shot. The petals seem to melt smoothlyinto the background from being in sharp focus up front. What were your settings and positioning with this shot?

  6. #16
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    Re: Flash or macro?



    Quote Originally Posted by Jon Ruyle


    HiFiGuy1-


    I think your picture is fine. Many people like the narrow depth of field effect.


    However, if you want to get the whole thing in focus, shooting from further away with a longer lens won't help. All that matters is f/ number (and how you frame the picture). So the only thing you can do to get more dof is to stop down. It gets worse as magnification increases. Look how tiny the depth of field is on this grasshopper picture:





    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.93/grasshopper.JPG[/img]





    It was also taken at f/5.6, and I used a 100mm macro lens (with extension tubes). If you looked at a 1-1 crop of this picture, you would see that not even the entire *eye* of the grasshopper is in sharp focus.


    This is one of the tricky aspects of close-up photography: the more you magnify, the smaller your depth of field. So for closeups you have to stop way down to get your subject in focus (notice the narrow dof in EdN's picture, even though it is at f/14) . When you stop down, though, it is tough to get enough light. And you stop way down, diffraction becomes an issue. Worse, both the light and diffraction issues get worse at a given f/number as magnification increases... TTL metering be blessed!


    If it was easy, it wouldn't be so much fun.


    I guess






    Jon,


    Okay. I understand the DOF issue as it relates to f number, I think. I also get the depth compression with longer focal length and closer subject proximity. What I guess I don't understand is, in my flower shot, I have parts of the flower cluster already starting to be out of focus, yet the leaves and mulch, which I'd like to be a featureless blur of background color, are all too distinguishable. With my limited knowledge (I promise I'm trying to learn!), I would have thought that increasing the f number to f/8 or f/11 would have reduced the background bokeh, given the same subject distance and focal length, though it would have fixed the focus on the cluster itself. How do I achieve both goals without a longer focal length? For instance, if I had been using a 200mm, and say f/8 or f/11 to get the whole cluster in focus, with the same composition (and therefore further from the subject), wouldn't I have achieved my goal? Or would the increased distance necessary for the equal composition negate my depth compression and give me anequal bokeh diffusionto the current shot?



    Does a macro's 1:1 magnification allow closer shots with a greatly increased distance compression? Is thata different way of saying what you did about the DOF being less with higher magnification? In other words, cana 100mm macro lens, opened up to 11 or 14, give both greater diffusion in the background and allow the subject to be in focus, if that is what I want to achieve? If not, it seems like I might be better off saving up for the 70-200 f/2.8 L IS that I ultimately feel destined to own. [] Then I could use it at or near 200mm, with f/5.6 or 8, and just get as close as possible for the compositions. Then I'd have depth compression with great diffusebackground blur behind the subject, but sharp, crisp images of the subject itself. Or are these just two different ways to achieve the same end result? Is that possible?


    Also, am I being hampered by the fact that my camera isAPS-C? Is a FF sensor going to give me better results, or at least what I'm describing here as my desire for this shot?

  7. #17
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    Re: Flash or macro?



    I woudl go with the 100mm f/2.8 macro first. [8-|]



  8. #18
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    Re: Flash or macro?



    So I totally misunderstood your question.


    Sounds like you understand the situation at least as well as I do It is true that most people feel that backgrounds are more blurry if the focal length is longer. In your case, a longer lens might have helped some. However, my guess is that the best solution is to change the angle to get a background you like better. Tiny blades of grass turn into a sea of green more easily than big leaves.


    It is also true that the macro will allow more blur at a given f number if you get closer, but of course, this doesn't help you here. On the other hand, if you take true macros (1x magnification and beyond) you'll probably seldom have to worry about blurring the background. You'll have the opposite problem (as I did with the grasshopper).


    FF won't help you. You get less more bakground blur with a given framing, true, but only because you have less dof. The only difference with a larger sensor is that the lens will seem shorter (which is the opposite of what you want... if anything, moving away and cropping might have helped).


    BTW, I also own the 70-200 IS, and use it for medium close-ups, but I don't think I've ever used it for the reason you're describing. And I use the macro for closeups far more.

  9. #19

    Re: Flash or macro?



    Here's a Canon XTi, 100mm f2.8 Macro. f8, 1/400, ISO 1600, on a cloudy day


    Who needs a flash?


    [img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.24.20/IMG_5F00_5899.JPG[/img]

  10. #20
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    Re: Flash or macro?



    looks tastey

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