Macro Exercises #1 DOF, Aperture and diffraction

Lord VetinariLord Vetinari SmugbugPosts: 15,462Registered Users Major grins
edited October 19, 2013 in Holy Macro
Skippy and others have ganged up on me to do some Macrophotography learning exercises. The idea is for me to show some examples of technique and then for you to shoot something similar- learn from what you have shot and then post back the requested exercise example. I'm primarily aiming these at DSLR owners with a 1:1 macro lens capability.
Exercise 1
DOF and aperture. Set your camera to M mode and the lens to MF, 1/200th, ISO200, with either an external flash or the internal flash popped up. get a small object that has fine detail about 1/2" long (13mm )- I used a small flat headed screw for this. place it on a table with the pointy end facing you and then rotate it about 45' away from you. Set the lens at minimum focus (ie 1:1), and aperture at F2.8 and place the end of the lens on the table and then push the camera forward until you get sharp focus on the tip of the object. Take a pic and repeat for apertures F8,F13 and F20.

F2.8

140855083-M.jpg

F8

140855115-M.jpg

F13

140854753-M.jpg

F20

140854802-M.jpg

Your pics should look something like the above. Obviously the DOF increases as the aperture gets smaller. So why don't we shoot macro at F20 ?.
Apart from a requirement for flash or long exposures to do so, there is another downside, diffraction softening. If you blow your pics at F8 and F20 up on your PC screen and find an area where both are in sharp focus, you will find the detail in the F8 shot is a lot clearer than the detail in the F20 shot. This is diffraction softening at work.
This does not mean you should not use small apertures- many subjects often do not actually have much fine detail so you are not going to lose anything shooting at small apertures but for general shooting at 1:1, I tend not to go below about F11.
So how can we get as much of the subject in focus at larger apertures?.
One obvious answer is to shoot the subject sideways on such as below

(F8)

140854850-M.jpg

This is quite a common way of shooting say bugs but can be a bit boring from a composition point of view- this can be improved by shooting at a slight angle so the subject is sloping up or down in the picture.
A slightly better way of doing it is to use what I call magical angles. If you approach the subject head on and level with it, then move the camera sideways about 45' and up about 45' you get much more of the subject in focus and the angle makes for a more pleasing composition.
F8 again

140854933-M.jpg

Exercise
Firstly repeat the shoot yourself and convince yourself about diffraction softening and also using different angles on the subject. Then find a different subject to shoot about the same size and choose your aperture and angle to shoot it at and post back the result with your EXIF data and why you chose that aperture in this thread.
Not sure how long we will run each exercise but somewhere between 2-4 weeks I suspect
I'd also appreciate any comments on whether this type of exercise is useful and perhaps other potential topics (assuming I know anything about them).
Likely future topics.
1. Light and flash use.
2. Focus stacking
3.Shooting bugs.
4. macrophotography styles
5. Focusing techniques
Brian V.
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Comments

  • Awais YaqubAwais Yaqub One Inspired soul Posts: 10,565Registered Users Major grins
    edited April 3, 2007
    Great lesson

    so everything at F2.0 or less will be completely gone ?
    Thine is the beauty of light; mine is the song of fire. Thy beauty exalts the heart; my song inspires the soul. Allama Iqbal

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  • Lord VetinariLord Vetinari Smugbug Posts: 15,462Registered Users Major grins
    edited April 3, 2007
    Great lesson

    so everything at F2.0 or less will be completely gone ?
    Thanks Awais - you have a macro lens that does F2.0 ?
    No obviously the DOF is even thinner- many people use those expensive wide aperture lenses for purposely isolating the subject from the background in say portrature.
    Hope you are going to try the exercise mwink.gif
    Brian V.
  • Awais YaqubAwais Yaqub One Inspired soul Posts: 10,565Registered Users Major grins
    edited April 3, 2007
    Thanks Awais - you have a macro lens that does F2.0 ?
    No obviously the DOF is even thinner- many people use those expensive wide aperture lenses for purposely isolating the subject from the background in say portrature.
    Hope you are going to try the exercise mwink.gif
    Brian V.

    headscratch.gif No it just came into my mind ne_nau.gif
    what for PS users ?
    Any way thanks for reply :D
    Thine is the beauty of light; mine is the song of fire. Thy beauty exalts the heart; my song inspires the soul. Allama Iqbal

    Gallery
    fineartprints.shop
  • Lord VetinariLord Vetinari Smugbug Posts: 15,462Registered Users Major grins
    edited April 3, 2007
    headscratch.gif No it just came into my mind ne_nau.gif
    what for PS users ?
    Any way thanks for reply :D

    Many of the same ideas will apply to PS users but for example the aperture effects will be different because of the small sensor size. So a PS user would just need to try to divide their aperture range by 3 to give 4 apertures to try the same thing on.
    Brian V.
  • RogersDARogersDA Unknown...and happy. Posts: 3,502Registered Users Major grins
    edited April 3, 2007

    Exercise
    Firstly repeat the shoot yourself and convince yourself about diffraction softening and also using different angles on the subject. Then find a different subject to shoot about the same size and choose your aperture and angle to shoot it at and post back the result with your EXIF data and why you chose that aperture in this thread.
    Not sure how long we will run each exercise but somewhere between 2-4 weeks I suspect
    I'd also appreciate any comments on whether this type of exercise is useful and perhaps other potential topics (assuming I know anything about them).
    Likely future topics.
    1. Light and flash use.
    2. Focus stacking
    3.Shooting bugs.
    4. macrophotography styles
    Brian V.

    clap.gifthumbclap.gifthumbclap.gifthumb
    Thanks for this!!
  • DalantechDalantech No cropping zone... Posts: 1,519Registered Users Major grins
    edited April 3, 2007
    *Dal sends 20 Euro to Skippy's Pay Pal account*

    Cool post Brian! :D

    I'll see if I can do the exercise on one of the critters I shoot...
    My SmugMug Gallery

    Looking for tips on macro photography? Check out my Blog: No Cropping Zone.
  • Lord VetinariLord Vetinari Smugbug Posts: 15,462Registered Users Major grins
    edited April 3, 2007
    Dalantech wrote:
    *Dal sends 20 Euro to Skippy's Pay Pal account*

    Cool post Brian! :D

    I'll see if I can do the exercise on one of the critters I shoot...
    Thanks John,
    Worth trying the diffraction/aperture test on a bugs compound eye if you can find one that will sit still for long enough :)
    Brian V.
  • SkippySkippy Forensic Wannabe Posts: 12,075Registered Users Major grins
    edited April 3, 2007

    Hooray for Brian clap.gif :ivar clap.gif nothing like learning from the Master clap.gif

    Your skills have always had me in awe of your work Brian,
    and I too long to learn more about Macro than I know right now.

    Thank you for taking the time to do these exercises,
    and explaining things with not only text but images too :D

    You contributions to Dgrin are very very much appreciated.
    Thank you again thumb.gif ...... Skippy
    .

    .
    Skippy (Australia) - Moderator of "HOLY MACRO" and "OTHER COOL SHOTS"

    ALBUM http://ozzieskip.smugmug.com/

    :skippy Everyone has the right to be stupid, but some people just abuse the privilege :dgrin
  • wxwaxwxwax Immoderator Posts: 15,471Registered Users Major grins
    edited April 3, 2007
    Excellent stuff, Lord V. thumb.gif
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
  • juliegrahamjuliegraham Beginner grinner Posts: 8Registered Users Beginner grinner
    edited April 4, 2007
    Brian thank you. As a new Macro shooter, just purchased the Canon 100 macro, you have explained why I am getting the images I am.

    Thanks Now I can move forward.

    graham
  • SkippySkippy Forensic Wannabe Posts: 12,075Registered Users Major grins
    edited April 4, 2007
    Brian thank you. As a new Macro shooter, just purchased the Canon 100 macro, you have explained why I am getting the images I am.

    Thanks Now I can move forward.

    graham

    Graham that is one sweet Lens you have, and I'm glad Brian was able to help you understand more about Macro :D

    Glad you are enjoying Brian's teaching series....... Skippy
    .
    .
    Skippy (Australia) - Moderator of "HOLY MACRO" and "OTHER COOL SHOTS"

    ALBUM http://ozzieskip.smugmug.com/

    :skippy Everyone has the right to be stupid, but some people just abuse the privilege :dgrin
  • cletuscletus Master of Craposition Posts: 1,929Registered Users Major grins
    edited April 4, 2007
    Brian,

    Thanks for putting this together bowdown.gif

    I cannot wait until my D70 gets back so I can start trying out the exercises. I'll be sure to have my macro glass ready to go!
  • ElaineElaine Major grins Posts: 3,532Registered Users Major grins
    edited April 6, 2007
    Thanks for the lesson! I'll be watching for more and trying to follow along. Thanks for being talked into doing this for us! thumb.gif

    Elaine
    Elaine

    Comments and constructive critique always welcome!

    Elaine Heasley Photography
  • MaestroMaestro Amateur at best :-) Posts: 5,395Registered Users Major grins
    edited April 7, 2007
    Thanks. I'll give it a shot.
  • tleetlee Perma Grin Posts: 1,090Registered Users Major grins
    edited April 9, 2007
    I'm sooooooo excited about learning more about macrowings.gifbarbwings.gif!!!
    I will definitely try this exercise, and future ones as well. Thanks to Brian for taking the time to do this!clap.gifclapclap.gif

    T :D

    www.studioTphotos.com

    "Each day comes bearing its own gifts. Untie the ribbons."
    ----Ruth Ann Schubacker
  • k2c1959k2c1959 DA-OLD FART Posts: 123Registered Users Major grins
    edited April 10, 2007
    i too dove head first into this macro stuff. i couldnt stand it anymore, so i have to try it. i also bought the canon 100mm macro lense, extension tubes, the canon mt24 macro twin lites and the stoffen diffusers for the lights. now i just have to learn this stuff...headscratch.gifrolleyes1.gif
    Life is not measured by the breaths you take, but by the moments that take your breath away......

    " I wasn't born in Oklahoma, but I got here as fast as I could! "


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  • DavidTODavidTO Mod Emeritus Thousand Oaks, CAPosts: 19,160Registered Users, Retired Mod Major grins
    edited April 10, 2007
    Listen, people, there's a lot of big talk going on here....but I don't see any pictures! :D
    Moderator Emeritus
    Dgrin FAQ | Me | Workshops
  • ChrisJChrisJ Major grins Posts: 2,159Registered Users Major grins
    edited April 10, 2007
    DavidTO wrote:
    Listen, people, there's a lot of big talk going on here....but I don't see any pictures! :D
    I've done the first part of the exercise, but haven't decided on what I should use for the "real" picture!
    Chris
  • Phil_LPhil_L Major grins Posts: 106Registered Users Major grins
    edited April 11, 2007
    OK, I'll shoot
    Camera D70, lens Sigma 150 f2.8 macro, Speedlight SB800 with (Better)Bounce Card bouncing off the roof.
    Macro 1:1 distance
    Manual exposure SS1/200, Aperture f11
    ISO 200
    Exposure compensation set on flash +3EV (used the histogram)
    Could have opened the aperture a little or directed the flash straight at the subject since I "ran out of" exposure compensation without using the whole range of the histogram.
    Manual focus as per the fastener example.

    Stolen bud off one of my SO's pot plants. eek7.gifne_nau.gif

    Was going to use a fishing lure but could'nt find them. headscratch.gif

    142884425-L.jpg

    100% crop for good measure

    142884344-L.jpg


    Used Aperture F11 to get as much DOF as possible before serious onset of diffraction losses. The flash is obviously doing the exposure since ss 1/200 sec alone is going to get me nowhere at that aperture.
    Focus is on the tip of the bud.

    Exposures in RAW adjusted for WB with a WBcard. Colours tweaked in PS, sensor dust removed with healing brush before save for web. No sharpening.

    Tried to make some use of the rule of thirds in the composition??? Hmmm...headscratch.gif . Oh well.:D

    Edit to add:

    Sorry forgot my manners: great idea this tut, thanks. :-)
  • tleetlee Perma Grin Posts: 1,090Registered Users Major grins
    edited April 11, 2007
    142943005-L.jpg

    I chose this aperture (F8) because I liked how the background was soft, but still had some detail. The soft background makes the tip stand out more. I am glad I did this exercise. I will definitely play around with different apertures more. This will make me think more about the subject I'm shooting, and what kind of end result I want to achieve.

    EXIF

    T :D

    www.studioTphotos.com

    "Each day comes bearing its own gifts. Untie the ribbons."
    ----Ruth Ann Schubacker
  • Lord VetinariLord Vetinari Smugbug Posts: 15,462Registered Users Major grins
    edited April 11, 2007
    Phil_L wrote:
    Camera D70, lens Sigma 150 f2.8 macro, Speedlight SB800 with (Better)Bounce Card bouncing off the roof.
    Macro 1:1 distance
    Manual exposure SS1/200, Aperture f11
    ISO 200
    Exposure compensation set on flash +3EV (used the histogram)
    Could have opened the aperture a little or directed the flash straight at the subject since I "ran out of" exposure compensation without using the whole range of the histogram.
    Manual focus as per the fastener example.

    Stolen bud off one of my SO's pot plants. eek7.gifne_nau.gif

    Was going to use a fishing lure but could'nt find them. headscratch.gif

    142884425-L.jpg

    Used Aperture F11 to get as much DOF as possible before serious onset of diffraction losses. The flash is obviously doing the exposure since ss 1/200 sec alone is going to get me nowhere at that aperture.
    Focus is on the tip of the bud.

    Exposures in RAW adjusted for WB with a WBcard. Colours tweaked in PS, sensor dust removed with healing brush before save for web. No sharpening.

    Tried to make some use of the rule of thirds in the composition??? Hmmm...headscratch.gif . Oh well.:D

    Edit to add:

    Sorry forgot my manners: great idea this tut, thanks. :-)

    Excellent example- nice DOF and good composition- accentuates the flower bud nicely. The wood grain also works nicely. Thanks for being the brave first to post back :)
    Brian V.
  • Lord VetinariLord Vetinari Smugbug Posts: 15,462Registered Users Major grins
    edited April 11, 2007
    tlee wrote:
    142943005-L.jpg

    I chose this aperture (F8) because I liked how the background was soft, but still had some detail. The soft background makes the tip stand out more. I am glad I did this exercise. I will definitely play around with different apertures more. This will make me think more about the subject I'm shooting, and what kind of end result I want to achieve.

    EXIF

    Another excellent example- lovely sharp focus and detail on the tip but nice DOF keeping the rest of the connector OOF.- Think I might learn something from these examples :)
    Brian V.
  • DalantechDalantech No cropping zone... Posts: 1,519Registered Users Major grins
    edited April 13, 2007
    My turn ;) Sorry it's taken me so long to post -entirely too much Real Life getting in the way of the things that I'd rather be doing...

    I stopped at my favorite abandoned lot on the way home from work yesterday and caught this guy licking his fingers -messy eater. The angle was the best I could get on this one -he let me take all of three frames before deciding to move on. Shot with a 1.4 teleconverter + 25mm extension tube + 100mm macro lens for about twice life size. Manual mode F11 (about as high as I want to go with all that glass in the way), 1/200, and ISO 100. MR-14EX ring flash set to a 4:1 ratio (to create shadows so the image doesn't look flat) and -1/3 FEC (cuts down on the glare and helps to keep from blowing out the highlights).

    Hand held, but that's kinda deceptive. At F11 and ISO 100, plus losing a full stop with the teleconverter, if the flash doesn't fire then the scene will be completely black. The photo receptors on a digital camera's sensor are like buckets for light and you have to fill them up to get a proper exposure. A half full bucket and the image is badly under exposed, and if the bucket gets too full then the image will be over exposed. Without the flash the bucket is almost completely empty, so the flash is really the only source of light in an image like this one. Since the flash duration is only 1/1200 of a second the flash becomes a virtual shutter -the fact that the actual shutter was open for 1/200 of a second doesn't matter, since there is very little natural light reaching the camera's sensor anyway...

    I also set the flash to second curtain sync so that the strongest light source is leaving the last "imprint" on the sensor -helps to make hand held flash shots a little sharper.

    Sorry for the long post -but this is a learnin' thread mwink.gif

    143200337-L.jpg
    My SmugMug Gallery

    Looking for tips on macro photography? Check out my Blog: No Cropping Zone.
  • Lord VetinariLord Vetinari Smugbug Posts: 15,462Registered Users Major grins
    edited April 13, 2007
    Dalantech wrote:
    My turn ;) Sorry it's taken me so long to post -entirely too much Real Life getting in the way of the things that I'd rather be doing...

    I stopped at my favorite abandoned lot on the way home from work yesterday and caught this guy licking his fingers -messy eater. The angle was the best I could get on this one -he let me take all of three frames before deciding to move on. Shot with a 1.4 teleconverter + 25mm extension tube + 100mm macro lens for about twice life size. Manual mode F11 (about as high as I want to go with all that glass in the way), 1/200, and ISO 100. MR-14EX ring flash set to a 4:1 ratio (to create shadows so the image doesn't look flat) and -1/3 FEC (cuts down on the glare and helps to keep from blowing out the highlights).

    Hand held, but that's kinda deceptive. At F11 and ISO 100, plus losing a full stop with the teleconverter, if the flash doesn't fire then the scene will be completely black. The photo receptors on a digital camera's sensor are like buckets for light and you have to fill them up to get a proper exposure. A half full bucket and the image is badly under exposed, and if the bucket gets too full then the image will be over exposed. Without the flash the bucket is almost completely empty, so the flash is really the only source of light in an image like this one. Since the flash duration is only 1/1200 of a second the flash becomes a virtual shutter -the fact that the actual shutter was open for 1/200 of a second doesn't matter, since there is very little natural light reaching the camera's sensor anyway...

    I also set the flash to second curtain sync so that the strongest light source is leaving the last "imprint" on the sensor -helps to make hand help flash shots a little sharper.

    Sorry for the long post -but this is a learnin' thread mwink.gif

    Lovely shot John - good use of fairly limited DOF focusing attention on the head.
    Not sure I understand the use of 2nd curtain flash under these circumstances if the flash is virtually the only source of light- surely it wouldn't matter when the flash fired?
    Brian V.
  • DalantechDalantech No cropping zone... Posts: 1,519Registered Users Major grins
    edited April 13, 2007
    Lovely shot John - good use of fairly limited DOF focusing attention on the head.
    Not sure I understand the use of 2nd curtain flash under these circumstances if the flash is virtually the only source of light- surely it wouldn't matter when the flash fired?
    Brian V.

    Absolutely right -just set as a precaution in case I'm shooting close to life size. I don't always use that rig at max magnification and using second curtain sync helps to keep the image sharp if I get close to an ambient light exposure. I knew I didn't explain that right... headscratch.gif
    My SmugMug Gallery

    Looking for tips on macro photography? Check out my Blog: No Cropping Zone.
  • Antonio CorreiaAntonio Correia Always learning Setubal - PortugalPosts: 6,183Registered Users Major grins
    edited May 15, 2007
    Brian.
    Good morning. :D
    I have been reading your lessons about macro photography.
    In fact I only read the 1.st one so far. mwink.gif
    I don't have any experience in this kind of photography, but I would like to try, and that's what I am going to do.

    I don't have a macro lens.
    I own the Canon 24-70 f/2.8 L USM which has to be enought for the moment :D and the Canon 70-200 f/2.8 L USM IS which - with the lens in front - is very capable, so I read.
    But for the moment I'll keep my equipment as it is.
    I hope to be able to post some work soon.clap.gif
    Thank you for the very nice tutorials.
    Regards. thumb.gif
    All the best ! ... António Correia - Facebook
  • Antonio CorreiaAntonio Correia Always learning Setubal - PortugalPosts: 6,183Registered Users Major grins
    edited May 16, 2007
    It really doesn't work ! ne_nau.gifOr it's just me ... ne_nau.gif
    I don't have macro lens as I told before. So, I have choosen a small bottle 5 cms hight and made some pictures.
    I did as suggested by Brian and I had poor results.
    I couldn't even get myself convinced of the diffraction softning. Too bed.:cry
    But I am going to try that focus stacking. It looks quite interesting for landscapes.
    153022457-S.jpg 153023693-S.jpg
    153022543-S.jpg153023902-S.jpg

    Click on pictures for a larger view, please.
    The photos don't have any treatment. They are straight from RAW.
    All the best ! ... António Correia - Facebook
  • Lord VetinariLord Vetinari Smugbug Posts: 15,462Registered Users Major grins
    edited May 16, 2007
    It really doesn't work ! ne_nau.gifOr it's just me ... ne_nau.gif
    I don't have macro lens as I told before. So, I have choosen a small bottle 5 cms hight and made some pictures.
    I did as suggested by Brian and I had poor results.
    I couldn't even get myself convinced of the diffraction softning. Too bed.:cry
    But I am going to try that focus stacking. It looks quite interesting for landscapes.

    Hi Antonio,
    Not sure how the diffraction softening applies to your lens system at that magnification, but there is some good info here
    http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm#

    I suspect you would need to compare shots at F11 and F22 at 100% crop to notice the diffraction softening (ie at about 200 to 400% in photoshop)

    Worth trying the focus stacking because that can be used for non-macro shots if DOF is a problem with static subjects- actually it can be fun to do it with things that have moved and see what it makes of it (eg people)

    Brian V.
  • Antonio CorreiaAntonio Correia Always learning Setubal - PortugalPosts: 6,183Registered Users Major grins
    edited May 16, 2007
    Hi Antonio,
    Not sure how the diffraction softening applies to your lens system at that magnification, but there is some good info here
    http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm#

    I suspect you would need to compare shots at F11 and F22 at 100% crop to notice the diffraction softening (ie at about 200 to 400% in photoshop)

    Worth trying the focus stacking because that can be used for non-macro shots if DOF is a problem with static subjects- actually it can be fun to do it with things that have moved and see what it makes of it (eg people)

    Brian V.
    Hello Brian.
    Thank you for the link and the comment. thumb.gif
    In fact I have been to Cambridge in Colour (and in Cambridge also) some time ago. Important and interesting site (and beautiful, gorgeous city). :D
    I will try the photo stacking with other shots.
    I will remember to show the photos and experiments using this technique.
    Cheers.
    All the best ! ... António Correia - Facebook
  • DalantechDalantech No cropping zone... Posts: 1,519Registered Users Major grins
    edited May 21, 2007
    ...I don't have macro lens as I told before...

    That's why you can't see it. As magnification increases the effective Fstop also increases. Brian could give you specifics, but I want to say that shooting life size at F11 is like shooting a scenic at F22. Going past life size causes the effective Fstop to climb even higher...
    My SmugMug Gallery

    Looking for tips on macro photography? Check out my Blog: No Cropping Zone.
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