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  1. #1
    Frequent Member Keith Baxter's Avatar
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    Default What is this dust? How to eliminate please.

    I am getting a lot of these white speckles/dust on the images. What causes these and how do I eliminate them. 100mm macro lens. 0.6 sec at f/22 100 iso and flash did fire.

    Are these dust marks on the sensor? Or dust on the object.

    The image was taken because the sunlight was shining through the kitchen door and the colors looked amazing. Wife held the red BG.

    What puzzles me is that the BG does not have these speckles.

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    Last edited by bomtek; 13-09-2017 at 02:07 PM.

  2. #2
    Premium Member elsahoffmann's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Flash.
    Nudity is the most Avant Garde form of dress

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  3. #3
    Administrator SimonDP's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Flash defecting off pigments in the petals
    Simon Du Plessis

    www.actionimage.co.za simondp@actionimage.co.za

    (I'll keep on shooting, and one of these days I'll get it right!)
    Contact me for training in Beginners, Macro, Wildlife or Sport & Action photography
    Please e-mail or PM me should you wish to have my comments on a specific image, or to comment/ask questions on my crits)

  4. #4
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Thank you for helping me once again and giving me the cause Elsa and Simon. This brings the next questions.



    1) What needs to be done to prevent this from happening?

    2) Can the splatter be fixed easily in post should I want to keep the image?

    3) Is it acceptable in photography and/or should I just discard the image?

  5. #5
    Premium Member elsahoffmann's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Keith - I cant tell you what is the *right thing to do. Simon will probably be better at telling you what works best for macro.

    For me personally - I dont use flash. In general I do not like flash - whenever you use a flash - it has that "look" which I dont like. Yes I use studio flash IN STUDIO but thats another topic.

    I prefer ambient light for flowers - and add a reflector which makes a huge difference. For some this will not be practical - especially if there is no ambient light

    I wouldnt try and "fix" this in post processing though. At the very most - IF possible - reduce highlights but that wont work in your image above, IMHO
    Nudity is the most Avant Garde form of dress

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  6. #6
    Administrator SimonDP's Avatar
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    Default Re: What is this dust? How to eliminate please.

    You decide if it works for you. Yes you can spot remove it, I wouldn't bother. Seldom will you get to do Macro without using flash or extra lighting. You cannot prevent it from happening, you can lessen the effect by using a PL filter at times or not using any flash...
    Simon Du Plessis

    www.actionimage.co.za simondp@actionimage.co.za

    (I'll keep on shooting, and one of these days I'll get it right!)
    Contact me for training in Beginners, Macro, Wildlife or Sport & Action photography
    Please e-mail or PM me should you wish to have my comments on a specific image, or to comment/ask questions on my crits)

  7. #7
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by SimonDP View Post
    You decide if it works for you. Yes you can spot remove it, I wouldn't bother. Seldom will you get to do Macro without using flash or extra lighting. You cannot prevent it from happening, you can lessen the effect by using a PL filter at times or not using any flash...
    Simon Thank you for always helping. Your insight is appreciated. I am thinking that the issue is not only "flash".

    Sorry I could not go through the pain of resizing and posting here so i posted in the gallery. This image also shows those same spectral splatter and no flash was used. Just the natural golden sunlight. A blue BG was used. You can see the EXIF from the link.

    http://www.outdoorphoto.community/ga...orchid&cat=548

    I do believe that the splatter is caused by light. Not sure it is by flash though as this image would suggest not. Taken hurriedly as the sun light went down. Please help me understand this. I want to get this right.

    My inspiration comes from Denise Ippolito's Images.

  8. #8
    Premium Member elsahoffmann's Avatar
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    Default Re: What is this dust? How to eliminate please.

    what sharpening did you do?
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  9. #9
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by elsahoffmann View Post
    what sharpening did you do?
    In LR sharpened to 45. No colors were changed. Just added a little contrast. And tried to remove the "splatter" with the noise slider. The exposure was opened as the image was under exposed.

  10. #10
    Premium Member elsahoffmann's Avatar
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    Default Re: What is this dust? How to eliminate please.

    keith - editing can be an issue - it highlights any shortcomings or artifacts
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  11. #11
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by elsahoffmann View Post
    keith - editing can be an issue - it highlights any shortcomings or artifacts
    Yup Elsa 100's, I think I need to have a serious look at the editing process I am using and the image selection. Anyway I am spending the day taking images of my Orchid's trying out different things.

    Thank you so much for all the help. I think I am getting there slowly.

    BTW I did purchase some continuous lighting for indoor shooting on Friday. Seems to help. Just two 20w led bulbs on stands with a white umbrella.

  12. #12
    Premium Member elsahoffmann's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Have fun Keith.
    Nudity is the most Avant Garde form of dress

    www.elsahoffmann.co.za
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  13. #13
    ODP Assistant bomtek's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by Keith Baxter View Post
    In LR sharpened to 45. No colors were changed. Just added a little contrast. And tried to remove the "splatter" with the noise slider. The exposure was opened as the image was under exposed.
    With the Canon 100mm Marco lens you shouldn't be sharpening to 45 in LR. I also wouldn't shoot above f16 as lens diffraction may be the reason you're feeling the need to sharpen so much. If DOF is a problem, explore focus stacking.

    If you want to limit light reflection from your flash or other source, consider using a diffuser. Gary Fongs are big but work well. The small soft box types may also help. A dedicated macro flash such as the MT14 or twin head MT24 may also make life easier.

    And no harm in having the sensor cleaned regardless but you can check for dust by shooting blue sky at F22 - F32.

    Good luck

  14. #14
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by bomtek View Post
    With the Canon 100mm Marco lens you shouldn't be sharpening to 45 in LR. I also wouldn't shoot above f16 as lens diffraction may be the reason you're feeling the need to sharpen so much. If DOF is a problem, explore focus stacking.

    If you want to limit light reflection from your flash or other source, consider using a diffuser. Gary Fongs are big but work well. The small soft box types may also help. A dedicated macro flash such as the MT14 or twin head MT24 may also make life easier.

    And no harm in having the sensor cleaned regardless but you can check for dust by shooting blue sky at F22 - F32.

    Good luck
    Thank you so much for your thoughts Terry. Taking note of what you say.

    I have dabbled in focus stacking. The first two images are 6 image stacks and the third is a four image stack. Using Zerene Stacker to process. The EXIF will show the file name ....ZS_retouched... I am very new to this process and technique but I will no doubt continue to perfect or ditch the concept.

    Lighting and lighting type is very new to me. I am taking in a knowledge overload that is sometimes confusing. Just when I think I have got it nailed Murphy pokes his tong out.

    Anyway here are the stacked images I talk of.

    Six stack images.

    http://www.outdoorphoto.community/ga...orchid&cat=548

    http://www.outdoorphoto.community/ga...orchid&cat=548


    Four stack images.

    http://www.outdoorphoto.community/ga...orchid&cat=500

    http://www.outdoorphoto.community/ga...orchid&cat=548


    Sensor cleaning is something that is a consideration. Should I do it myself.... I would like to, and think I have the ability to as my background involved instrument and watch repair many years back. Need to see how it is done before taking the plunge.

  15. #15
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by Keith Baxter View Post
    Thank you so much for your thoughts Terry. Taking note of what you say.

    I have dabbled in focus stacking. The first two images are 6 image stacks and the third is a four image stack. Using Zerene Stacker to process. The EXIF will show the file name ....ZS_retouched... I am very new to this process and technique but I will no doubt continue to perfect or ditch the concept.

    Lighting and lighting type is very new to me. I am taking in a knowledge overload that is sometimes confusing. Just when I think I have got it nailed Murphy pokes his tong out.

    Anyway here are the stacked images I talk of.

    Six stack images.

    http://www.outdoorphoto.community/ga...orchid&cat=548

    http://www.outdoorphoto.community/ga...orchid&cat=548


    Four stack images.

    http://www.outdoorphoto.community/ga...orchid&cat=500

    http://www.outdoorphoto.community/ga...orchid&cat=548


    Sensor cleaning is something that is a consideration. Should I do it myself.... I would like to, and think I have the ability to as my background involved instrument and watch repair many years back. Need to see how it is done before taking the plunge.
    Keith,

    What you are seeing in your image is elements on the petals that are fluorescing (Emits visible light when lit with UV light) You will see the same with those petals in sunlight. Subdued and or reflected light - flash from a paper reflector, for example, will reduce or eliminate the problem.

    Flowers have patterns in their petals that are only visible in UV light - and it is used by insects and bees when they approach the flower to get to the nectar and pollinate the flower.
    Best,

    Leo Theron
    ... see my pictures HERE

  16. #16
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by Leo Theron View Post
    Keith,

    What you are seeing in your image is elements on the petals that are fluorescing (Emits visible light when lit with UV light) You will see the same with those petals in sunlight. Subdued and or reflected light - flash from a paper reflector, for example, will reduce or eliminate the problem.

    Flowers have patterns in their petals that are only visible in UV light - and it is used by insects and bees when they approach the flower to get to the nectar and pollinate the flower.
    Thank you Leo for your explanation and advice. I am truly grateful to you, and all the contributors who continue to assist and explain to me the causes and ways to produce better images.

    I also want to venture into macro luminescence photography at some point. This goal is inspired by luminescence one sees in the corals in aquaria. But I need to understand and learn the basic principals of lighting first.

    Perhaps I am impatient and want to try too many things before perfecting one discipline. Going to try and restrain myself.....

    EDIT.. This is where I want to get to. Not the microscopic photography part just the Fluorescence part. https://www.flickr.com/photos/pwnell...49835726/page2
    Last edited by Keith Baxter; 12-09-2017 at 09:23 PM.

  17. #17
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    This is where I would like to venture. Now to source a reasonably priced 365nm light source.

    Yes Leo, Thank you. What you say is 100's as I can see the effect in these images.

    http://www.holovachov.com/p187256964


    EDIT... I do NOT have a UV filter on the 100mm lens I am using. Removed it. Would it help to put it back for normal macro shooting?

  18. #18
    ODP Assistant bomtek's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Keith

    Capturing usable UV light with a standard camera is almost impossible - all it does is cause a haze across the image and that, with the advent of digital cameras, is all but a thing of the past.

    Your sensor (depending on which one) can capture UV light down to around 200nm. In order to prevent this contaminating visible light images the manufacturers have place numerous filters in front of the sensor. To add to this, glass naturally reflects UV light and this is the limiting factor. True UV lenses are made of quartz.

    Without blocking visible light and infrared you're not going to achieve anything usable as a UV image. Another thing to remember is that any colour you see in a UV image is false colour.

    Im using a Sony A5000 full spectrum body with a dedicated UV filter (340nm - 385nm).
    Best light source is the sun



    Quote Originally Posted by Keith Baxter View Post
    This is where I would like to venture. Now to source a reasonably priced 365nm light source.

    Yes Leo, Thank you. What you say is 100's as I can see the effect in these images.

    http://www.holovachov.com/p187256964

  19. #19
    Frequent Member Keith Baxter's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by bomtek View Post
    Keith

    Capturing usable UV light with a standard camera is almost impossible - all it does is cause a haze across the image and that, with the advent of digital cameras, is all but a thing of the past.

    Your sensor (depending on which one) can capture UV light down to around 200nm. In order to prevent this contaminating visible light images the manufacturers have place numerous filters in front of the sensor. To add to this, glass naturally reflects UV light and this is the limiting factor. True UV lenses are made of quartz.

    Without blocking visible light and infrared you're not going to achieve anything usable as a UV image. Another thing to remember is that any colour you see in a UV image is false colour.

    Im using a Sony A5000 full spectrum body with a dedicated UV filter (340nm - 385nm).
    Best light source is the sun
    Thank you for your information Terry. I spent the morning browsing the net and found this interesting site. I do not see myself modifying my 7Dmk2 but my 350D might be an option.

    Anyway here is the interesting link for those who might want to go down this rout.

    http://www.ultravioletphotography.co...-lights-links/

  20. #20
    ODP Assistant bomtek's Avatar
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    Default Re: What is this dust? How to eliminate please.

    Quote Originally Posted by Keith Baxter View Post
    Thank you for your information Terry. I spent the morning browsing the net and found this interesting site. I do not see myself modifying my 7Dmk2 but my 350D might be an option.

    Anyway here is the interesting link for those who might want to go down this rout.

    http://www.ultravioletphotography.co...-lights-links/
    Ive been reading that site for months now and still haven't gotten through everything. Great resource indeed.

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