/////What is this dust? How to eliminate please.
What is this dust? How to eliminate please.2017-09-08T16:58:52+02:00

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What is this dust? How to eliminate please.

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  • Keith Baxter
    Participant
    Post count: 143

    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.

    [ATTACH=CONFIG]9594[/ATTACH]

  • elsahoffmann
    Moderator
    Post count: 3716

    Flash.

  • SimonDP
    Moderator
    Post count: 2148

    Flash defecting off pigments in the petals

  • Keith Baxter
    Participant
    Post count: 143

    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?

  • elsahoffmann
    Moderator
    Post count: 3716

    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 ๐Ÿ™‚

    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

  • SimonDP
    Moderator
    Post count: 2148

    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…

  • Keith Baxter
    Participant
    Post count: 143

    @simondp 297752 wrote:

    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/gallery/showphoto.php?photo=374354&title=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.

  • elsahoffmann
    Moderator
    Post count: 3716

    what sharpening did you do?

  • Keith Baxter
    Participant
    Post count: 143

    @elsahoffmann 297754 wrote:

    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.

  • elsahoffmann
    Moderator
    Post count: 3716

    keith – editing can be an issue – it highlights any shortcomings or artifacts

  • Keith Baxter
    Participant
    Post count: 143

    @elsahoffmann 297756 wrote:

    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.

  • elsahoffmann
    Moderator
    Post count: 3716

    Have fun Keith.

  • bomtek
    Moderator
    Post count: 1048

    @keith Baxter 297755 wrote:

    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

  • Keith Baxter
    Participant
    Post count: 143

    @bomtek 297764 wrote:

    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/gallery/showphoto.php?photo=374369&title=orchid&cat=548

    http://www.outdoorphoto.community/gallery/showphoto.php?photo=374314&title=orchid&cat=548

    Four stack images.

    http://www.outdoorphoto.community/gallery/showphoto.php?photo=374316&title=orchid&cat=500

    http://www.outdoorphoto.community/gallery/showphoto.php?photo=374368&title=oncidium-tallahassee-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.

  • Leo Theron
    Participant
    Post count: 1582

    @keith Baxter 297768 wrote:

    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/gallery/showphoto.php?photo=374369&title=orchid&cat=548

    http://www.outdoorphoto.community/gallery/showphoto.php?photo=374314&title=orchid&cat=548

    Four stack images.

    http://www.outdoorphoto.community/gallery/showphoto.php?photo=374316&title=orchid&cat=500

    http://www.outdoorphoto.community/gallery/showphoto.php?photo=374368&title=oncidium-tallahassee-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.

  • Keith Baxter
    Participant
    Post count: 143

    @leo Theron 297771 wrote:

    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/albums/72157632849835726/page2

  • Keith Baxter
    Participant
    Post count: 143

    This is where I would like to venture. Now to source a reasonably priced 365nm light source. ๐Ÿ™‚

    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?

  • bomtek
    Moderator
    Post count: 1048

    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 ๐Ÿ™‚

    @keith Baxter 297778 wrote:

    This is where I would like to venture. Now to source a reasonably priced 365nm light source. ๐Ÿ™‚

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

    http://www.holovachov.com/p187256964

  • Keith Baxter
    Participant
    Post count: 143

    @bomtek 297779 wrote:

    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 ๐Ÿ™‚

    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.com/content/index.php/topic/138-sticky-uv-photography-intro-cams-mods-lights-links/

  • bomtek
    Moderator
    Post count: 1048

    @keith Baxter 297780 wrote:

    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.com/content/index.php/topic/138-sticky-uv-photography-intro-cams-mods-lights-links/

    Ive been reading that site for months now and still haven’t gotten through everything. Great resource indeed.

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