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Clinical photography guidance

Discussion in 'General Issues and Discussion Forum' started by Mrs Brightside, Dec 20, 2011.


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    Hi all,

    I'm a regular viewer on here, but have never posted (am a little shy!!!)

    MANY, many months ago, when the VP 'needling' thread was first started, somebody very kindly posted some guidance on clinical photography, in order to maximise the quality of the images (I have a feeling it MIGHT have been Mr Doug Ritchie???)

    I have a project up and coming, which will require me to take some photos of VPS; does anyone have any experience and/or advice on how to achieve the best results please?

    In addition, does anybody have any guidance on objectively measuring the dimensions of lesions, in order to chronicle a course of treatment in a patient's notes? Is there a way of 'tracing' them?

    I'd REALLY appreciate any feedback that any of you may have, in particular if you know of any published guidance on either query...

    Thanks in advance...:santa2:
     
  2. efuller

    efuller MVP


    It's hard to give advice without knowing how much you already know about photography. For example, do you know what a macro lens is? Or can you find the macro setting on your camera?

    A quick google of "measuring area in a picture" brought up some interesting results. Has anybody used imageJ?

    Eric
     
  3. Brightside:

    If you can answer these questions for me first, then I would be happy to help you:

    1. What is your first name?

    2. What kind of camera and camera equipment do you already own? What is their exact name and model number?

    3. What type of photographic experience do you have? Have you taken any classes or done any reading on photography?

    4. Do you know anything about the following photographic terms: F-stop, aperture, shutter speed, depth of field, megapixels, single lens reflex, viewfinder, digital vs film camera, focal length?

    By the way, I doubt that Doug Ritchie gave any advice on photography here...however I did give some advice on photography in the vp needling thread a few years ago. I taught photographic processing techniques and basic photographic terminology and theory many years ago during my undergraduate years back when I was doing all of my own darkroom work and processing with black and white film at UC Davis (i.e. way before digital cameras were invented).
     
  4. Hi Eric,

    thanks for the prompt reply. I know about the macro setting on my camera - would you recommend that I use this?

    Mrs B
     
  5. Kevin, please accept my apologies; the thread was a long time ago and I really wasn't sure who had given us all the benefit of their experience - it would appear that yours is fairly vast!

    In response to your questions:

    1) First name Rachel :D
    2)Camera is a Sony Cybershot 7.2 mega pixel DSC-W70
    3) I've got absolutely no 'formal' knowledge of photogaphy at all (no classes, reading etc)
    4) I know a little about shutter speeds, what an SLR camera is, know nothing about focal lengths or F-stop, but can always google that!

    I get pretty good 'snaps' when using the camera, even using it to photograph motorsports moving at high speed, but when it comes to snapping feet up nice and close to try to get a lot of detail, it all goes horribly wrong! :confused:

    Where do I start please?

    Rachel/Mrs Brightside
     
  6. Rachel:

    I have attached your owner's manual in case you have forgotten where your owner's manual is located. This is always a good place to start learning about the specific functions of your particular camera.

    You have two choices when taking close-up photos of the foot with your camera:

    1. Macro setting (which is a flower icon on your camera) will let you focus as long as the lens is at least 2.2 cm from the object you are photographing.

    2. Normal setting (the default) will let you focus up close as long as the lens is at least 20 cm from the object you are photographing.

    You should be able to use wide angle to telephoto functions on the camera to see which focal length of your lens (i.e. small focal lengths are for wide angle shots, larger focal lengths are for telephoto shots) allows you to focus the best on the object, or foot, in either macro or normal setting.

    The key to any good close-up photo is the amount, direction, and quality of light that is striking the object which you are photographing. With more light, the images will nearly always be better with close-up photography since greater light will increase the F-stop of the lens. [The F-stop is the aperture, or opening, which lets a certain amount of light through the lens. The higher the F-stop, the smaller the lens opening (i.e. smaller aperture) which means that less light that will enter the lens but will also mean that you will have a greater "depth of field". Depth of field is the close and far distance from the lens where all objects will be in focus. Therefore, more light means a smaller F-stop which means also greater depth of field and the more likely your close-up shot will be in sharp focus.]

    One of the problems with using the macro function in digital cameras such as yours is that getting proper lighting can be quite tricky since most times the internal camera flash, when used in macro, produces an uneven and even "dimensionless" photograph, with skin line detail not being well-defined. The macro (i.e. close-up) function of your camera does allow you to get very close to the object that you are photographing with the camera. I would think the macro setting of your camera would would be your best bet for photographing skin lesions on the plantar foot.

    Probably the best way to photograph a verruca plantaris (vp) lesion is to bring in a examination light into the room and shine it from the lateral side of the foot directly at the lesion so that the light beams are hitting the skin lines on the plantar foot from an oblique angle. This oblique angling of the light will 1) allow you to create good and even lighting on the surface of the foot you want to photograph without the lens from your camera creating a shadow on the plantar foot , and 2) will create some slight shadows in the troughs of the skin lines so that skin line detail will be enhanced due to increased contrast within the skin lines. [Contrast is the difference between the light areas and dark areas of any photograph.]

    Then, using the macro setting on your camera, take 5-10 shots with the body of your camera (the camera body is the flat box of the camera where the lens attaches) oriented parallel to the surface of the plantar skin where the vp is located. Keeping the plane of the camera parallel to the skin surface will increase the chance that all the skin detail will be in focus since this will keep the plantar skin close to being within the same focal plane. [The focal plane of the lens is the optimum plane of focus for a given lens setting.] Use the largest megapixel image you can with your camera (i.e. more megapixels) since this will give you the greatest image detail and will allow you to crop the photo down to a good-looking image with less chance of loss of clarity of image. [A pixel is one very small rectangle of color which collectively makes the image seen in a digital camera photograph. A megapixel is one million pixels. Your camera, with each shot, takes 7,077,888 rectangles of color (i.e. pixels). When these pixels are all placed next to each other within a grid, what is created is the photographic image that you shot. Isn't technology cool?!]

    The photo I have attached below is a photo I just took of my left thumb with my desk lamp shining from the side onto my thumb, with my Canon PowerShot SD940 digital camera set to macro. The lens to thumb distance was about 2.5-3.0 cm. I think our two digital cameras are very similar in function and quality.

    As you can see in the photo, the skin lines are more visible where the light is shining onto my thumb more obliquely from the side, hitting the skin ridges at such an angle to optimize the contrast and "feeling of depth" within the image. The angulation of light will be the critical detail as to whether your vp photos look average versus whether your vp clinical photos look great. Also not that on top and sides of my thumb, the skin is slightly out of focus. This is because the very top and sides of my thumb is not within the depth of field for proper focus since it is further away from the lens.

    You will need to experiment with lighting angulation onto the plantar skin until the ridge detail looks best in the viewfinder of the camera. The trick to this type of photogarphy is to enhance the contrast with optimizing the angulation of lighting, hold your camera steady while composing the shot, get the camera focused, and then take the shot.

    Practice at home with a desk lamp shining on a foot from one of your family/friends until you get the kind of image detail that you want. Then go practice a few photos at work with your patients. Always take lots of photos (at least 10 per lesion) from different lighting angles and with different distances from the foot to see what looks the best. Good photographers will take notes of what worked best so that they can reproduce the same lighting conditions repeatedly.

    Attach some of your photos here in this thread on Podiatry Arena when you get a chance and I will give you further suggestions on how to improve your clinical photos.

    Pretty soon, Rachel, you will be teaching others how to take better clinical photos since all your friends will be amazed at how great all your photos look!

    Hope this helps and Merry Christmas.:drinks:santa:
     
  7. Admin2

    Admin2 Administrator Staff Member

    Last edited by a moderator: Sep 22, 2016
  8. Depth of Field in Macro Photography

    The term depth of field refers to the distance range of objects from the lens that will be in focus in a photograph. In the example I made tonight, I held a wooden ruler to the lens of my digital camera set in macro (i.e. close-up) mode so that a much more clear representation of the term "depth of field" could be seen. Notice that from about the 2.7 cm to 3.3 cm marks on the ruler, the lines of the ruler are in focus while the lines closer than the 2.7 cm mark and further than the 3.3 cm mark are out of focus. Therefore, in this example, my depth of field in this shot is a little less than 6 mm (from 2.7 to 3.3 cm) while in macro mode with this amount of light shining on the ruler.

    The lesson to be learned from this photo when making macro shots: the depth of field in macro shots is extremely small, in millimeters, so that the more light you can shine onto the subject, whether it is with an electronic flash or another available light source, the greater will be the f-stop, the greater will be the depth of field and the greater the chance that more of your subject will be in good focus.
     
  9. gdenbyUK

    gdenbyUK Active Member

    Hi Rachel,

    I use clinical digital photography all the time in my private practice, to monitor all infections and resolution of lesions such as plantar warts, fungal nails or suspicious melanoma. They are highly beneficial when writing GP referral letters - they get you noticed!

    I concur with the above recommendation for nearby lighting - I have a magnifying lamp that I bring just behind the camera, always in macro mode when 2-3 cm away from the foot.

    It is critical that you have a printed scale within the image, in order to judge any change in size over time. Thus you can see from the attached image, I always include a small sticky label with a millimetre scale, the date and the client's initials.

    [​IMG]

    When recording warts, you may wish to take a presentation picture and also another after debridement, since some healing or bruising is deep beneath the surface.

    Another consideration is where you are going to store the pictures and how much space a large number of them can consume and how you are going to file them. I use an on-line patient managements system called PracticePal, so I upload them onto the net, attached to the respective client records. They are automatically secured and backed-up. A memory stick by comparison is very fragile and too easily lost (as is leaving them on the camera!). I set the camera's 'image size' to be about 2 Megapixels, which results in a compressed .JPG image of about 400 Kbytes - it does NOT take ages to transfer, but gives plenty of detail upon which to zoom-in.

    Regards, Gary Denby at www.footwisepodiatry.co.uk
     
  10. gdenbyUK

    gdenbyUK Active Member

    P.S. You may also wish to consider registration under the Data Protection Act in the UK, if recording electronic client details (my clinic has been so registered since its start in 2005).

    There is also the thorny issue of (written?) consent for digital recording. My site indicates that consent is deemed for all simple procedures, is written for more complex courses and is sought verbally for GP referral letters when discussing the treatment plan...

    Regards
    Gary
     
  11. AngieR

    AngieR Active Member

    Gary,

    I have struggled to get a picture uploaded to Practice Pal, any suggestions on where I may be going wrong? I wonder if the pixels are too large.

    Angie
     
  12. gdenbyUK

    gdenbyUK Active Member

    Hi Angie, You may be correct about the file size of your pictures (this may be causing a time-out if using a slow internet connection). I'll contact you by email so you can send me your example picture and help determine where you may be going wrong. I've been uploading pictures to Practice Pal for the past two years on a weekly basis... Regards Gary
     
  13. Kevin,

    MANY thanks for taking the time to go through this, I'm hoping it's of benefit to a number of us, not just me! You've managed to explain, in terms that I understand, what my user manual failed to do, which is to dissect the terminology and work up from basics. So often an existing level of knowledge is presumed, and if you don't have it, you get left behind.

    I've been practising, (on my thumb!!!) and am producing more consistent images, whereas previously, if I achieved a good shot it was due to luck, rather than judgement. I think the main factor for me to consider is lighting, having it positioned obliquely, from the side.

    My problem is that the study design states that images need to be comparable (which you'd expect), and that I need to take them from the same angle/position, but this doesn't lead to the best images every time. :confused: I suppose it's just practice, practice, practice eh? I'll get there, with your help. My next task is to upload some of what I've taken onto here for your, ahem, 'consideration'!! (highly embarrased!)

    MUCH appreciated Kevin, and sorry for the delayed reply, I've been 'incommunicado' over the Christmas period. I trust you and your nearest and dearest had a very pleasant break.

    Rachel.
     
  14. Fantastic advice Gary, many thanks. I will certainly look into PracticePal (this is the first time I've used clinical photography within the clinic).

    I note with interest tat you recommend bringing your magnifying lamp just behind your camera, as opposed to what Kevin suggests obliquely to the side - do you know technically what difference this would make? I will have a practice with both and see what happens....

    Rachel.
     
  15. Gary,

    Yes, we're registered under the Data Protection Act, can't be too careful;)

    We use the SOCAP pro-forma for all written consent, including simple VP treatments, needlings, LAs, nail surgery, clinical photography, digital recording of gait analysis etc.

    Rachel.
     
  16. Yeah, but you got parallax error there between the scale and the lesion and the camera... Just an observation. Probably Ok if its just for your records, if this came into me on a paper for review, I'd say: "Yeah, but you got parallax error there between the scale and the lesion and the camera". Or something like that.

    P.S. clearly you don't need the date bit on your label, since the camera will stamp that for you. http://www.youtube.com/watch?v=DEKC5pyOKFU
     
  17. Re: Depth of Field in Macro Photography

    PERFECTLY illustrated, thankyou :good:
     
  18. efuller

    efuller MVP

    Aside from lighting another key factor is distance from focal plane to object. The farther you are from the object the smaller the image of the object will be. I've seen some camera manufacturers recomend using a string attached to the camera to get the correct distance. Nearly impossible to use the string when holding the camera in your hand, but a tripod would make it very easy. If you keep the light in the same place relative to the tripod you should be much more consistant. It's not necessarily practice, but doing the same thing every time once you figure out how to get a good picture.

    A good way to compare the lighting position is to look at the two pictures in this thread. They both have their uses. There is a program that is available to download that can measure the area within an image. I've never used it, but I would imagine that uniform lighting would help it work better. From looking at the two pictures, I'd say you get more uniform lighting when the light is from behind the camera. Photography is a lot like life, you will get better at it if you understand how you made your mistakes and don't repeat them.

    Eric
     
  19. If the light is behind the camera the lighting will more uniform but the skin ridges will be less distinct. If the light is at an oblique angle to the camera, the lighting will be sligthtly less uniform but the skin ridges will have more contrast and be, therefore, more distinct.

    I suggest you experiment with the camera perched on a tripod, camera in macro mode and then vary the light source with a few different angles to the foot to see which produces the image. My bet is that having the beam from the light source at about a 30 degree angle to the plane of the surface of the foot which you are photographing will produce the best image (see illustration).
     
  20. Thanks ALL for the time you've taken, and Kevin - love your diagram! I'm continually experimenting now with various subtle alterations, now I've been given an idea of where to start :)
    I'll keep practicing.....
     
  21. alessandro costa

    alessandro costa Active Member

    thank you kevin now we have your thumb skin lines...
     
  22. brekin

    brekin Active Member

    I use Photoshop to measure the area of the ulceration and then track that on an Excel graph. Extremely quick and easy, so long as you have a ruler for reference in the photo.

    Not all versions of Photoshop have the measurement tools available. I'm using Photoshop CS3 Extended edition.

    Cheers
    Brett
     
  23. 4d-imaging

    4d-imaging Welcome New Poster

    Last edited by a moderator: Sep 11, 2012
  24. Jose Antonio Teatino

    Jose Antonio Teatino Well-Known Member

    Mrs. Brightside:
    One more idea:
    When shooting a foot, put a colored construction paper, just behind the foot.
    It will be easier for autofocus to work properly, and besides most beautiful result, avoids distracting the photograph you see the vision of distant objects that contribute nothing to the main topic of interest photographed.
    I send you a photo of a phase-out of the nail plate as an example.
    Besides lka digital camera, I have a digital microscope to 200 X softward available to an injury to measure length and area, sending the images directly to your computer and very good to document the history and explain details to your patient.
    Very easy to use and very useful.
    greetings:
     

    Attached Files:

  25. Jose:

    Nice tip!:drinks
     
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