Monday, April 20, 2009

I Need help understanding Macro Lens for digital photography pictures of teeth, what to buy.?

At our dental office we are just starting to look for a digital camera to take very close pictures of teeth. The problem is we are all amatures at photography or digital cameras. I said we need a macro lens to do this. Some else said we need zoom capability, I don%26#039;t think that is right.





I suggested we need a digital SLR like a nikon rebel, of course with a flash too. Does it need to be a %26quot;ring%26quot; flash?





I know nikon rebels are $800 and up, and the macro lens would be a separate expense too, right?





Some else at the office was hoping we could do this with a much cheaper camera, I said %26quot;in your dreams%26quot;!





Please advise...

I Need help understanding Macro Lens for digital photography pictures of teeth, what to buy.?
To get really clear and detailed images of teeth you will need a lens which has the ability to focus at short distances. That would be a close-up or macro lens. The addition of a ring light would be to provide equal lighting from all angles, thus reducing any shadows and providing the greatest possible detail.





Additionally, because you are going to be working at close range it is imperative that you be using a single lens reflex camera, where the viewfinder actually looks through the lens.





I would recommend a Cannon EOS Rebel XSi with a EF-S 60mm f/2.8 Macro USM Lens and a Macro Ring Lite MR-14EX.
Reply:I shoot for some dentists in my area. I use a Nikon D200 and a 105mm macro VR lens with a %26quot;macro%26quot; flash unit (like you see on CSI from time to time). It is the Nikon R1C1 package





Too purchase something like this will cost about $1800 for the D300 (replaces the D200), $760 for the lens and $680 for the macro flash. Not a lot when you compare it to other tools the dentist uses in his/her practice. Less than $3500 when you include a good tripod and tax.





Your dentist should have some experience using something like this from dentistry school.
Reply:As far as macro lenses go, you could do a lot worse than a Sigma 105mm macro lens which would give you 1:1 or lifesize macro.





Your question %26#039;Does it need to be ringflash?%26#039; Yes, it does. The guide number of the ringflash is best suited to macro photography. If you were to use normal flash guns, you would need to adjust the light output down to around 1/4 to 1/8th of the flash%26#039;s power to avoid a %26#039;whiteout%26#039;, whereas, the ringflash takes care of that already.





Sigma makes this lens in a variety of fittings including Canon, and you will find it quite capable of the kind of shots you%26#039;re after.


As for ring flash, one of the best on the market is also made by Sigma (no, I don%26#039;t work for Sigma) which will give you the necessary flash power to do macro photography, without spending a small fortune.





It matters not what camera you use, it%26#039;s the quality of the lens that really counts. Even if you used a bottom of the range Canon digital SLR, the quality of the optics is what will ultimately make the difference. Your patients will thank you for making a considered professional choice, especially if a good colour match is part of the desired result in the case of veneers or crowns etc.





Many years ago, Polaroid developed a specialist camera for the dental profession. In the UK Yellow pages, Dental surgeons comes after Demolition.





Check out the links for more.
Reply:Go with photoace -- he%26#039;s a real expert here. I would just add that you cannot compromise on the lens -- the 105 macro and suggested flash would be perfect. However, you don%26#039;t need the super-robustness or the rapid burst features of the D300; you could get equally satisfactory results with the D80 and save $1K.





Oh, and you%26#039;re right: zoom does not replace macro. Just because you can zoom a lens and make things appear closer does NOT mean that lens will focus really close -- that is the function of a macro lens.
Reply:Visit the Lester Dine site - lesterdine.com. They are specialists in the type of photography you need to do in the dental office.
Reply:Ok, I%26#039;ll comment on the different components and you can decide what to do.





In terms of the camera, you%26#039;re right, you need an SLR so that you can see in the view finder exactly what your image is going to look like. Now, the Canon Rebel won%26#039;t work for you, it doesn%26#039;t have a spot meter, something that%26#039;s crucial for macro work. You%26#039;d have to select a higher Canon model or select a Nikon. Any model of Nikon will work. If you want to go on the cheap you can use the D40x, it%26#039;s an excellent entry SLR that takes exceptional pictures. If you want some more control and options, something I don%26#039;t think is necessary in this case, go for the D80. I personally use a Nikon D200 and I love it, but then I don%26#039;t photograph teeth, I%26#039;m into bugs and fungus both of which can be a real challenge and is certainly far more challenging than teeth. So I need the additional features of the D200. Were I do do only teeth I%26#039;d be happy with the D40x.





You don%26#039;t have to buy an SLR with the kit lens that%26#039;s offered. You can buy it with any lens you want and usually that will get you a bit of a discount on the lens when you buy it with the camera which will save you a bit of money.





So what lens? Clearly you have to use a macro lens and preferably one that goes 1:1, basically life size. NIkon has two flavours of this, a 60mm and a 105mm. There are others that offer %26quot;macro%26quot; capability but they are not true macros and will give you only a 1:2 ratio (half life size). A macro lens also focusses on a flat plane instead of the more usual curved plane which is crucial in macro work. A lot of lenses call themselves macro because they allow you to get closer to your subject, but that doesn%26#039;t make them true macros and they won%26#039;t get you the outstanding images you need.





With macro photography, the lens to subject distance is determined by the size of the subject and the focal length of the lens. If you%26#039;re photographing a filling in a tooth, using the short lens, the 60 mm, means you really have to get close (porbably a very few inches), which can be a problem with the patient. A longer focal length is really needed for your application. Using the 105mm instead allows you at least a foot of lens to subject distance which is easier to handle both for yourself and for your patient. Additionally, the 105mm lens has an excellent image stabilizor that takes case of any camera shake. So in this case I%26#039;d recommend the 105mm lens. I have both and they%26#039;re both excellent lenses, but the 105mm is the best for what you%26#039;re trying to do considering the constraints under which you%26#039;re working.





Finally, in terms of illumination, yes I agree a ring flash is ideal. You%26#039;re not trying to create art, you%26#039;re trying to capture clinical details so it%26#039;s essential that you have even illumination that eliminates all shadows.





Sigma has an excellent ring flash that works perfectly with the NIkons. It%26#039;s reasonably priced and with the 105mm macro gives you a comfortable working distance that won%26#039;t distress your patients.





Nikon does have a macro flash too which an earlier correspondent alludes to, but I personally feel it%26#039;s not practical for what you%26#039;re trying to do. Additionally it%26#039;s heavier, bulkier and requires more fussing to capture the image.





So, my suggestion is a Nikon D40x with a Nikon 105 mm macro lens and the Sigma ring flash. That would be the least expensive solution to your need. If you feel you need more sophistication camera wise, I%26#039;d select the D80 instead with the same lens and flash. Anything more would be over kill.





I hope this helps a little.



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