G11 macro lens needed by dentist

[doctorpaul]

Hi all, i bought the g11, to take pictures at work, and its nearly good enough for the close ups (say five or six inches wide)

when i shoot, i have a patient in the chair, usually lying down, with some natural light, plus our overhead fluorescent lights.

As for the settings, i have everything on auto, as i have mucked around with things but auto seems to work well for me

I need to have the digital zoom to 2.3

If i do all this, i get a pretty good shot, but not perfect.

Two questions. Is it worthwhile buying a macro lens, to do the job properly?

Secondly, is it possible to set the digital zoom higher than 2.3. I know it will go higher, as the zoom goes to X20, which i assume is 5X lens and 4X digital. I know i would have some image deterioration, but dont think that would be a problem. Perhaps if i could set the digital zoom to 3 or 3.5 i would be happy.

Any thoughts? This noob appreciates all help!

[StuM]

Hi Doc,

A silly question to start with....but.....you are using the camera's macro function?

Using this you should be able to get within an inch or two of your patients front teeth without using any zoom.

I cant really see any advantage using digital zoom.....you might as well just blow up your 5x optical shots.

[doctorpaul]

Yes, i am using the macro function

There are two issues.

YEs, i can get REALLY close and get a good pic, but then the natural light is in the way, and the flash is in peoples eyes.

It is also too close and is in my patients personal space (kindof ironic coming from a dentist!)

[denncald]

It sounds like you need a macro lens (filter). Something like a Hoya Macro set (+1, +2,+4) would give you options to move back from your patient, and maybe make use of one of those blazing bright dental lamps I'm always blinded by.You could not use the built-in flash, since the tube blocks most of the flash. I use off-camera flash for macro, which you could do with a 220EX/270EX flash and an off camera shoe cord. I would not recommend the Canon cord, since it is short and difficult to maneuver. You would need either the Canon adapter tube for the G10/G11 designed to attach a tele conversion lens, but also allows you to attach a 58mm filter like the macro ones. Or, get parts A and C tubes from Lensmate designed for the same purpose but costing more, because they are precision tooled metal vs plastic Canon.

Dennis

[John Baker]

Hi DoctorPaul, macro is one of my great interests. As pointed out the issue you have is there is a great macro facility built into the camera, however you can only really access it at the widest setting. You basically have two problems you are looking to solve one getting the light in the right place and the second is getting a better working distance.

Lighting is quite easy, while Off camera flash would work, either via cable or wireless, it would be directional, which is great for modeling, but possibly not really the effect you are after! I think what you really need is a dedicated ring flash, either the cheaper Canon unit MR14 (which is still expensive) or possibly one of the cheaper other makes, look at either the Sigma MACRO EM-140 DG or Marumi DRF14C both products will fit the bill for you. There are also a number of LED based units coming on the market which may also do the job?

Long macro – there have been several discussions on here, and as Dennis points out above, you basically need a Canon LA-DC58K extension tubes, or the Lensmate or one of eBay clone versions. This will then allow you to fit a supplementary, close up lens to the front of the camera. CL basically come in various strength, while the Hoya are quite good, they are single element, the better ones if you can find them are the achromatic, or double element versions. What these will allow you to do is to use the macro facility at the longest zoom of the camera. A +4 should allow you get about 20cm from the subject and give a good view of a couple of teeth, you may need a lower power to get the whole smile – for more information on Close Up lenses could I suggest you have a look at - http://freenet-homepage.de/seemolf/achromats.html - which should cover most of your, knowledge needs.

[tware]

G10 (same optics), 500D (500mm fixed focal length, probably the highest quality glass you will find for this), hand held, no extra lighting.

over 12 inches away, no crop, only resized for posting here
http://www.timware.org/camera/500d-1.jpg

http://www.timware.org/camera/500d-1b.jpg

13-14 inches away with digital zoom
http://www.timware.org/camera/500d-2.jpg

now with max d.zoom
http://www.timware.org/camera/500d-3.jpg
now thats handheld after 3 cups of coffee, over a foot away. the quality is degraded (due to the digital zoom, not so much the glass), but the image is still quite usable.

I'm sorta done playing with it. I got it for the G10 and XSi, but honestly, I'm ready to play with a 100mm Macro on the XSi. :) So to fund that, I will consider selling the tube and 500D.
http://www.timware.org/camera/500d-4.jpg

I have made some macro lights from small camping LED ring lights. They are small, but somewhat janky to use in a professional setting. I would consider a camcorder light (constant on) since you have tons of lighting already and youre trying to eliminate shadows. Plus, it wouldnt blind you patients (so much).

[tware]

oh, and yes, with the opteka in this configuration (58mm), there is vignetting when shooting at the widest focal length. I dont know the exact point at which it is overcome, but doesn't take much, still shoots fairly wide. It's a nice balance, the 500D in 72mm was much more expensive and dwarfs the G10. It also blocks the AF assist beam. This does not. those were all AF shots.

[denncald]

tware,

thanks for the shots. I have the G9 (still) and am considering either the 500D or 250D, or both. I'm curious why you decided on the 500D for the G10 vs the 250D.

thanks,
Dennis

[tware]

I tried both with similar results (great), but the 500D on my 55-250mm XSi lens and longer focal lengths of the G10 simply gave me more working distance. Easier to not scare away critters with macro. The 250D is suited for under 100mm, the 500D is suited for something like 130mm and up (I dont recall exactly, but the charts are all over the web on these).

But the G10 is easier to maneuver than the XSi + 55-250mm. So, it ended up not being much of a necessity, it's usually pretty easy to get in closer with the G10.

[denncald]

doctorpaul,

This ring light was posted on another thread, in case you did not see it.

http://www.newworldvideodirect.com/productdetail.asp?productid=19792

Dennis

[John Baker]

Both the Canon 500D and 250D are achromatic filters, in that they have high quality, double elements and are corrected to bring two wavelengths (typically red and blue) into focus in the same plane and designed to limit the effects of both chromatic and spherical aberration. The 500D is a +2 dioptre lens, so when placed either in front of the main lens, or behind a converter the camera will focus at 500mm (e.g. 1m divided by 2 = ½ metre or 500mm), the 250D is a +4 dioptre and will focus at 250mm (e.g. 1m divided by 4 = 1/4m or 250mm) – technically the 500D is optimized for lenses from 70-300mm and the 250D is for 50-135mm. There are a whole heap of other versions around from the very expensive Leica Elpros, through to the relatively lower cost Nikon T series, the Canon versions are considered to be in the mid price range. A very popular brand is Raynox, they make a number of version of achromats, the DCR-150 is a +4.8 dioptre (min focus 210mm) and the DCR-250 is a +8 (min focus 125mm), I believe they also do a +10 and a +20 monster(?), if you want to go that close! Remember you can also double these up, so if you had 2 x 250D’s you could join them up and that would give you the +8 dioptres, or you could have both a 500 and a 250 which would give you +6 - it is all simple really!!!

I have just purchased a Raynox 2020Pro, which is a 2.2 converter which will basically make my G11 into a 300mm beast, I am going to be trying various combinations of achromats to see how they work with this combination, because the same rules as outlined above will apply – it should be with me tomorrow!!! I will post some results once I have the kit.

I have managed to pick up a number of older, very high quality achromats for next to nothing on eBay, they range in size from 49mm through to 58mm. Possibly the best I have is an old Konica/Minolta CL49-200 which is labelled +4 but is actually closer to +5, in use it is a 49mm filter, which is attached with a couple of step down rings, 58-55 and a 55-49 without any loss of quality or vignetting problems at 140mm on the G11.

You may have to experiment, some of these options will fill your frame with a single tooth cusp! A simple, cheap set of single lens element Hoya’s +1 +2 +3 and +4 (as suggested by Dennis) would be a great place to start, once you know what combination (magnification) is best for you and you can see what the results are like, you may actually find they are good enough – do you really need to see every minute fissure, only you can answer that one!

A couple of interesting links for those who want more detail on achromatic filters

http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/A95/Close-Up/Close-Up-Lenses.html
http://fuzzcraft.com/achromats.html
http://freenet-homepage.de/seemolf/achromats.html

[LowriderS10]

why not buy a used Rebel XT/XTi and throw a real macro lens on it?

also, turn the digital zoom off. It does absolutely nothing. What it does is the equivalent of you zooming in on your computer screen.

[John Baker]

why not buy a used Rebel XT/XTi and throw a real macro lens on it?

also, turn the digital zoom off. It does absolutely nothing. What it does is the equivalent of you zooming in on your computer screen.

Because a DSLR has a very narrow band of focus with a macro lens, so at higher magnifications you can be talking mm's which is a real problem. You can get around it by techniques such as photo-stacking, where you combine multiple images. Whereas a small sensor camera will give you far great DoF without any of the problems...

http://www.jfbclick.com/images/10-03KillBugs/IMG_1451.jpg

This is possibly a better shot and shows the extended DoF
http://www.jfbclick.com/images/10-G11-Watches/Pair-800.jpg

[LowriderS10]

Ah thanks...good point, however, I don't really consider either of those shots true macros...in a true macro (to me, at least) in the first pic, for example, you'd barely be able to see more than the bee...

[John Baker]

Ah thanks...good point, however, I don't really consider either of those shots true macros...in a true macro (to me, at least) in the first pic, for example, you'd barely be able to see more than the bee...
I can see your point, I was trying to keep the magnification down - here are a couple more examples to show some bigger enlargements. It is still very early in the season in the UK and the weather is only just starting to warm up, so we are only just beginning to get the bugs now!

Here is my watch with two achromatic fitted a +4 and a +1 so equivalent of +5
http://www.jfbclick.com/images/10-CloseTest-G11/Tcon-Plus-5-Dio.jpg

Possibly not big enough for you, to go really large you can always fit a reversed 50mm on the camera - that gets you to about +20
http://www.jfbclick.com/images/10-CloseTest-G11/Rev-50mm-3.jpg

or how about a dragonfly exuvia
http://www.jfbclick.com/images/10-CloseTest-G11/Exuvia-2.jpg

Kit looks like this - since doing my first test I have found that you do not need both adapter tubes, as the front of the lens is deeply recessed.
http://www.jfbclick.com/images/10-CloseTest-G11/G11-plus-50mm.jpg

[LowriderS10]

that looks badass!!! And the results look great! :)

[tware]

Oh man.. I was seriously thinking of selling my G10 today (and opteka tube + close up lens)... I shoot all the time with a rev 50 on my XSi and never considered trying that on the G10... and that the opteka could be used as an extension tube! Brilliant.. seriously. Guess I'll be putting off those FS listings for awhile while I mess with that.

[IVOlution]

John...THANK YOU!
this is great info.
:)

[MizeDentist]

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