I've been shooting macro for 15 years, but have been bitten by the micro bug, and am looking for an entry path. The body I use is a 1D-X (full frame), and I also have a 1D-Mk 4 (1.3 crop factor). I already have a StackShot, and Zerene stacking software which I use in conjunction with my MP-E65 macro for magnification up to 5X, and even 7X using a 1.4x teleconverter (not convinced the TC helps).
My objective is to move into the 5X - 20X range of magnification.
For the mico setup, I'm leaning towards an infinity configuration, using one or more of the lenses I already have as the tube lens. They are the Canon EF 180/3.5 macro, EF 70-200/2.8 zoom, and EF 300/4.0 IS. The micro objective I have my eyes on is the 10X Mitutoyo Plan Apo Infinity-Corrected Long WD, stock No. 46-144.
My questions are:
1. I've read that macro lenses are not favored for infinity arrangements. Would this apply to the180/3.5 macro that I have? Can spacers aleviate any problems?
2. I favor prime lenses, but wonder if the 70/200/2.8 zoom would serve?
3. Same question for the 300/4.0 IS. I'd switch the IS off)?
4. Can the lens iris (aperture setting) be used to adjust exposure, or must the "tube" lens remain wide open?
5. Would the camera's exposure control in Manual mode operate normally on flash. I'd use test exposures, and adjust camera and flash settings accordingly via the camera?
6. Is magnification more or less fixed for a given objective - prime lens combination?
7. Am I correct that the 300/4 and 10X micro objective combo would get me to 15X?
8. Can extension tubes or bellows between the "tube lens" and camera body be used to increase magnification?
9. Is there another lens, objective or "tube" that would be better suited to my objectives.
Sorry for so many questions. Any help will be greatly appreciated.
Tam
Infinity Setup Starting With Existing Equipment
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rjlittlefield
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Re: Infinity Setup Starting With Existing Equipment
1. I've read that macro lenses are not favored for infinity arrangements. Would this apply to the180/3.5 macro that I have? Can spacers aleviate any problems?
A macro lens that focuses to infinity will work fine. At that focus setting it's just like any other 180 mm telephoto. As with all telephotos, there is some possibility of vignetting. But since this is a prime, there's a better chance it would work.
2. I favor prime lenses, but wonder if the 70/200/2.8 zoom would serve?
At its 200 mm setting, this would probably work OK on an APS-C sensor. With your larger sensors, it's likely that you'll get some vignetting.
3. Same question for the 300/4.0 IS. I'd switch the IS off)?
Yes, switch the IS off. This lens would probably work OK, bearing in mind that it will give 1.5 times the rated magnification of the objectives.
4. Can the lens iris (aperture setting) be used to adjust exposure, or must the "tube" lens remain wide open?
The lens iris definitely can not be used to adjust exposure. Some people find that image quality increases a little bit by stopping the lens iris to just before the point where vignetting kicks in.
5. Would the camera's exposure control in Manual mode operate normally on flash. I'd use test exposures, and adjust camera and flash settings accordingly via the camera?
Using the lenses you've mentioned, and forcing the iris to stay open, all of the camera's exposure controls will work as usual. The camera will have no idea that there's an objective added in front.
6. Is magnification more or less fixed for a given objective - prime lens combination?
Yes.
7. Am I correct that the 300/4 and 10X micro objective combo would get me to 15X?
Yes.
8. Can extension tubes or bellows between the "tube lens" and camera body be used to increase magnification?
Yes, up to a point. Microscope objectives are sensitive to being dragged away from their designed focus point. It gets worse at higher magnification and wider apertures. 10X NA 0.28 is not very sensitive; 50X NA 0.55 is much more so.
9. Is there another lens, objective or "tube" that would be better suited to my objectives.
You might consider the Raynox DCR-150. It behaves remarkably well even on full frame, sharp and no vignetting, and it's cheap. See http://www.photomacrography.net/forum/v ... hp?t=23898.
--Rik
A macro lens that focuses to infinity will work fine. At that focus setting it's just like any other 180 mm telephoto. As with all telephotos, there is some possibility of vignetting. But since this is a prime, there's a better chance it would work.
2. I favor prime lenses, but wonder if the 70/200/2.8 zoom would serve?
At its 200 mm setting, this would probably work OK on an APS-C sensor. With your larger sensors, it's likely that you'll get some vignetting.
3. Same question for the 300/4.0 IS. I'd switch the IS off)?
Yes, switch the IS off. This lens would probably work OK, bearing in mind that it will give 1.5 times the rated magnification of the objectives.
4. Can the lens iris (aperture setting) be used to adjust exposure, or must the "tube" lens remain wide open?
The lens iris definitely can not be used to adjust exposure. Some people find that image quality increases a little bit by stopping the lens iris to just before the point where vignetting kicks in.
5. Would the camera's exposure control in Manual mode operate normally on flash. I'd use test exposures, and adjust camera and flash settings accordingly via the camera?
Using the lenses you've mentioned, and forcing the iris to stay open, all of the camera's exposure controls will work as usual. The camera will have no idea that there's an objective added in front.
6. Is magnification more or less fixed for a given objective - prime lens combination?
Yes.
7. Am I correct that the 300/4 and 10X micro objective combo would get me to 15X?
Yes.
8. Can extension tubes or bellows between the "tube lens" and camera body be used to increase magnification?
Yes, up to a point. Microscope objectives are sensitive to being dragged away from their designed focus point. It gets worse at higher magnification and wider apertures. 10X NA 0.28 is not very sensitive; 50X NA 0.55 is much more so.
9. Is there another lens, objective or "tube" that would be better suited to my objectives.
You might consider the Raynox DCR-150. It behaves remarkably well even on full frame, sharp and no vignetting, and it's cheap. See http://www.photomacrography.net/forum/v ... hp?t=23898.
--Rik
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rjlittlefield
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It's been pointed out to me offline that my answer to question 8 may not be well targeted for a reader who is experienced in macro but new to microscope objectives.
In traditional macro, it is standard practice to gain magnification by adding extension.
But when using microscope objectives, adding extension is not standard practice.
Instead, the usual path to higher magnification is to buy another objective, for example 20X NA 0.42 instead of 10X NA 0.28. This method increases both magnification and resolution on subject.
Alternatively, if modest amounts of additional magnification are required from a particular infinity objective, then the standard approach is to use a longer tube lens or to stick a teleconverter on the camera. Both of those approaches allow the tube lens to remain focused at infinity as the objective expects, and in its normal relationship to the camera as the tube lens expects. If you're looking for well worn paths, those are the way to go.
Note that increasing magnification while using the same objective typically does not increase resolution on subject, because the resolution is limited by diffraction in both cases. The value of increased magnification is mainly to use a larger sensor area, giving an image with less pixel noise.
I hope this clarification helps.
--Rik
In traditional macro, it is standard practice to gain magnification by adding extension.
But when using microscope objectives, adding extension is not standard practice.
Instead, the usual path to higher magnification is to buy another objective, for example 20X NA 0.42 instead of 10X NA 0.28. This method increases both magnification and resolution on subject.
Alternatively, if modest amounts of additional magnification are required from a particular infinity objective, then the standard approach is to use a longer tube lens or to stick a teleconverter on the camera. Both of those approaches allow the tube lens to remain focused at infinity as the objective expects, and in its normal relationship to the camera as the tube lens expects. If you're looking for well worn paths, those are the way to go.
Note that increasing magnification while using the same objective typically does not increase resolution on subject, because the resolution is limited by diffraction in both cases. The value of increased magnification is mainly to use a larger sensor area, giving an image with less pixel noise.
I hope this clarification helps.
--Rik