09-21-2018 02:47 PM
Take a look at extension tubes. An extension tube will extend your lens away from the sensor and turn your lens into a magnifying glass (you won't be able to focus on far away objects). It will also keep communication between your lens and camera, so you can auto-focus and adjust f-stops. The quality is very good depending on the lens you use it with. They are VERY affordable. I got mine for around $30. I don’t know if Canon makes extension tubes though. I would NOT recommend the lens reversing technique. It’s too difficult to use.
09-21-2018 03:18 PM
There are a number of ways to do "close up" photography and reversing the lens is just one method.
The "close up" diopters that attach to the filter threads are another option. There are two versions of these... Canon's and "everybody else's". Here's why.
The diopter is sort of like a person with poor eyesight wearing reading glasses... it allows the lens to come to focus at much closer distances than would normally be possible. The "cheap" versions of these are just a single lens element. But this creates a problem.
Since it's just a single piece of curved glass, that curvature acts like a prism. Light passing through the center focuses reasonably well. But near the edges you notice things starting to fall apart (a loss in image quality). Some people don't care about the quality near the edges so this solution may be fine.
Canon, on the other hand, have a special (actually two models) of close-up diopters that are TWO elements instead of one. The first element is the close-up diopter, and the 2nd element corrects for the chromatic aberration caused by the first element (it's basically an "achromatic doublet" arrangement). This gives the Canon version better quality results.
They make two versions... a 250D and a 500D version (and these come in different diameters). The 250D is for lenses that have a focal length in the 30-135mm range. The 500D is for lenses that have focal lengths of 70mm or above (e.g. a 70-300mm lens but you could use it on a 55-250mm lens if you use the "long" end of the focal length range). They are made in 52mm and 58mm thread diameters (both the 250D and 500D) and the 500D also is available in 72mm and 77mm diameter.
Extension tubes are another relatively low-cost alternative. These are simply hollow lens barrels with no glass. You attach the extension tube to the camera body and the lens attaches to the extension tube. Their purpose is to position the lens farther away from the sensor. By doing this, the range of focus distances is shifted closer to the camera. This means the minimum focus distance possible is now much closer than without the extension tube. But also the maximum focus distance is no longer "infinity".
Extension tubes also come in sizes... Canon makes one that positions the lens 12mm farther, and another model positions the lens 25mm farther. The Canon tubes do pass through all electronic communication (your camera still has control of the lens). The extension tube does impact the metering system, but since the Canon cameras knows how to detect a Canon extension tube, it will compensate accordingly and you'll still get correct exposures.
Kenko is also a popular maker of extension tubes.
As there is no "glass" in an extension tube, the image quality isn't an issue. The only quality issue is if the camera detects the extension tube correctly and passes through lens communications.
This is the ultimate solution ... highest quality and full control. A "true" macro lens will provided 1:1 image scale. That means the size of the object as it is projected onto the sensor inside the camera is as large as the object in real life. A US penny has a diameter of 19mm. The sensor on an APS-C camera is 22.5mm x 15mm. This means you can get so close to the coin that the top & bottom are cropped out and the left & and right edges barely fit in the frame (that's pretty close).
Most "zoom" lenses that have a "macro" range really only let you get to about 1:3 or 1:4 scale (not nearly as close as a true macro lens).
You can still use extension tubes or close-up diopters in conjunction with a true macro lens ... just in case 1:1 scale isn't close enough.
Canon does make one special purpose lens called the MP-E 65mm. This lens is a manual focus (EF & EF-S lenses are "Electro-Focus") but it allows focus to be achieved anywhere from 1x to 5x scale (5:1) ... so this is an EXTREME close-up lens. But it is intended for dedicated use as a macro lens.
While we're on the topic of macro... you might also want to think about lighting. Depth of field gets VERY thin at these extremely close focusing distances.
Here's an example:
Notice here how the depth of field is barely over 1mm thick (this was shot using a 100mm macro lens). This means that you're likely to stop down to a much higher f-stop to get everything in focus. But THAT means collecting less light through a tiny aperture and THAT means you may need a longer exposure time. This can be a problem if your subject is an insect (which tends to not sit still) or even a flower outside if the wind is gently blowing.
A solution is to use flash, but the on-camera flash can cast a shadow and a shoe-mounted flash can be too high that you get poor lighting.
There are special flashes designed to solve this problem. They mount to the front of the lens and one type has two flash heads (one left and one right). Another alternative is the "ring" type flash (the flash tube wraps around the lens).
This allows you to use faster shutter speeds and still get good lighting.
I don't advocate that you just run right out and buy one... I'm really just throwing this out there to give you an awareness that you might run into this problem ... but it's a well-understood problem that has already been solved.
09-21-2018 04:06 PM
There is also a concept called focus stacking. You take a bunch of images varying the focus point of each one. Special software then "stacks" the images, using only the sharp bits. Some cameras, though few canons, can do this automagically.
09-21-2018 05:25 PM
Thanks, guys. I bit the bullet this morning and bought a used Canon EF-S 60mm lens. It appears to be in excellent condition but until it arrives and I try it, I won;t know for sure.
I had read and looked at the extension tubes and close-up diopters and was thinking along those lines before posting this topic. It would have been good to experience those but since it may have ultimately led to the purchase of a macro lens, I am saving some time and money.
On the lighting issue, I will see how that goes. As you suggest, Tim, it is likely to be one of the many things that I need to learn to deal with when I start getting more into close-up photography. At this stage, it is all very new to me and yet to be even started.
09-21-2018 06:17 PM
I did not originally use a macro light and just relied on available light. If the subject isn’t moving then you can use a tripod and often not worry too much about the light (macro photography is commonly done on tripods).
On the topic of focus stacking, you can get a gadget called a focus “rail” that attaches to the tripod head. It’s a rail with a fine-adjustment knob that lets you move the camera forward or backward along the rail by a tiny amount at a time ... to guarantee that the camera is in the same horizontal and vertical position and the only thing that changes is distance. They aren’t very expensive.
An alternative is to wrap a piece of painters tape around the focus ring. Focus to the “near” distance of your subject and mark that on the tape. Focus to the “far” distance of your subject and also mark that spot on the tape. Now take a photo and gently nudge the focus ring, take another, adjust focus, take another, repeating until you reach the other mark on the tape.
The cautionary side of changing actual focus is that some lenses “breathe” which means that the true focal length changes as you adjust focus. But most focus stacking software is able to match up the frames well enough to get a good result.
09-22-2018 10:14 AM
"I had read and looked at the extension tubes and close-up diopters and was thinking along those lines before posting this topic."
You are much better off with the 60mil macro. Makes your life a lot easier.
09-22-2018 01:01 PM
“I had read and looked at the extension tubes and close-up diopters and was thinking along those lines before posting this topic. It would have been good to experience those but since it may have ultimately led to the purchase of a macro lens, I am saving some time and money.”
I would avoid close-up diopters, or anything that introduces lens elements to the light path before it hits the image sensor. Most of the inexpensive ones degrade the images more than they are worth. The lens reversing adapters are the worst option of them all.
There is nothing really wrong with extension tubes because they do not introduce lens elements. Extension tubes come in two flavors, passive and active. Basically, some have lens contacts so that you can still auto focus. The really inexpensive ones do not have contacts, so you will lose auto focus and more importantly you will lose aperture control with most lenses.
The downside to extension tubes is that you lose the ability to focus at a distance, like just across the room in some cases. But, if you are shooting at closeup subjects, then not being able to focus at a distance becomes irrelevant.
Extension tubes can be stacked, which creates an effectively longer extension. The tubes have sizes. Basically, you want to use an extension tube size that is 25% of the focal length of the lens that you plan to use.
The best solution is to get your hands on the already mentioned EF-S 60mm f/2.8 Macro lens.
09-22-2018 02:47 PM
The best solution is to get your hands on the already mentioned EF-S 60mm f/2.8 Macro lens.
Hi, thanks for that. I did buy a used 60mm lens and it arrived today. I have had a look at it and it looks it really good condition. I have only taken a couple of very quick photos with it to test it as it is now going away for a week until I get it given back to me as an anniversary gift!!! It also incuded a lens hood which I was not expecting.
09-22-2018 09:20 PM
"I did buy a used 60mm lens and it arrived today. "
You know you can use it for more than just a macro. It is a pretty good general use lens.