Focus on Macro. (Part 1)

Over the past few days, I got some great responses to my bugs. Thanks guys! I am going to write a series about the gear I use and some basic techniques. I am not an optical engineer so my explanations are going to be from a working perspective.

I will be talking in terms of 35mm DSLR systems (almost all of this translates to 35mm film also). But, compact digital cameras have the ability to do macro photos quite well. Due to their tiny image sensors and small lens combinations you can focus very close with most point-&-shoots. Their limitations in speed, high ISO performance, and lens selection however make them unsuitable for my needs.

Ok, so there are a bunch of ways to get close to your subject: macro lenses, macro filters (close-up filters), extension tubes, bellows extensions, tele-converters, telephoto zoom lenses, stacking reversed lenses, and microscope adapters. All of them do a good job making little things look big. As far as their effectiveness goes, that depends on what you are trying to photograph and where you are trying to do it.

The most simple yet effective, all around, solution is a macro or close-up filter. Just about everyone who makes filters (Hoya, Tiffen, B+W, etc.) has a close-up filter solution. HOWEVER, not all close-up filters are created equal.

A little background info for those who are not familiar with close-up filters. They are exactly as named: a filter that lets you focus close-up. You take one of these and screw it onto the front of your lens and it reduces the closest focusing distance. These filters will have different powers of magnification and you can stack them to multiply their effect.

Getting back to filter quality, even the cheapest kit lens for a DSLR has special anti-reflective (AR) coatings on the lens elements to improve image quality. Most thread-on filters are NOT given an AR coating–including most close-up filters. Why is this important? For anyone who wears glasses, you know immediately what I am talking about. Reflection and glare are huge problems for any piece of optical glass or plastic. No matter what lens you are using (expensive or otherwise), if you take a cheap filter with no AR coating and put it in front of your lens–your lens has now been reduced to the optical quality of that filter. AND if you stack filters you also multiply the reduction in image quality.

So, who makes a high quality AR coated close-up filter? CANON does, that’s who! I am talking about the 250D and 500D series of close-up filters. Both filters are composed of top quality Canon glass and they are anti-reflection multi-coated! As far as macro filters are concerned, it doesn’t get any better than that *period*

The 250D is recommended for use on lenses with focal lengths of 30mm to 135mm. The 500D is recommended for use on lenses with focal lengths from 70mm to 300mm. I own a 500D and have used it on all of my lenses–works just fine, even on my wide lenses–get the 500D. The 500D basically cuts your closest focusing distance in half. You will not be able to focus at infinity, with the filter attached, but who cares? You are using the filter to focus close-up! Canon made these filters primarily for their lens line up and it shows by the limited filter diameters.

If you own more than one lens, chances are good that your filter diameters are not all the same. That is a problem easily solved. What is the largest diameter lens you own? Buy the filter that fits that lens perfectly. Then purchase step-up ring adapters for each lens that has a smaller diameter filter thread. Step-up rings are cheap–you can find them on ebay for 3 bucks each. If you have one lens or only want to use the filter on one lens–no problem to begin with.

My primary use of the 500D has been on my 70-200mm f/2.8 VR. Zoom lenses with VR or IS are really helpful! I shoot most of my macros hand-held, only because most insects and reptiles will not wait around for you to set up a tripod. (The ideal situation is to use a tripod–I always get my sharpest images on a tripod.) But VR works, even when shooting macros, I don’t care what the haters say. I have gotten more keeper shots with VR–simple as that. Most of my images in the “Bugz” gallery were made with the 70-200 and a 500D.

I sometimes use a tele-converter along with my 70-200 and 500D combo. Here is why: the 70-200 f/2.8 has a closest focusing distance (CFD) of 4.9 feet. Adding a 2x TC gives me a 140-400 f/5.6 with a CFD of 4.9 feet. The TC does not change your CFD–it stays the same–a great thing! (Your maximum aperture suffers but I will get into that in part two of this series.) With the TC alone I can get much closer to my subject by simply turning my zoom ring. You see where this is going? Now by adding the 500D filter to the lens + TC combo my CFD is cut in half: 2.45 feet. Imagine that, a 400mm f/5.6 that focuses at 2.45 feet! We are talking some serious magnification @ a very comfortable working distance!!

So what is the difference between closest focusing distance and working distance? CFD refers to the distance from your subject to your sensor (film) plane. If you look at the top of any film SLR and any quality DSLR you will see a marking that looks like the Greek “phi”–a circle with a line bisecting it. That mark tells you where your sensor plane is. You measure your CFD using that mark to your subject. Working distance refers to the distance from your subject to the front of your lens. You calculate your working distance by subtracting the distance of your (sensor plane to the front of the lens) – (from your CFD). My smallest working distance (greatest magnification) is about 1.5 feet (with above mentioned set up). That is the limit of comfort for Phelsuma laticauda (Gold Dust Day Gecko)–my favorite macro subject. I found that I can usually approach them up to about 1.5 feet before they bolt. Nice how that works out, isn’t it? ;-)

A telephoto VR zoom, tele-converter, and Canon 500D close-up filter are–by far–the most versatile shooting system I use. With those three things (and a good camera body) I can shoot sunrise to sunset and be completely satisfied. I can cover macro, super tele, and medium tele subjects with just those three pieces of equipment. However, you know what they say about the “Jack-of-all-trades”…I’ll be covering that in part two. Please stay tuned. :-)