Tag Archives: Macro

Q&A: Third Party Macro Lenses?

(This post is from an email conversation with a coworker. I thought the content might be useful for others.)

Q:  Have you or anyone else used the Tamron 90mm f/2.8?  For $459 I’m wondering if it worth the price or if I should just stick with the known quality of Canon.  Have you compared the 100mm to the 100mm L for sharpness?

A:  I’m generally a snob about sticking with the Nikon (or Canon) lenses.  And even though the cost is sometimes double that of a 3P lens or more, there are two things that make the additional cost easier to swallow.  First, bodies come and go, but your lens investment will span decades.  I have a number of great Nikon lenses that I’ve had for 20+ years that work perfectly with my latest Nikon bodies (e.g., 300/4 AF, 180/2.8 AF, 85/1.8 AF).  Second, OEM lenses depreciate much less than 3P lenses do.  In fact, quite a few of my lenses are worth more now than I paid for them.  So a little depreciation spread over a lot of years makes for a very good overall cost proposal.

WRT 3P lenses, in nearly every case the 3P lenses produce visibly inferior images compared to their OEM counterparts.  And in most cases, the build quality and sealing is much poorer.  Finally, the resale value is much lower.

All that being said, the macro lenses, and specifically the 90-100mm range products are the one sweet spot for the 3P manufacturers.  Most of them are good, and the Tamron 90/2.8 specifically has always been an excellent lens throughout the many versions.  I’ve had two of them and at one point (back when I had time (= before kids)) I tested all of my lenses and the Tamron 90 was significantly sharper than every one of my excellent Nikon lenses.  (The Nikons did beat the Tamron for contrast, though.)

The Tamron build quality is decent, and it actually holds its value better than other 3P lenses.  One note of caution, though, is that the chips in the Tamrons sometimes are not compatible with new bodies (at least on the Nikon side), so you may not get the same life span out of them.  (That’s why I’ve had two of them instead of just one…)

And a final note on the original question, I haven’t used my 90mm Macro in probably two or three years.  First off, I don’t do that much closeup stuff.  And with many subjects you just have to get too close with a 90mm (even worse with a 50 or 60).  So when I noticed how well my 300/2.8 AFS with a 2x converter could do with small subjects from three or four feet away, I’ve been using that combo ever since.  I can take pictures of all sorts of cool bug stuff without disturbing the bugs or modifying their behavior in any way.

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Taking Photographs of LCD Monitors

Recently I needed to get some screen shots for a presentation. Normally I would just use the built-in screen grabber, but some of the images I needed were of startup screens during the boot process before the UI becomes available. So I figured I would just grab my camera and get on with it.

That was about the time I realized that it wasn’t quite as easy as I thought.

As far as absolute sharpness goes, my Tamron 90/2.8 Macro lens is as good as I have, so I put it on my D700 and set up for the shots. Here is what I got first at f/5.6, its sharpest aperture:

F5.6

D700, 90mm, ISO 200, F5.6, 1/50

Even after fiddling around with other lenses and different distances, I could not get around the interference pattern between the pixels on the screen and the sensor. So I started trying different things to reduce the sharpness.  First I opened the lens up:

F2.8

D700, 90mm, ISO 200, F2.8, 1/160

Plan B. Since the pattern appeared to be chromatic, I thought maybe getting rid of the color would solve the problem:

F5.6 BW

D700, 90mm, ISO 200, F5.6, 1/50

I was about to give up when I remembered two articles (here and here) I had read recently about the detrimental effects of using too small an aperture, and how that minimum aperture depended on the size of the photo sites on the sensor. It said that on a full frame sensor like the D700, the effect began to appear around f/16, but I tried the smallest aperture the lens offered, f/36.

F36

D700, 90mm, ISO 200, F36, 0.8s

Interference gone! But the image was very soft, and since I needed as much detail as possible for my presentation, I tried opening up to f/22 to regain some detail, but hopefully stay below the threshold.

F22

D700, 90mm, ISO 200, F22, 1/3

Better detail, but with noticeable moire. Next I tried f/32:

F32

D700, 90mm, ISO 200, F32, 0.6s

That gave the least detail loss without any visible interference. Finally!

So the solution was to leverage the reduction of sharpness due to diffraction. Not exactly what I expected when I began the project, but an adequate solution, nonetheless.

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