Quick and dirty 100mm test: Fujinon, Pentacon, Tamron

ludoo · Expire: 2011-12-05

This morning I had some free time, and decided to do a quick test of my 100/105mm lenses: the non-EBC Fujinon 100mm 2.8, the Pentacon 100mm 2.8, and the Tamron 105mm 2.5 I posted about a few days ago. I might have added the Hoya HMC 80-205mm 3.8 which I love, but only thought about it later, maybe next time.

For testing, I mounted the camera on my tripod, used hoods on all the lenses (the Fuji metal hood for the 100mm on both the Fujinon and Pentacon, and a slightly shorter unnamed metal hood on the Tamron), and shot a series of pictures at maximum aperture and f5.6 from about 2.5m. I set a fixed wb on sunny so as not to have color differences due to wb, and waited to shoot until the light was about the same (the sun was partly clouded from time to time).

An interesting thing to note is that the Fujinon has a front lens with lots of tiny and a few larger scratches, it's a lens most of us would pass, or only buy for a cheap price: looking at the actual pics, it does not seem to make any difference. All pictures were shot in raw on my *istD, and converted to jpg with Pentax Photo Lab with default settings. Scaled pictures were resized with convert (imagemagick) with no sharpening. I have assembled the pictures in strips using crops from the original images (originals here) so as to make it easier to compare them, all the pictures have the three lenses in alphabetical order: Fujinon, Pentacon, Tamron.

Ok, on with the pictures. First of all, the lens themselves

Next, the f2.8 shots, with the Tamron at f2.5

The Fujinon and Pentacon look remarkably similar, and this is something that you'll see in all the photos, with the Fujinon having slightly warmer colors and the Pentacon slightly cooler. A weird thing is the Pentacon frames differently than the other two lenses, there's a vertical shift which might be due to the tripod being moved, even though I seem to remember the Pentacon was the middle shot of the three. But the big surprise is the Tamron: at f2.5 it's washed out with very low contrast.

As I have already used the Tamron for normal shoots and always loved it, I took another shot closing it down by half a stop, which is what you see here: the two f2.8 lenses at f2.8, and the f2.5 Tamron closed by half a stop

This looks more like it: the Tamron looks as contrasty as the other lenses, with slightly more saturated colors.

Keeping in mind that perfect focusing at 2.5m with different lenses is not really possible (at least not with my camera and the Canon EG-S screen I have on it), and thus minor variations in focus might not be characteristic of the lens but due to my focusing, here are 100% crops from the above pictures

All three lenses look remarkably similar, with maybe the Fujinon having a slight edge in resolution with slightly less contrast, but again this might be due to manual focusing.

At f5.6

The lenses look remarkably similar to me, with the Fujinon maybe having a little bit more less contrast, possibly due to the front lens scratches.

100% crop at f5.6

Hard to say if the differences are due to the lens or to manual focusing differences.

100% crop at f5.6, subject at infinity

Very similar results, but here the color casts of each lens are evident: the slightly warmer Fujinon, the slightly cooler Pentacon, the slightly more saturated Tamron.

I'd appreciate your comments on these lenses, as it makes no sense for me to have three 100mm, and one of the reasons for me to compare them was to decide what to keep. I am thinking I will probably sell the Pentacon, as it's very very similar to the Fujinon and is in much better shape.

If you want to look at the original full-scale images, they are here.

woodrim · Joined: 14 Jan 2010 Posts: 4060 Location: Charleston

I agree that the Pentagon trails the others in all images. And that framing problem is strange.

ludoo · Expire: 2011-12-05

scsambrook · Expire: 2011-11-18

Firstly, all of them look pretty good on my screen. I think your slightly disappointing result with the Tamron at f2.5 is probably down to the designer(s) going for that extra fraction of a stop - I believe it's called "stetching". Given its age and use of only four elements, my guess is that the marketing department drove the technicians in this case.

Given that their performance seems to be very close, I'd keep the one which handles best (smooth focusing movement, crisp diaphragm operation and so on). If that's a draw, then I'd keep the one which is in the best optical condition. I know the Fujinon works well despite the marks, but you'll always have more confidence in a clean one.

folderholder · Joined: 24 Jan 2010 Posts: 102 Location: California

I find the out of focus backgrounds to be quite interesting. Maybe it's an illusion due to greater contrast but at f/5.6 the Tamron seems to have a bit more depth of field than the others. The Fujinon bokeh is distinctive. Overall I prefer the Tamron except wide open.

pat donnelly · Posted: Sun Feb 28, 2010 12:12 pm Post subject: pORTRAIT LENGTH LENSES

tHE 2.5 STOP WIDE APERTURE SOFTNESS OF THE tAMRON IS VERY USEFUL FOR THOSE PORTRAIT SUBJECTS WHO NEED A LITTLE MORE MAKE UP FOR WHATEVER REASON.
Sorry, just noticed the caps lock. My cockatoo not only messes with that, he also bids on eBay!.

Effectively it is a "soft" lens but only at that aperture. And on a FF or APS-c camera, at a stretch. What a bonus! I expect the more modern Tamrons will have eliminated that and that is why this post is so good!

Thanks.

The pentacon parallax is disturbing. An SLR eliminates this? Yet it occurs consistently and has to count against the lens?

ludoo · Expire: 2011-12-05

Interesting observation about the soft rendering of the Tamron, in fact it might come in handy for portraits, and knowing that half a stop more makes the lens sharp and contrasty is pretty useful in normal shooting.

What I did not think to check in the pictures above is corner sharpness. They are not ideal to do so as corners are mostly out of focus, but at a quick glance (you'll need to use the full pictures linked in my first post) the Pentacon seems to be the better of the bunch in the corners.

As for the Pentacon parallax, I might have bumped on the tripod when I removed the camera to change lenses. I will take a quick couple of test shots to verufy this issue.

fish4570 · Expire: 2012-03-21

i like the one on the left. i can't tell you why ...

woodrim · Joined: 14 Jan 2010 Posts: 4060 Location: Charleston

martinsmith99 · Expire: 2013-11-18

To me the Fujinon wins with the Pentacon 2nd.

no-X · Posted: Sun Feb 28, 2010 5:08 pm Post subject:

I like the Pentacon more than Fujinon - it has smoother bokeh and slightly less CA.