© Robert I. Sadler, 2011
Description & Specifications
Depth of Field Guide
| f/6·3 | ||
|---|---|---|
| 2·50 | 2·49 | 2·51 |
| 3·00 | 2·98 | 3·02 |
| 4·00 | 3·97 | 4·03 |
| 5·00 | 4·95 | 5·05 |
| 7·00 | 6·90 | 7·11 |
| 10·00 | 9·79 | 10·22 |
| 15·00 | 14·52 | 15·51 |
| 50·00 | 44·99 | 56·26 |
| ∞ | 256·05 | ∞ |
(Distances in metres; Circle of Confusion is taken at 0·032 millimetres.)
Review
This is a nice looking lens, that delivers average image quality. Basically constructed out of three tubes held together with set-screws, with an interchangable mount. The distance scale is there, but that's it.
The lens elements appear to be uncoated, but maybe they're just thinly single-coated. Whatever, because it does impact on the optical quality. There’s a lot of haziness if the lens is pointed anywhere near the sun or bright object. I slapped on a skylight filter — the only one I had in ø 62mm — and the optical quality nearly tripled!
Sharpness and resolution is alright, but I get better images upscaling from my Canon EF 70-200mm f/4 L USM lens to 300mm equivalent. I'd say it is on par with the Canon EF 75-300mm f/4-5.6 III USM lens. Chromatic aberrations are there, but significantly reduced by using a filter.
The fixed aperture of f/6·3 is acceptable and doesn't make manual focussing extremely difficult.
What is a let-down is the size of the lens. It’s not much smaller than most 500mm catadioptric lenses and 300mm isn’t good enough to justify carry it around for just in case. Besides, a good quality filter actually does cost more than this lens sells for on the secondhand market.
If you have never owner a catadioptric lens and want to play with doughnuts, then this lens is a cheap enough experiment and well worth a Rand or five — just remember the extra couple of hundred for the filter. Otherwise, go for a quality 500mm mirror lens.
On the other hand, just for fun I tested this lens with a Soligor Auto Tele Converter 2X, thus creating a 600mm f/13 lens. Strangely, the lens doesn't darken the focus screen as much as expected, which means manual focussing is easy enough. Optical quality remains mediocre, but still very much acceptable — unless you pixel-peep. Let’s face it, you get what you pay for it.
Recommended: No