CONCLUSION

Similar to the Zeiss 28mm F2 Distagon ZE, the 50mm Makro Planar’s signature / fingerprint is most apparent at close focusing distances. For landscape work at mid distances and infinity 50mm Makro-Planar performs admirably, however, the fingerprint is less distinctive. To my eyes the images look much like that of any good 50mm lens stopped to around F5.6 or F8. On one hand this could be interpreted as a good thing because the lens is flexible enough to go from extreme close-ups to infinity and perform all roles in between. Or, the lack of distinction could be considered as a detriment.

1. •As a walk around lens:  In my kit the 50mm Makro-Planar’s greatest competition comes from the Canon 24-105L F4 IS. Assuming typical walk-around use during a vacation, the question for me is - “would I take the 24-105L off the 1Ds Mark III to use the 50mm Makro-Planar for a landscape shot?” Mostly like not. The 50mm Makro Planar resolves more details than the 24-105L F4 IS; however, for typical walk-around use, the 24-105L F4 IS is fine in my opinion.
   

2. It is a difficult decision because the 24-105L IS offers the flexibility of a zoom and auto-focus; whereas the 50mm Makro-Planar offers higher resolution and a faster aperture, but not the flexibility of a zoom (remember, I am only talking about walk-around use at the moment). If shooting close-up and/or at wide apertures, then I would prefer the Zeiss 50mm Makro-Planar over the Canon 24-105L IS. For stopped-down snapshots, I would probably pick the 24-105L because of its ease of use.
   

3. •Indoor shooting:  Another critical consideration is the 50mm Makro-Planar’s F2 aperture. For indoor use in low-light conditions I feel F1.4 is a “must-have”. When shooting indoors at our house or when out & about at the local restaurants, F2 is not fast enough. At ISO 1600 and F2 the typical shutter speeds have been around 1/30th - and that is too slow for sharp handheld images. I suspect the 50mm Makro-Planar is not efficient in gathering light. This characteristic is measured in T-stops.
   

4. In a theoretically perfect lens the F-stop and T-stop would be equal. In reality each lens element absorbs a tiny amount of light, thus slightly less light is transmitted as the light passes through each successive element in the lens. Light transmission is affected by the type of glass used, the number of elements, the element design (such as thickness) and the coatings used. Some lenses are very efficient and the absorption is minimal. Other lenses are less efficient the result is somewhat slower shutter speeds (than expected).
   

5. If shooting in low-light conditions and not using a flash for fill light, then the 50mm Makro-Planar is not the best candidate. Curiously, the 28mm ZE seems very good at finding light and has been a pleasant surprise in low-light conditions. For low-light use lenses like the  Canon 35L or 85L are great choices. This may change in 2010 as Canon is promising ISO 102,400 in the Canon 1D Mark IV. If the 1Ds Mark IV can deliver an ISO 6400 as good as the Canon 1Ds Mark III’s ISO 1600, then all this aperture / shutter speed / t-stop mumbo-jumbo is moot.
   

IS THE 50/2 ZE RIGHT FOR YOU?

I think the 50mm Makro-Planar is an excellent lens; however, there are other 50mm lens options which may be more cost effective. Whether the 50mm Makro-Planar is a good choice purchase decision depends on shooting style and preferences. The following list of considerations may help you decide if the 50mm Makro-Planar is a good lens for your needs -

1. •Are you planning to shoot in low-light conditions?
   

2. ➡If yes, then consider a F1.4 50mm lens instead.
   

3. •Will the lens be used mostly for F4-F11 landscapes?
   

4. ➡If yes, buy a cheaper 50mm lens and save some money.
   

5. •A happy 50mm Makro Planar owner most likely -
   

6. ➡Prefers to shoot at near and mid distances.
   

7. ➡Needs or would like to have a macro lens.
   

8. ➡Prefers Zeiss colors and contrast.
   

9. ➡Enjoys using wide apertures and thin depth-of-field.
   

10. ➡Is comfortable with manual focus lenses.
    

The Zeiss ZE line is not a mass market consumer lens line-up. First and foremost the Zeiss ZE lenses are expensive. The standard Canon EF 50mm F1.4 USM costs ~$379 USD, so paying essentially 3X more for the Zeiss 50mm F2 Makro-Planar ZE merits careful consideration. For the Zeiss fanboys (and I’ll include myself in this group), the 50/2 ZE is a no brainer. For Canon 5D Mark II and Canon 1Ds Mark III owners looking to maximize their 21 MP sensors, again, the 50/2 ZE could be considered a no-brainer. For everyone else, whether or not to buy a 50/2 ZE might lead to some sleepless nights.