Nippon Camera Article about FA lenses
I picked up the June issue of one of Japan's main photography magazines, "Nippon Camera" today and found an interesting article about FA lenses on the new 645Z. The authors appear to have had a pre-production model on hand and took lots of photos with a variety of FA lenses to see how they work. I'm not sure I agree with everything they said but will give you all the general points of the article and the FA lens summaries.
First off, they talk about the backlash against the mega-pixel race, pointing out that recently manufacturers of FF cameras have begun to select lower pixel counts in an attempt to get lower pixel density or pitch. The author contends that when you cram too many pixels into a small camera the main problem is that you end up with a sensor that requires absolutely top class glass in order to yield it's best. This potentially puts the manufacturers in the position of having to redesign all of their lenses to a higher spec, which is fiscally impractical. But if you have a sensor with lower pixel density and a larger pixel pitch it becomes more forgiving with regard to lenses. (I confess I have never heard this angle on the pros and cons of high pixel count vs. low pixel count and am not sure if I find it entirely convincing.)
And while 50 mega pixels is awfully high, the author says that because of the physical size of the 645Z sensor, the pixel density is low enough to make for a forgiving sensor. Having said that, the question at hand is how the decades old FA lenses will perform on the 645Z. The author gives each lens a star rating based on a five star scale. Here are the results and comments. It should be noted that stars are not based exclusively on performance, but take price into account as well. MSRP is listed for all lenses in the data.
33-55/4.5 Four stars: even with lens distortion correction turned off, the distortion is rather negligible. But there is some visible moire.
35/3.5 Five stars: High resolution, good sharpness in the edges, and resistance to flare even with semi-direct light source
45-85/4.5 Four stars: even stopped down to f/45 there is less refraction than expected and it maintains sharpness well too
25/4 Five stars: The widest lens available, made for digital, and reveals superior detail sharpness
45/2.8 Two stars: Compared to the other FA lenses edges are lacking in sharpness. May not be suitable for use with the 645Z
55-110/5.6 Two stars: Originally intended as a standard zoom on the 645, it ends up being an awkward focal range on the 645Z. Image quality doesn't stand out as being particularly good or bad.
55/2.8 Five stars: Even sharpness edge to edge. We recommend this one as it is the most affordable of the D-FA lenses.
75/2.8 Four stars: The original standard lens.It's 30 years old but still has great clarity and and contrast. Excellent lens in terms of cost/performance
200/4 Four stars: 35mm equivalent is 157mm, making it a mid-tele. While not a particularly fast lens, it has very nice bokeh
400/5.6 ED Three stars: 35mm equivalent is 315mm. Given the improved AF motor of the 645Z, AF tracking performance is very good.
150-300/5.6 ED Five stars: This was a popular tele-zoom with the old 645. A good value when you compare the price with the 300mm prime.
300/4 ED Four stars: I remember being shocked by the image quality of this lens when using it on film. It still is impressive, but the high price is a bit of a detriment.
Macro 90/2.8 ED Four stars: This is the only HD lens in the series. The image quality is beyond reproach, but the price is "top class" as well.
150/2.8 Five stars: A fast, mid-tele lens in the film days, this lens doesn't get a lot of attention, but the bokeh and sharpness are excellent.
300/5.6 ED Five stars: Pentax held the price down by making this lens one stop slower, but because of the ED, it controls CA very well and is a great match for the 645Z
Macro 120/4 Five stars: This lens breathes life into the fine details of a leaf surface. It also provides a more comfortable working distance than the D-FA macro, and is much easier on the wallet at less than 1/3 the price.
Thee more items were feature. First a direct comparison of the new D-FA 55 and the older FA 45-85mm at 55mm. While there was some difference in edge sharpness with the newer lens looking better the overall impression was that the older zoom competes pretty respectably with the newer prime.
Secondly, the A-series teleconverters were tested with the FA 400/5.6. Not much was said other than that they work, and that since the t/c's are from the A-series they don't have any chip which means the in-camera lens correction functions don't work and some fringing may result.
Thirdly, the SMC Pentax 67 Soft 120/3.5 was tested with the mount adapter. Due to the cropping of the 645Z, some of the roughest edges are eliminated and the resulting effect was a very pleasing soft-lens look.
Fourthly, the A-series manual focus macro 120/4 was tested. Once again, all in-body lens correction features don't work with A-series lenses but CA was minimal and overall clarity and sharpness were very good. Used prices are very competitive, making this an attractive option.
In the final section they talked about the quality of the Pentax 645 lenses and made some interesting assertions. According to this author, prior to the release of the Pentax 645 lenses, most medium format lenses were of inferior quality, especially in comparison to 35mm lenses. This was because medium format lens makers had to deal with the challenge of creating a bigger image circle and this ended up taking most of their resources so they tended to compromise on image quality. But they were able to get away with this because of the larger negative and subsequently higher resolution. On the other hand, 35mm photography frequently required more extreme magnification in printing so manufacturers were forced to produce extremely high quality lenses. But then with the release of the Pentax 645 series lenses in 1984, for the first time a manufacturer started making medium format lenses that were of the same high quality as 35mm lenses. (Once again, I'm not sure if I actually believe this analysis or not)
In the final analysis, the author is very impressed with the FA series lenses and admits that initially he felt like they were simply filling the void until a fuller D-FA lineup was created, but now he has come to view these lenses as completely compatible and worthy of use with the 645Z. He also points out that their primary advantage over the manual focus A-series is the presence of an in-lens chip which allows the camera to apply lens correction of four varieties; none of which will work with A-series lenses.
So there you have it. If nothing else, this new camera is generating a lot of attention.
|