In the first article in this series, Looking For The Perfect Normal, I outlined the goals of the search and described the five lenses I'll be examining. Here's the first of these, the Vivitar Series 1 Auto Wide Angle 28mm f/1.9 (designated M01 in my numbering scheme). This is the only lens in the test to bear the famed "Series 1" label. This lens is from the seventies and has the M42 screw mount, so you'll want to read Using A Manual Lens On A Pentax Digital SLR.
Over at Denis' Photography Pages the author has a page dedicated to Vivitar Lenses. He writes: "A very fast wideangle lens, especially for its day (1970's), of excellent quality. Highly sought after, it is a hard lens to find."
To this I can add the fact that it cost $305 back in 1978, quite a fortune in today's money. It comes up for sale rarely but fetches between $150 and $200 when it does. It is an excellent optical design, utilising floating elements to provide internal focusing. This means the lens does not change size when focusing. However I should note that the front element does rotate. This might be a nuisance for polarising filter use, though I would be set up on a tripod for landscape shots where I'd be likely to need a PF. Adjusting the filter rotation after focusing would not bother me in this application.
Like the other Vivitars, and unusual for its time, it is close focusing -- I measure about 25cm or 10". It is quite hefty at 334g and 62 mm in length. The focus grip is large and damped.
The front filter ring is 58mm in size. I fitted it with a generic metal wide-angle hood. I consider this a must for all of these lenses, since the front elements are not recessed and are quite susceptible to glare.
The aperture ring has 12 click stops from f/16 to f/1.9 (there is no half-way click between 16 and 11).
My copy is in excellent condition but did not come with a front cap. It hardly looks used at all. From its serial number it was made by Tokina.
What follows are some images taken with the M01. I should stress that these are not scientific tests, but neither are they random snapshots. Someone else can do MTF tests and the like -- I am happy with considered observation of more typical photos.
I took five shots at different apertures ranging from the maximum to minimum available: f/1.9, f/2.8, f/4, f/8 and f/16. First I did so at the minimum focus distance, then at the 24" mark on the barrel and finally at infinity. I processed each file through Adobe Camera Raw using the Auto setting, with Clarity pulled up to 40. I did no other sharpening or adjustments. These images are not optimised.
For each of the five apertures I cropped out a similar area and then saved as a JPG at 100%. Thus, the images were not down-sized in any way, though they do have JPG compression. Click through each image for the full-size version in Flickr.
First, at minimum focus distance.
At f/1.9 the image is soft, really soft. The front of the screwdriver is OOF relative to the ruler. Unseen in this crop is the light fall-off at the edges. Though obvious it is rather insignificant next to the general softness. At f/2.8 there is a lot more contrast plus detail, although the image seems front focused... my mistake. By f/4 there is significantly more detail: look at the texture of the ruler and the ledge itself. At f/8 the image is nice in every way. By f/16 there is a significant drop-off in all aspects of IQ.
Now, at 24".
The f/1.9 shot is again soft everywhere, but there is less obvious difference between f/2.8, f/4 and f/8. Accuracy of focus plays a larger role that optical quality in the appeal of the final image in this aperture range. And f/16 here looks much like it did before.
There are differences in exposure in these pictures, which make it more difficult to compare them fairly. But the results look similar to what we have seen before. I would not use this lens at either aperture extreme, but in the middle range it seems fine.
In use I noticed that trap focus does not work. This might be a characteristic of M42 mount lenses. I'm new to them and so can't be definitive. But the viewfinder focus indicator was operational (except, oddly, at f/16).
I note that even with a hood the lens was susceptible to glare. I am sure the lens coatings were not optimised in these old lenses, at least not compared to modern standards.
Finally, a full shot at f/8 that I processed using my normal workflow. This demonstrates perhaps more realistically what the lens can achieve.