Legacy lenses pros, cons and considerations
We've seen how adapting manual lenses came to be a modern photographic fashion, in the first part of this installment. Let's now have a look at the pros and cons of adapting, but first let me preface that by emphasizing that this is an introductory article, not meant for experts, but rather more to the people with no, or limited, experience on the matter.
Let's start with the advantages:
It goes without saying; if one already has lenses from a film camera system, maybe forgotten in a drawer somewhere, adapting is a great way to expand ones expressive palette.
Although prices of (good quality) legacy lenses have virtually skyrocketed in recent years, there are still some, literally, jewels of a lens that can be found for a modest price. On the other hand, even quite expensive legacy lenses are most of the time almost half the price of a modern equivalent; case in point a number of f/1.2 and f/1.4 examples in 50 and 85mm focal lengths. In many other cases, a couple or more of good quality primes can be obtained for the same price as a mediocre modern zoom lens.
- Great optics
Not all legacy glass was created equal. But, in some cases (most notably Zeiss and of course Leica) the optical formulas are so good that they practically continue to be used in today's brand new examples.
- Construction quality
Even the cheapest of legacy lenses were created in an era when photographic equipment of the sort was not a consumer commodity. As a result, they were not plastic little toys, as is the reality of most of the massively produced cheap lenses today. They were mostly made of metal and, because they are quite simple designs, even repairing one is much less of a hassle than today's electronically laden versions.
If there is one characteristic almost unique in using legacy lenses, is that, even dirt cheap models, many times exhibit a kind of special image rendering which bestows a special or even unusual character. This is very sought after by videographers but traditional photographers also; it might be a distinctive color rendition, a particular type of "glow", a certain kind of micro-contrast or, for most people, the quality of the bokeh.
- Cross system compatibility
This is one advantage of using legacy glass that is often overlooked. If you use a number of different cameras/systems, all you need is the appropriate adapter and the same manual lenses work the same way. Well, almost the same way, as we'll see in the section on crop factor.
Naturally, there is no such thing as a free lunch, and we have to take note of a number of potential problems and/or considerations:
- Problems due to old age
Let's make it clear we are talking about lenses that can be several decades old; sometimes much older than the aspiring "adaptive photographer"! Issues with haze, fungus or oil on the aperture blades are not uncommon. Unfortunately, it's very difficult to judge condition by photos on ebay, and, even if there is an actual problem, even the seller may not have the experience to notice it. There is no easy way around it: as with any used item, you take your chances. It helps if you can order by reputable sellers, and this is why many people like to buy only lenses they can test themselves or from an online shop with experience in such stock.
As noted, old lenses are metal and glass, in other words, heavy. Some people are surprised that even a pancake type lens weights more than their much larger modern kit lens. This introduces some fears on the longevity of the camera mount, if one is not reasonably careful. With longer telephotos, in particular, caution must be exercised while operating the camera.
The one thing changed in the development of modern lenses, was the gradual introduction of lens coatings, going from single-coated to multi-coated to modern nano-particles coating of internal elements. Older lenses may lack the coatings necessary for modern camera sensors, which may result in flare, loss of contrast, glow and haze, and general image degradation, under certain conditions. Of course, many people view such behavior as contributing to the "character" of a particular lens. For all other people, it's important to read about the lenses they intent on using, and how well they play with digital sensors.
- No in-camera corrections
An awful lot of today's camera lenses rely on in-camera lens correction algorithms, to correct geometric or color discrepancies, due to lens design. Things like vigneting or chromatic aberrations are easily controlled by in-camera software nowadays; and even if they're not, lens profiles are available to use in post-processing software. This is not the case with older lenses, which means that, in some cases, more post processing work is needed.
- Αlignment issues
This is a consideration that surfaced with the Sony a7r in particular. Some people noted that, a number of adapters, had side to side alignment inconsistencies. This was probably always the case, and just became evident with the high pixel count of this camera. Worthy of note is that, even some number of native modern lenses have similar problems with high resolution cameras, such as the Nikon D800. It's worth investing in the best quality adapter one can afford; having said that, minor alignment problems will not be evident in low(-ish) pixel count cameras (i.e. less than 20Mp).
- Loss of some light
There is a slight loss of light with some longer adapters, simply because you have a piece of black painted metal tube between the lens and camera. It's not anything serious, just worth mentioning.
- Crop factor considerations
This is an area where use of older lenses can be considered either a blessing or a curse. It merits some deeper analysis.
The point is, most older lenses were made to cover the 35mm film area; the same as today's "full frame" camera sensors. There were some notable exceptions, like the old Pen lenses, but in general 35mm was the standard.
When such a lens is used in a crop-sensor camera, such as APS-C or Micro Four Thirds, the field of view is redefined by the crop-factor; 1.5x or 1.6x for APS-C and 2x for m43. Which means, a 100mm lens becomes equivalent to 200mm for FoV. On crop-sensors, this might be desirable; e.g. for having a "free" very long telephoto reach. But it also means adapting wide-angle lenses is not so desirable.
There is also a benefit for crop-sensor cameras, which is that, the smaller sensor will use only a smaller central section of the lens' image circle. This leads to much less distortion, vigneting and other image flaws, that would be evident in a 35mm-size sensor (depending on the lens, of course). In some cases, this means a lens can be more easily used wide-open, with no need to stop down to make it sharper in the corners or get rid of geometric imperfections.
There is also the recent introduction of focal-reducer type adaptors, for crop-sensor cameras, which is worth a chapter all by itself, and indeed one is coming in this space, soon!
In a future post we will examine a number of systems worth adapting to modern cameras, complete with examples reference links for anyone interested. I will also occasionally post some examples of my own use of adapted lenses, with photo examples and comments. Stay tuned!