Today I went through a huge number of pics I had saved in my laptop in jpg format.
I was trying to clean the clutter and free some space, as I have transferred long ago both raw archives to USB drives and posted some of the most relevant online, on different fora/sites. Which actually means that I have no use for many jpg's that are just eating up precious space on internal HD's (I have two, one SSD and one traditional, in place of the DVD).
Erasing dozens and dozens of jpg files I found a test I did long time ago, whose very existence had completely slipped out of my memory.
One interesting set was a test of three M42 lenses, made with a K10D camera (which I still have, equipped with a chinese plastic ground glass with diagonal stigmometer and microprisms).
The lenses that were tested were a Meyer Lydith 30mm, its Pentacon successor with identical optical layout, and a Panagor 2.5/28mm. The latter is practically identical to the Kino-made Vivitar that of course is present in the Vivitar 28mm Bestiary Internet page.
Examining the shots at 100% I found that the best lens is the oldest of the three, the Lydith.
It beats by a small margin the Pentacon (which should have a slightly better coating), and by an important margin the Panagor.
It's not what I would have expected, as the Pentacon and the Panagor are in very good shape, while the Lydith example I tested has a small scratch and some coating blemishes on the front glass.
Recently I am trying to buy vintage lenses in perfect shape, while in the past I wanted to try them, and I was happy to acquire examples that were in less than ideal conditions.
Well, it seems I was right!
The images from that quick test seem to confirm what I have learnt with practice: a spotless glass (especially the front one) is not a necessary precondition to punchy, detailed pictures.
Some vintage lenses have so-and-so front glass and work great, while others look perfectly fine... but they are out of whack, and perform accordingly!
Some might even be like that from day one. It is widely believed that soviet lenses had QC problems towards the end of the Soviet Union.
The same way, some historical german brands had slowly worsening assembly standards towards the end of their activity.
However, I guess that most lenses were perfectly fine when they left the factory, but over a long period of time they might have been wrongly/carelessly reassembled. Others sustained strong impacts, which could have left no traces, because some lenses were built like tanks!
All in all, most vintage optics are quite impervious to "accidents", unlike modern AF zooms with plastic zoom and focusing sleeves.
Though some are actually totally out of spec, and it happens that every now and then I realise I got a lemon.
Sometimes it's just hazy, and it's easy to restore it to its former glory.
Sometimes the optics are misaligned, or (even worse) there are missing distancing rings or other major problems.
I think I have never found a hugely disappointing lens that is underperforming because of glass damage, unless it's a real disaster, like a front glass practically sanded down by repeated attempts to clean the lens without blowing off sand particles.
I have seen few lenses in that conditions, but I have seen some that had large part of the very soft coating completely removed.
I am asking for some stories that would confirm my point (or eventually disagree).
Maybe some funny/extreme story. I know of a micro Nikkor that was etched with the tip of an iron nail by a child, and was tested afterwards by my repairman, proving as sharp and with practically no decrease in contrast!
It would be interesting to understand if you would ever buy a lens with a visibly damaged front glass, knowing for sure that it would not affect the performance.
In all sincerity, I got a bit snobby under this point of view. I guess because half of my brain thinks as a collector, and not in practical terms of photographic output (the actual quality of the final image).
At the same time, it is also true that I recently bought a few vintage lenses, knowing that they had fungus/haze problems, because I wanted to take the chance to fix them, and because a mint example would cost a little fortune...
I realise that I always carefully check the pictures OF the lens, but I almost never have the chance to actually see any picture made WITH the lens I am going to buy. I should try to ask for sample images, but it's not always possible.
Despite taking some risks, and ending up with optics in far worse condition than I expected, fortunately I found that some of the objectives that have some glass imperfection are among my favorite.
Maybe I would never buy any of them now, if I was aware of the problem, but I am glad I did when I was more interested in trying new vintage lenses at a decent price than having collector grade examples... which by the way may even get less use because of their value.
I am not sure I would carelessly throw in a soft groceries bag (together with a low value K10D or K-01) my recently CLA'ed Primoplan or my beautiful 8-elements Super Tak, as I often do with other low value or very "experienced" optics.
An imperfect lens is always better than no lens at all. I found that some of the best shots come unexpected, and having a camera/lens you are not afraid to lose or ruin can make those shots possible... and it's great if when you get home you find that the "imperfect" glass works pretty well!
Last edited by cyberjunkie; 11-30-2018 at 06:15 AM.