Vivitar 20mm f3.8

[guardian]

I made mention of this lens on another thread and received a response from iangreenhalgh1. I'm starting this thread in order not to steer that other thread off topic, and in order that people interested in this lens be able more easily to find applicable postings.

Here is what I wrote on the other thread:

"I bought, probably in 2013, a Vivitar 20mm f3.8 lens for circa US$30 all in. The lens is in like new shape, it arrived in the original box, and most likely it is new. However, this lens has a fixed KAR mount, so is less desirable. Lens is probably Tokina."

Here is Ian's response:

"The Vivitar 3.8/20 is the Cosina 3.8/19 rebadged. Not a very good lens, most copies are decentred, poor coatings, very flare prone, flat contrast, muted colours."

Ian is knowledgeable, of course. But my Vivitar lens was made in 1976. Prompted by Ian's post I actually retrieved my lens and brought it out of storage. I see it carries a serial number beginning with "22". My changed thinking now is that this lens was made by Kino Optical, aka, Kiron.

For anyone interested in the quality of the lens, this video is quite good and is very descriptive:

https://www.youtube.com/watch?v=Up9_jGJ6Nes

As I wrote earlier, the key disadvantage of my lens is the fixed mount. This is something I have encountered countless times with these Kiron lenses, where the wrong fixed mount kills a deal for me. In this instance however, the price was sufficiently low and the condition of the lens was so good that I had to buy the lens regardless. Some day, if I ever can afford a FF mirrorless camera body, this lens will shine!

ETA

Here is more information regarding this lens:

https://www.youtube.com/watch?v=hokXJNSBYWs

[iangreenhalgh1]

Just show us a picture of the lens, then we can ID it.

[LucisPictor]

I had this lens in altogether three different incarnations
One of them was acceptable, the others were not really good.

But I guess this lens model also can pop up somewhere as a very good copy where coincidentally everything is fine.

[guardian]

[iangreenhalgh1]

Yes, that is a Kiron.

The Cosina version is much more common and is a poor lens, cheap and plastic.

It is seen marked both 19 and 20mm.

Here it is as a Vivitar 19mm:



http://allphotolenses.com/lenses/item/c_603.html

As a Cosina 20mm:

http://allphotolenses.com/lenses/item/c_603.html

[guardian]

[LucisPictor]

Ah, OK! Yes, that Kiron version is much better. I had the chance to use one on my NEX-7 (when I still had it) and it performed much better than the smaller 3.8/20 one.

[scsambrook]

[iangreenhalgh1]

Well, my comment on the quality of the Cosina 20mm has to be taken in the context that it was spoken, which is the current digital world.

Yes, it was a cheap lens, and it does do the job, but let me be clear on why I categorised it as 'poor':

* Ineffective coating(s) - even a bright sky in the top of the frame could induce terrible veiling flare, even when the sun was behind your back.

* Softness across the entire frame until stopped down 2 stops.

* Smeary soft edges even at f8 on an APS-C camera.

* Right side of the frame worse than the left by a fair margin - lens is badly decentred.

* Cheap, plastic build quality - mine, despite looking news, was very loose and had lots of play in the focus, it wobbled, which didn't inspire confidence it would survive many years of use.

So while it may have been acceptable in the days of small colour prints, it's limitations are quite clear on a digital camera today.

Am I wrong to call it 'poor'? I guess that's a matter of perspective. Can't compare it to anything else as there are no other 20-ish lenses in the same ultra low price bracket. Closest would be an old Flektogon 4/20 or Russian copy thereof, and even those cost several times what the little plastic Cosina can be had for.

Finally, there is the major caveat that I can only talk about the one copy I had; however, many others concur with my low opinion so it is probably fairly representative of this lens.

[scsambrook]

Ian - clearly, your particular lens has plenty of shortcomings and you are quite correct to say now that " while it may have been acceptable in the days of small colour prints, it's limitations are quite clear on a digital camera today ". But that's not what you originally wrote, is it? You simply dismissed it out of hand.

Saying categorically and without any amplification that a lens is 'poor' carries a real risk that a newcomer to the Forum may end up grossly misinformed as to the reality, especially when it comes from someone who, going by the sheer number of posts made, seemingly has some authoritative knowledge. Those of us who do have experience owe it to everyone else to disseminate what we know in a responsible manner. If I wrote that " Yorkshiremen are mean and surly" you would, quite rightly be offended. If I wrote that "I know at least one Yorkshireman who is mean and surly", you would probably nod and say, "Yes, so do I".

Let me add quickly that I am a Yorkshireman who can, sometimes, be careful with his money and curmudgeonly in his disposition.

[iangreenhalgh1]

Hmm, I'm somewhat confused. What is it you are taking exception with? My assessment of this lens as 'poor' or the fact that I didn't write war and peace to explain why it was a poor lens?

[scsambrook]

[iangreenhalgh1]

Oh it's often easy to confuse me, especially in the morning!

I take the point about context, it makes sense.

[hemeterfilms]

I did post comparison shots between my Cosina (19mm) version of this lens and my Minolta 17mm in the other thread. I think the results tend to support the view that actually my copy is not that bad. I also find it gives the impression of being rather solidly built. Certainly for what I paid (about 40 pounds), compared to the Minolta it represents good value.

My quest for a good UWA for my A7 continues and I find myself being inexorably drawn to the CV Heliar III.