smc-m 20/f4 - is someone using it? I need some opinions.


Link Posted 13/10/2004 - 08:41
my first post here, but not last for sure.
i`m using z-1p and me-super + a set of prime lenses (50/1.4; 135/2.5; 24/2..

i want to ask you about smc-m 20/f4 performance - resolution and sharpness (expecially in the corners), what is your experience with it?
is it worth ~320$ ?
i`ll be using it for shooting architecture, also night photos, some macro (photos of the architectural cardboard-models).
from time to time i would like to print an A3 enlargement. is this lens ok for that?
what kind of film you were using with it to get satisfactory results in printing big enlargements.



Link Posted 13/10/2004 - 16:37
The SMC Pentax-M 20mm f4 is one of my favourite lenses, and I use it a lot.

Sharpness is exemplary and A3 or larger prints will not be a problem. The lens is compact, smooth as silk to operate, outstandingly sharp and with a clean, crisp image quality.

It is useable for architecture, but there may be a hint of barrel distortion that needs watching for critical reproduction of straight lines. This is, however, nowhere near as noticeable as on most modern wide zooms!

It's a fantastic lens!
Best regards, John


Link Posted 13/10/2004 - 17:01

i was worried if this lens is going to be better than my current exakta 24/2.8 (leaving the angle of view alone).

i wasn`t ever comparing it to zooms, cause i`ve never used one and am not intending to use in near future

i was also curious how is it compared to legendary flektogon, or other 20mm prime lenses in terms of resolution and distortions?

and is it worth the price?

thanks again.


Link Posted 13/10/2004 - 18:24
I think it's the very highest quality and although I have not used the lenses you mention, I am aware of their design and I would expect the Pentax lens to have the edge.

I'm sure it is worth the price generally asked, that, is, perhaps up to 200 or so. But hopefully less! I have seen them around 150.00

It is a more modern design than the lenses you mention, and will benefit from that. It also takes 49mm filters, a usefully inexpensive size.
Best regards, John


Link Posted 14/10/2004 - 08:36
big thanks for your answers,
i think i`ll go for it

the rest of hunting that i have left is for FA135/2.8
and this is kind of a problem - because there is not much of them on the second hand market, and a new one costs ~290 here in poland...


Kevin Stephens

Link Posted 07/11/2004 - 12:30
I've not seen any 20mm f4 for sale second hand, how much do they go for?

The current FA 20mm f2.8 seems extortionate at 600 GBP! I can't understand why/how Pentax can charge so much for this.

I will probably get a Sigma EX 20mm f1.8 for around 250
I can anticipate the howls of protest from those who tar all sima lenses with the same brush as their cheaper zooms, but i would be surprised to see 350 GBP of difference between 5400 dpi scans of trannies from the two lenses.



Link Posted 07/11/2004 - 13:33
The quality of any picture is only as good as the weakest link, so I think a pentax lens will make a difference. It's a matter or sharpness, accuracy of drawing (distortion), gradation, lack of flare....and of course the construction quality that ensures accurate alignment and long operational life. I tried a Sigma lens at an exhibition and the focusing and aperture were loose and sloppy and the rep said "It's been used a lot", which meant to me that it was not up to hard use over a long period of time.

The Pentax lens is expensive, but I would buy it without hesitation if I could afford it, but I can't! So I have a second hand SMC Pentax-M 20mm f4 in superb condition that does the job just as well. Cost - probablt 125-250 depending on what you can find.
Best regards, John

Kim C

Link Posted 07/11/2004 - 13:50
I would go along with what John said. I used to have a K version of the 20/F4. It was a good lens but like the M version did suffer from quite a bit of distortion and this will show regardless of the resolution. I now have the A version of the 20/F2.8 which is the same construction as the FA. I can honestly say that the difference between this and the F4 is remarkable. I paid just over 300 for it in near mint condition. With this angle of view, I would pfefer a manual focus version over the FA. With the depth of field involved it is quicker to use. As to the Pentax quality, much has been said in these pages on the quality of the "standard" lenses. I don't dispute any of it but they are outclassed by the 43mm "Ltd" lens. The image and build quality of this lens and it's 31mm brother is fantastic. ( only wish I could get hold of a 77 at a good price )



Link Posted 07/11/2004 - 14:36
I agree with Kim regarding the distortion of the 20mm f4 M lens, and this is why it is very useful to know what a lens has been designed for, and to think of what you want to use it for. The distortion does not upset me too much because I am shooting landscapes with the lens, and it is not much of a problem. If I was shooting architecture I would want something with more accurate drawing.

Having said that, a lot of modern lenses, particularly zooms, are very, very sharp but have very poor control of ditortion. It could well be that for general purpose lenses distortion is the one parameter allowed to drift a little in exchange for the sharpness that many people expect.
Best regards, John

Kevin Stephens

Link Posted 07/11/2004 - 16:16
congratulations on the second hand prices John and Kim found for the 20mm f4 and f2.8

After trawling the net and AP the best i have found recently is Nichols in London, asking 345 for the f4 and 425 for the f2.8.

I guess these rarer lenses will continue to rise in price.

Also found a second hand FA 20/2.8 at 399, better lock up my credit card now!


Link Posted 07/11/2004 - 19:49
I know what you mean, but to be honest if over the years I had bought what I wanted instead of trying cheaper options, finding they were under par, buying something else.......It could be less expensive in the long run to just let the credit card creak a little in the short term and make just one purchase that actually does what you want it to.

Just a thought!
Best regards, John


Link Posted 11/11/2004 - 04:33
I once had the M 4/20 - and although it's a fun to use....
I sold it again.
Visible vignetting (much more than Zeiss Jena Flektogon 2.8/20)
contrast in the corners is lacking too.
Others have already metioned that esp. with ultra-wide-angles (like this 20 mm) more modern designs have been improved. Therefore I would look for a new designed 20mm.

As for the focal length:
Yes, it's worth to have a 20mm aditionally to 24mm (esp. when the 24mm is only the cheap Exakta - oh yes, I had that one too).
If you want a cheap wide-angle with quite good results I can recommend the Vivitar 3.9/19mm (often sold as 3.9/20 - but they are equal).
I got it at ...bay from a german power-seller named Foto-Walser. At an ordinary auction you may get it for about 70,- - 85,- EURO (new !).

Once you started with ultra-wides you may always want it another bit wider - it's like a virus....
So you may look for those new ultra-wide zoom-lenses....?

Best wishes for your decision

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