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Pentax SMC M 50mm f1.7

andrewk
Posted 12/10/2011 - 12:42 Link
I saw one of these revered lenses on Fleabay about a week back. I already have two 50mm lenses - both Rikenon, a f2 and a f1.7, which I am quite keen on. The MTF charts on Pbase also suggest that the Rikenons are at least competitive. So why bother .........

Well, the auction listing did say that the lens was like new - and Pentax lenses get lots of plaudits in this locale - and I do have and use two Pentax lenses that I use and like a lot, so I put what I thought was quite a modest bid on the SMC 50mm f1.7. To my extreme suprise, I won the lens for coppers over £18. It arrived two days ago - and goodness, it does look just like new!! It also came with a very new looking case too.

It didn't take long to take a handful of comparitive shots - at f2 and at f2.8 where I expected any differences to be the most pronounced. I do need to repeat the tests, more carefully, when it stops raining - but I *think* the Rikenon lenses might just have been retired.

Mmmm .......

Andrew
Edited by andrewk: 12/10/2011 - 12:44
Father Ted
Posted 12/10/2011 - 12:45 Link
A lot less than I paid for mine
Still, nice to hear of someone getting a bargain, (I don't doubt that this was your bargain, not me paying over the odds).

Can you post the comparative shots and explain them? Just so us novices know what it is you are looking for.
Getting there! Thanks to you guys

Pentax K10d, *istDL, Kit lens ( 18-55mm ), 50mm f1.7 lens, Tamron 70-300mm lens, Prinzflex 70-162 manual lens, Various old flashes.
Dangermouse
Posted 12/10/2011 - 13:56 Link
I recently came across a suspiciously familiar-looking lens by a company named Phenix. The optical formula/focal length/aperture combination suggests a sort-of copy of the Pentax-M lens, although it takes 52mm filters as opposed to the 49mm of the Pentax.
Matt

Shooting the Welsh Wilderness with K-m, KX, MX, ME Super and assorted lenses.
andrewk
Posted 12/10/2011 - 16:19 Link
Father Ted wrote:
Can you post the comparative shots and explain them?

Errr ........ as I rushed when I took the shots yesterday, I had another go today. This time, I took several shots with each lens, refocussing each time - and then picked those that seemed the sharpest for each lens. After doing that, the difference between the two lenses shrank considerably. Just for the record, the shots were taken as RAW and were processed in PSE8, using ACR 6.2 for RAW conversion. The only other processing was the default sharpening in ACR 6.2

This was the full frame .......
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This is a 100% crop from the photo taken by Lens A:
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and this is a crop taken from an identical frame by Lens B:
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Arguably, some of the cactus spines look a fraction sharper on the Lens A crops. I suspect, though, that this has more to do with the difficulty in focussing accurately than any difference between the two lenses. I also took photos which were focussed on the nearer cactus and also on the rocket blower. Try as I might, I cannot distinguish between the crops - nor can I see any difference in colour or in the rendering of out of focus areas.

My conclusion is that I need to do a lot more testing of different subjects in better light (so that I can use ISO 100 rather than 400) and wheel out the tripod, so that I can be sure that camera movement is not an issue. At the end, I reckon that all I'll prove is that they are both great lenses and there isn't a lot of difference between them.

Thoughts?

Andrew
Edited by andrewk: 12/10/2011 - 16:21
PierroJ
Posted 13/10/2011 - 13:27 Link
I have the 50/1.7 and love mine. I paid £20 + ( cant remember exactly ) but its silly money for a brilliant lens. These are some of the first shots with the lens, and used my family as guinea pigs

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smc
Posted 15/10/2011 - 04:47 Link
The Rikenons have a good following, and still go for good money, especially in Japan. There may be more image qualityt differences due to sample variation and how a lens has been treatwd over the years. Having said that, Pentax did something special when formulating the SMC coatings and you may see more difference in more challenging shooting condtions - high contrast or against the light/ side lightiging.
Edited by smc: 15/10/2011 - 04:48

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