Just Finished Testing My 300-M and 300 APO Ronar

[Scott Rosenberg]

i am presently assembling a lens kit designed specifically for backpacking... small and light is the order of the day. for my moderate long lens, i decided on either the 300mm Rodenstock APO Ronar or the 300mm Nikkor-M. the ronar, with a blue stripe on the barrel, is from the latest run. the Nikkor looks like new, while I can't date it, it's SN is XXX404.

i understand that my findings are valid only for the two particular lenses in my possession, and a different 300-M and 300-Ronar might have yielded vastly different results. so, should these findings be considered gospel applicable to all 300-M and 300-Ronar lenses - absolutely not. i am posting them simply to share what i found about these two particular lenses, as i thought others might find it interesting. that said, here's the good stuff...

i should preface this analysis by saying that i was biased towards the 300-M from the beginning. it is slightly smaller than the 300-Ronar, though not appreciably so, but remember, i am on a quest for small lenses. so, the 300-M was in my favor straight out of the gate.

i took images (f/16) of small objects with fine detail, as well as a USAF resolution chart, ranging in distance from around 8 feet to infinity. i then analyzed 14 image pairs cut from the larger images to zero in on the details i was interested in. using this method, i could fit both small crops under my 6x loupe at the same time, making careful analysis possible. i then went back with a 50x loupe to corroborate my findings.

in all cases save one, i observed the whilst the Nikon lens was slightly more contrasty, the Rodenstock resolved fine detail far better. in the cases of the really small stuff, the Ronar enabled me to make out what i was looking at, while the Nikon softly blurred out.

i was so surprised by these results, or maybe i was just hoping that the smaller 300-M would win the day, that i repeated my study. the results were identical. both lenses are very sharp, and had i not bothered to go to these lengths, I'm sure i would be happy with either. if the ronar is this good now, i wonder if it will be even better if i send it to linos to be optimized for infinity!

again, these results are only applicable to the two lenses i have presently, but i thought some of you might find it interesting.