Which version of Jupiter-9 is the sharpest? Read on!

[aoleg]

I collected three different version of Jupiter-9 in order to discover which one's the best. Here are the contenders:

- MC Jupiter-9, M42. Bought new. Made in 2007 in Lytarkino.
- Black Jupiter-9, M39 (SLR). Got it as a gift from father-in-law who bought it new back then and used very little. Made in 1969 in Lytarkino.
- Silver Jupiter-9, M39 (SLR). Bought used here. History unknown, has signs of multiple invasions, has misadjusted aperture control ring, but I figured that out in the testing. Made in 1965 in Lytarkino.

All lenses were used with a very long hood to combat flare.

Color balance

MC version: neutral, slightly cool.
Black: greenish tint.
Silver: warm tint.

Contrast

I saw no discernable difference in contrast. I did not shoot against the light though, and the hood certainly helps.

Sharpness

It gets really interesting here. I shot the lenses side by side at f/2 and f/2.8.

MC version: STRONG SOFT FOCUS effect at f/2 with halos around bright objects. Very sharp at f/2.8. (Flares in contra light, but less than both SC versions).

Black: no soft focus wide open. This copy was the sharpest at f/2. Very sharp at f/2.8. (This lens is very prone to flare in contra light).

Silver: no soft focus effect; reasonably soft wide open; rather sharp at f/2.8. I say it's very similar to the black version; might be copy variation or prior service history that made this lens softer than the black M39 version.

Conclusion

If you're looking for the sharpest Jupiter, get an all-black, old-style metal barrel lens. Modern MC versions exhibit strong soft-focus effect wide open; if that's what you are after, then go for it. By f/2.8, all samples perform very similar.

[Xpres]

I did a very similar experiment with the same lenses and an old style black M42 mount as well. Same conclusions except for me the M39 silver was sharper than the black wide open.

[aoleg]

[martinsmith99]

I think with Jupiters, copy variation is the main factor. I've owned 2 M39 alu J9s and they seemed about the same. i hope my new LTM does as well.

[Orio]

Conclusion is that unless one has tested multiple copies of this lens, it's impossible to say anything conclusive.
My experience is that my aluminium copy is the sharpest and in general one of the sharpest lens I have wide open, while the MC version abuntantly flares wide open, and I am convinced that this is by design (i.e. they wanted it to do that).

[aoleg]

[BRunner]

I owned and tested 5 different copies. 3 black, 1 silver and one new latter finish black. The only conclusion is, that it's lottery. Doesn't matter if the lens is silver or black, if it is newer or older, you just need to be lucky to get good copy.
I kept the latter black version, because it's reasonably sharp and has best color accuracy of the 5 and the silver, because is comparably sharp and it's silver...I do like shiny things, you know...