Huss
Veteran
The Zeiss Sonnar ZM 50 1.5 is notorious for focus shift and that is way more expensive than 7A lenses.
7Artisans lenses - no such thing as a free lunch
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james.liam
Well-known
In a re-education camp.
That's the nature of the Sonnar design and unavoidable. Take the Nikkor 50/1.4 LTM; focus is optimized for ƒ/1.4 shifting steadily as you stop down. In the case of the 1,5/50 ZM, Zeiss optimized focus for ƒ/2,8 where it's spot-on. Buy it new and they will re-adjust it gratis, optimizing focus for ƒ/1,5 if that's your preference.
BernardL
Well-known
zuiko85
Veteran
How would any lens with noticeable focus shift be useable on a RF? Perhaps if the amount of focus shift was so small that it was less than the DoF increase from stopping down?
Seems that lens would work best on a TTL type viewfinder camera.
Seems that lens would work best on a TTL type viewfinder camera.
Huss
Veteran
Incorrect. The rf’s in all my M’s are correctly calibrated. And yet I have two lenses that are not spot on. My ZM 50 1.5 front focuses, while my CV 35 1.2 v2 back focuses. I take this into account when I use them but I would absolutely love it if I can bring them into correct focus calibration the way I can do with 7A lenses.
dotur
od karnevala
Sorry Huss, you are right. I stand corrected. The main issue are not the lenses, but that primitive and obsolete tool we use for focusing them, the rangefinder. 🙂
Huss
Veteran
rscheffler
Well-known
With a lens like the Zeiss 50/1.5 Sonnar, as james.liam above mentioned, the manufacturer traditionally calibrated the optimum RF focusing a couple stops down from wide open. This meant that at f/2 the lens slightly front focused, but might still be reasonably within DOF (and on film, maybe not so noticeable), while at f/4 it would be slightly back focused, but the increased DOF at f/4 would hopefully cover much of that error. Shooting wide open would have the greatest focus error, but the lens was already pretty glowy and the SA would mask some of this. Again, on film it was likely less noticeable. My understanding is now the ZM50/1.5 is RF calibrated for wide open use, given this is now the popular way to use the lens on digital. To compensate for focus shift, one would have to intentionally guesstimate intentional front focus when shooting at f/2, 2.8 and f/4 before DOF masks the shift.
I also have the 7A 50/1.1 and fine-tuned the RF cam for correct RF focus with my camera at f/1.4, the point at which it sharpens up a bit yet still has nice SA glow. TBH, I have not checked infinity. I primarily use the lens at nearer distances as a character lens. It takes stopping down to f/11-16 to really bring up the edges for more technical applications. Instead I rather use a more capable design for such applications (i.e. ZM50/2 or 50 Lux ASPH).
rcubed
Canadian
...........
Huss
Veteran
Does it focus past infinity?
rcubed
Canadian
Surprisingly no. Its the best calibrated out of the box of all my 7a lenses
Huss
Veteran
Ricoh
Well-known
When checking and adjusting the 7A lenses do you use the chart supplied with the lens, or one of these https://www.wexphotovideo.com/datac...MIpL2t9sLo6gIVyp13Ch1jKAlUEAQYASABEgIG9PD_BwE
Huss
Veteran
Both. And also pointing at other static targets that have depth to them. I use a tripod when I do this so my position does not move.
I actually found that using regular static targets around the house to be just as effective. The SpyderLENSCAL was much more useful when I was dialing in AF lenses on my D850.
Ricoh
Well-known
Thanks Huss, based on what you’ve said I’ll stick with the chart and see if I can improvise with stuff around the house.
Huss
Veteran
7A 50 1.1 @ 1.1 on an M240.
Focused optically via RF, not EVF.
Focused optically via RF, not EVF.
Forest_rain
Well-known
For the money, you could get a Voigtlander Nokton 40mm 1.4...but the pictures from the 7artisans look pretty good.
The 3rd party lenses like 7artisans have not been well reviewed for DSLRs. Well, they have the "pretty good, but not the best, good for the price" type of recommendation.
I'd be interested in a Voigtlander comparison.
The 3rd party lenses like 7artisans have not been well reviewed for DSLRs. Well, they have the "pretty good, but not the best, good for the price" type of recommendation.
I'd be interested in a Voigtlander comparison.
Ste_S
Well-known
Likewise. I have a Zeiss 35 2.8 which I love, however I'll be looking for something faster for the winter months. For the price I guess it will be between a Voigtlander and 7artisans, with Voigtlander probably winning as I don't have a digital M to calibrate the lens
phojsu
Member
I'm late to this discussion and will add my two cents. The Sonnar 50/1.5 has been known for focus shift when closing down ever since the originals were introduced, as well as all true clones. My ZM Sonnar 50/1.5 is only used wide open or stopped-down to at least f/4.0, this when on one of my Leicas. I've used it on mirrorless, first the Sony A7-2 and now the Canon R, using focus peaking there is no issue at any aperture.
I recently got the 7Artisans 75mm f/1.25 and out of the box the focus was dead on wide open within the confines of my living room. Additional testing will commence now that I have a UV filter and vented hood. If it doesn't satisfy on the Leicas it may be relegated to mirrorless duty.
In the same spending spree I also acquired the CV Nokton 35mm f/1.2 (v III ?) to replace the larger example (v 1) I've used since 2009. A concave front element has always surprised me, but once a UV filter and hood are in place, the front element is no longer a visual issue. I'm expecting further great things with this lens as a complement to, rather than a replacement for my 35 Summicron IV. The CV Nokton will likely only get used wide open down to f/2.0 where the smaller Summicron will be the obvious choice.
Bolo Kukus
en vacances, en permanence
A few friends of mine have these lenses. I've inspected them and even played with a few.
My summary - caveat emptor.
Inexpensive, yes. Anything else, well. You pays your $$ and you takes your chances. One of the six or so I looked at produced okay (to my taste, 6/10) results. The others - I will only say, their owners were my good friends so I had to be polite.
As I see it, if you have To dismantle the damn things to get the infinity focus right - shouldn't that be done at the factory before the lenses are released to be sold??
Voigtlander lenses cost more, but oh gosh, the quality...
My summary - caveat emptor.
Inexpensive, yes. Anything else, well. You pays your $$ and you takes your chances. One of the six or so I looked at produced okay (to my taste, 6/10) results. The others - I will only say, their owners were my good friends so I had to be polite.
As I see it, if you have To dismantle the damn things to get the infinity focus right - shouldn't that be done at the factory before the lenses are released to be sold??
Voigtlander lenses cost more, but oh gosh, the quality...
