Zeiss 85/1.4 - Is it hard to focus?

[rickd]

I'm coming late to the discussion, but thought I'd throw in my $0.02. I've had the 85/1.4 seemingly forever, having bought mine not long it after getting my RTS. There's no question that with a DOF thickness not unlike that of a piece of typing paper when shooting wide open up close, getting, for ex&le, an eye *just so* can be a challenge. But I've always found the lens up to snuff as long as I've handled it correctly. (As has been well pointed out, the laws of optics never take a day off no matter whose name is on the lens.) While I generally don't shoot it wide open, I'm certainly not afraid to do so. Also, the ability to throw distracting fore- or background objects out of focus also shouldn't be overlooked. The 85/1.4 is superlative for this, making it a great landscape lens.

What's perhaps not been emphasized enough is the dramatic "pop" of a subject coming into focus through the viewfinder using this lens. I find it quite helpful in composing a shot, in bright light or dim. (Getting a proper lens shade is important, that's a big front element and eliminating flare shooting wide open can be critical. If you go the Contax route you need to buy both a hood and a step-up ring.)

I too prefer shooting with a cross-hatch matte screen. Don't really know why, I just do, finding split-screens more bother than they're generally worth.

The only lens of this approximate length I've personally seen routinely out-perform the 85/1.4 is the 90/2.8 Sonnar for the G, truly a lens to be reckoned with. But that's another topic entirely.

--Rick

 

[edmond]

It is just that some other comments stated that 2.8/85 wide open and stepped down sharpness is not as good as 1.4/85 at the same aperture. If I recalled correctly, one stated that it was not as sharp as his 1.4/50. Without another lens for side by side comparison, you should be happy with either one.

On color reproduction, I did not see any comparison for the two 85mm. I haven¡¦t carried out particular test to see which one produce better colour tone. Different aperture settings would also cause a change in colour tone.

Information from Japan web site indicates that the earlier 2.8/85 has both J and G versions in the market before 1987 and then only re-launched and manufactured in Germany in around 1998 together with the introduction of ARIA.

 

[afranklin]

> Has nobody heard of using the depth of field prefeview to control=20 > what you=20

You simply can't do critical focus determination with DOF prefiew=2E

 

[davidfung]

Edmond, just looking at the Zeiss MTF for the two lenses. Comparing at say 5.6, the 1.4 has a lower resolution than the 2.8. The 2.8 has an almost flat response of 40 lpmm curves, at around 70%. The 1.4 seems to have 60% in the centre, rising to almost 80% then ending at 70%. To me, it seems like the 1.4 is sharper, but in the 10 - 15mm zone. And from the MTF, the 2.8 seems to have a better bokeh, due to both sagittal and tangential MTF very close together at 2.8. Anyway... hard to really talk about it, without having used the lenses...

 

[mike_nunan]

Hi David,

I'm not sure you can rely upon that rule regarding bokeh. It may be the case that lenses with badly separated sagittal and tangential curves have bad bokeh, but I would be very surprised if all lenses with closely matched curves have good bokeh. I suspect this rule mentioned on photodo arose from an assumption of some kind, and I would not trust it unless there was better substantiation of it. That said, the 1.4 lens has fantastic bokeh (IMO) -- which is not to say that the 2.8 might not be even better, as I haven't used one.

Austin, I'll keep you posted on the 85mm comparison test. I'm planning a bunch of tests in the near future anyway, as I'm borrowing a small Leica M system with a view to seeing whether it will give me the wide-open performance that the Zeiss gear has (so far) failed to deliver. I was going to compare against the Canon glass just interest's sake, so I can easily shoot a few tests with the 85 while I'm about it. No sweat re the DOF discussion.

Take care,

-= mike =-

 

[davidfung]

Mike, thanks for your thoughts. I am not sure that the comments about bokeh came from photodo. I have read the articles there, but am sure that it also comes from different sources. I will look into that. But the correlation between sagittal and tangential does have a bearing on astigmatism, am I right to confirm?

 

[mike_nunan]

Just had to check, but astigmatism leads to a point object's image being smeared or defocussed laterally in one specific direction. That means that the sagittal and tangential MTF would both be affected if you averaged out multiple measurements at evenly spaced angles around the lens axis. I think coma is the aberration you were thinking of, as it is the only one (AFAIA) that affects sagittal and tangential sharpness separately.

The following well-researched article by Harold Merklinger seems to indicate that spherical aberation may be the main influence:

http://www.trenholm.org/hmmerk/ATVB.pdf

Even that is not a fully conclusive explanation, and I would recommend letting your own eyes be the final arbitrator when it comes to any purchasing decisions, rather than relying upon theory.

HTH

-= mike =-

PS. I've a feeling that the comment about the MTF curves might have come from Canon's Lens Work book, rather than photodo.

 

[edmond]

I found that the MTF would tell the lens is not a good lens if the 40 lpmm initial % (i.e. centre reading) already get below 60% at f5.6. For Zeiss MTF with 40 lpmm initial reading near or above 70%, it would be a very good lens.

However, for those with initial % above 60%, the sharpness, correction of aberration or resolving power etc, still cannot be interpreted from the graph. For ex&le, comparing Hasseblad 5.6/Sa250 and 5.6/Sa350 MTF, it could not tell the centre 250 line per mm resolution or their superachormatic characters based on the reading.

Comparing my 2.8/85 and 1.4/85, I did not notice any major difference corresponding with the trend of the 2 MTFs. But as my test photos are only for buildings at around 120m away and not for a resolving line chart, I cannot tell the critical difference in the resolving power for my two 85mm. In practice, the individual variation in lens quality for different batches will give a different result as compare to the s&le MTF.

 

[davidfung]

Thanks for all your input. I have recently purchased a 8.5 1.4 (german) from eBay, and awaiting its arrival. Thanks again for all your input.

 

[ltsdnce]

I recently purchased a 85/1.4 and I find it very easy to focus. As Rick said, it "pops" into focus. I find it a little easier to focus than my 50/1.4 and alot easier than the 28-85. I have the all matte screen (switched from the split prism ) and this helps quite a bit in my opinion.
Susan