Thanks, IzelPhotograph, I could reproduce your findings, and did a slighly differnt testing afterwards.
Using exposure lock, setting aperture to f2, constant ISO and leaving shutter speed as the only variable. Using this setting, I can defently measure a small light loss between focus distances above 0.7 and below infinity. But the light loss is rather small, leading to shutter times of, for example, 1/40 at 1.5 meter instead of 1/50 or 1/60 at infinty. This light loss might be so small that it doee not affect the values in the exposure metering in your video (since this might need a bigger change to measure 1/3 stop of a difference).
So, no big deal, the Batis 40 is more like a f2.2 Lens at working distances between 1 and 2 meter. This might be okay, but in comparison to the (way smaller) 35mm f 2.8 lens, it reduces the gain of light to less than one stop.
Clemens Re wrote:
Thanks, IzelPhotograph, I could reproduce your findings, and did a slighly differnt testing afterwards.
Using exposure lock, setting aperture to f2, constant ISO and leaving shutter speed as the only variable. Using this setting, I can defently measure a small light loss between focus distances above 0.7 and below infinity. But the light loss is rather small, leading to shutter times of, for example, 1/40 at 1.5 meter instead of 1/50 or 1/60 at infinty. This light loss might be so small that it doee not affect the values in the exposure metering in your video (since this might need a bigger change to measure 1/3 stop of a difference).
So, no big deal, the Batis 40 is more like a f2.2 Lens at working distances between 1 and 2 meter. This might be okay, but in comparison to the (way smaller) 35mm f 2.8 lens, it reduces the gain of light to less than one stop....Show more →
In terms of light loss it is so small that the camera doesn't recognise it (exposure comp doesn't pickup on it) and as such, the exposure is effectively the same from what I've found when shooting with it. That's why I said I never seen any stopping down as there was never a change to exposure until I got to 0.7m. What I don't want people to think is that you're going to see a change in exposure settings between 1-3 meters compared to infinity (as demonstrated in the video clip).
I still think it would be interesting to see exactly what it is up to. I think they need to be honest about it and tell us. That said such small differences in light / DoF shouldn't be the main concern. If you're going to shoot a lot of portrait / family shots with this lens then the Eye AF would be my concern and not the aperture.
I have shot with the 35 f/2.8 but never felt the love for it. I like to get up close to a lot of subjects so the 35cm used to come into play and the separation was not as great compared to the 40mm. The 35 f/2.8 is a solid performer but it never made me want to shoot with it. Functional is the word that springs to mind but I felt it lacked character, especially compared to the Batis range. That is however a very subjective point and will vary from person to person.
IzelPhotograph wrote:
In terms of light loss it is so small that the camera doesn't recognise it (exposure comp doesn't pickup on it) and as such, the exposure is effectively the same from what I've found when shooting with it. That's why I said I never seen any stopping down as there was never a change to exposure until I got to 0.7m. What I don't want people to think is that you're going to see a change in exposure settings between 1-3 meters compared to infinity (as demonstrated in the video clip).
I still think it would be interesting to see exactly what it is up to. I think they need to be honest about it and tell us. That said such small differences in light / DoF shouldn't be the main concern. If you're going to shoot a lot of portrait / family shots with this lens then the Eye AF would be my concern and not the aperture.
I have shot with the 35 f/2.8 but never felt the love for it. I like to get up close to a lot of subjects so the 35cm used to come into play and the separation was not as great compared to the 40mm. The 35 f/2.8 is a solid performer but it never made me want to shoot with it. Functional is the word that springs to mind but I felt it lacked character, especially compared to the Batis range. That is however a very subjective point and will vary from person to person.
Izel: I believe Clemens is saying that the camera’s exposure metering does not show a decrease in exposure levels because the exposure (light) meter’s smallest increment is .3 EV (or 1/3 of a stop roughly). Thus, at distances greater than 1 meter, let’s say 2 meters where the aperture is slightly closed at f2, the exposure is effected and light is lost, but its an amount less than the exposure meter can display (less than 1/3 of a stop). Clemens’ shutter speed tests correlates the light loss to the B40’s systematic stopping down.
Newtographer504 wrote:
Izel: I believe Clemens is saying that the camera’s exposure metering does not show a decrease in exposure levels because the exposure (light) meter’s smallest increment is .3 EV (or 1/3 of a stop roughly). Thus, at distances greater than 1 meter, let’s say 2 meters where the aperture is slightly closed at f2, the exposure is effected and light is lost, but its an amount less than the exposure meter can display (less than 1/3 of a stop). Clemens’ shutter speed tests correlates the light loss to the B40’s systematic stopping down.
I appreciate that but if it is that small as to be barely picked up by the camera then I'm not about to lose any sleep over it. I guess that is where I'll draw the line on this discussion as there are plenty of other factors that would have a greater impact on image making.
I took the B40 out for the day with the wife and baby yesterday and enjoyed it. Not keeping it, but it impressed me handling bright sun and fast focusing. In bright light I was surprised how fast the thing picked up subjects, without hunting or going through the entire depth of focus before catching an object. Here’s a couple of shots:
Yes, that's exactly what I was trying to add. But the loss of light at distances above 1 meter and below infitiy is of course only maginal and should therefore hardly be noticeable in reality.
However, for all those who are really disturbed by the not completely round Bokeh circles (that's not the case with me), the slightly closed aperture above one meter might be annoying. With point light sources in the background, a slight nonagonal shape remains even with shots between 1 and 3 meters away. But this is hardly noticeable, as the slightly closed aperture already has an almost round shape.
With regard to the comparison to the FE 35 2.8 I have to correct myself a bit. With a somewhat demanding background (e.g. with branches) the bokeh of the Batis 40 is noticeably smoother. But of course the FE 35 2.8 is not the reference in this area either.
My Batis 40mm arrived yesterday and after preliminary tests, my copy only have a slight issue in magnified view AF from a close distance. If the distance is >1 meter, magnified view AF works just fine. I think the need to have magnified view AF is greater for objects that are a bit far from the lens, and not really relevant for close objects, therefore for me, it’s something that I can live with. As for the Eye-AF, so far no issues, even focusing at close distances.
I also noticed the downside of being automatically stopped down to f4.0 for close focusing is obviously the ISO will need to be cranked up in low light situation. The “nonagonal” bokeh is noticeable, but the bokeh character is really smooth for an f4.0. Overall, I’m really happy with its performance.
ZEISS answered on my comment (youtube ad for zeiss 40 f2)
Thanks for your inquiry. We are sorry to hear that you have troubles with the eye AF function. As we take the feedback from our customers very seriously, we are intensively evaluating the issue to reproduce this effect. Please understand that the evaluation may take some time. You may rest assured that we do our best to solve any kind of issues that might appear in combination with our photo lenses. We will get back to you as soon as possible. Kind regards, Your ZEISS Camera Lenses Team
Well, its a hard decision to make. I am generally very happy with mine and it is seems to be doing OK with Eye-AF but these days I am questioning every shot I don't nail since I see misses with the 50mm f/1.4 ZA as well.
So I've had it for three weeks and I have to decide to send it back or decide to register it to get the extended warranty since both have to happen within the first four weeks of ownership.
I guess I am going to take the risk and keep it.
So if there is an issue, that Zeiss is willing to admit, will there be a recall? Can the firmware of a Batis lens be upgraded by the user? I own the other four Batis lenses and have yet to see Zeiss offer up any firmware upgrades to them so I don't even know if that is possible. Does anyone know? Or would there be a recall?
I guess I am going to see if I can get an answer to that question.
swldstn wrote:
Well, its a hard decision to make. I am generally very happy with mine and it is seems to be doing OK with Eye-AF but these days I am questioning every shot I don't nail since I see misses with the 50mm f/1.4 ZA as well.
So I've had it for three weeks and I have to decide to send it back or decide to register it to get the extended warranty since both have to happen within the first four weeks of ownership.
I guess I am going to take the risk and keep it.
So if there is an issue, that Zeiss is willing to admit, will there be a recall? Can the firmware of a Batis lens be upgraded by the user? I own the other four Batis lenses and have yet to see Zeiss offer up any firmware upgrades to them so I don't even know if that is possible. Does anyone know? Or would there be a recall?
Hopefully, Zeiss has designed the Batis lens electronics different than the Touit series to hopefully allow users to update firmware themselves. The strange thing is that the Touit X-mount lenses are user upgradable but not the E-mount Touit lenses.
If Batis lenses are not user upgradeable, I will seriously debate if I should buy more Zeiss Batis lenses at all and just stick with user upgradeable brand lenses. Sending in a lens for firmware updates is just so 2010.
bjornthun wrote:
Hopefully, Zeiss has designed the Batis lens electronics different than the Touit series to hopefully allow users to update firmware themselves. The strange thing is that the Touit X-mount lenses are user upgradable but not the E-mount Touit lenses.
If Batis lenses are not user upgradeable, I will seriously debate if I should buy more Zeiss Batis lenses at all and just stick with user upgradeable brand lenses. Sending in a lens for firmware updates is just so 2010.
I really Hope you’re right! The thing is that not a single Batis required any firmare upgrade, so we’ll see! Fingers crossed
I really Hope you’re right! The thing is that not a single Batis required any firmware upgrade, so we’ll see! Fingers crossed
Key question is did they not require any updates or did Zeiss just not make an effort because all the lenses would have to be sent in and they are ill prepared to handle it? If that turns out to be true then I would start to question if buying their lenses is the smartest thing to do in an eco-system where firmware upgrades to correct issue has become a must have to do business.
Would like to have this answered by some Zeiss ambassador. I've looked up a few names and they should help us find out.
Ok, I've been contact with Zeiss and I've got some news regarding the Batis 2/40 CF situation:
EYE-AF
Zeiss is intensively evaluating the issue. The evaluation may take some time, but Zeiss is working on it and doing their best to solve any issues that appear in relation to camera/lens operability.
REDUCTION OF APERTURE AT CLOSE DISTANCES
The lens automatically stops down when working near the minimum focusing distance. This ensures the high contrast and resolution across the entire focus range. This might, sometimes, result a visible nonagon (not perfectly round bokeh ball) within a blurred background. Zeiss is currently developing a software update that will allow user to work within a larger focus range with a wide-open aperture. The update will be available to download for free from the ZEISS website in early 2019. Zeiss will notify all registered customers via email.
So, all in all, Zeiss is still working with the Eye-AF issue. Nothing new here, except it might take some time to solve it. But they are working on it.
However, there's a new piece of information about the aperture automatically closing when working at close distances: Zeiss is changing this behaviour. Personally, I'm surprised to hear this as I never experienced this as a problem myself. Regarding what I heard, it sounds to me that Zeiss will not remove the automatic aperture behavior totally, but they will adjust it so that it will kick in later or less strong or something like that.
Thanks for the update, Toni! Hopefully the Sony/Zeiss relationship and contractual agreement is strong enough that Zeiss gets support from Sony and if the body needs a firmware update to support the lens we get it. Panasonic and Olympus had such a relationship and occasionally issued body firmware updates to resolve issues with their respective m4/3 partner’s lenses. And this suggests the Batis lenses are user firmware upgradeable. I really want to buy this lens!
Such a bummer the eye AF issue. I definitely have the problem with my a9 and Batis 40mm, which puts a damper on my xmas photo plans. I'll just have to be diligent when focusing, but for $1300 I shouldn't have to make compromises.
Had an interesting results yesterday. I was shooting with a flash yesterday at a private dinner party I was attending and wanted to try out the 40mm in that environment. I took other lenses but I decided to see if I could get this to work and focus accurately since most of the pictures are of people and they need to be sharp.
Well I ended up getting great results IMHO. Most shots had great focus even though I shot most at f/2, f/2.8 and f/4. The stopped down ones where when there were multiple people in the shot and the deeper depth of field was really needed. With only one person mostly use f/2 or f/2.8
So I am wondering if the addition of the flash caused the focus system, with Eye-AF enabled, to behave differently. Without flash, for my copy, it appears I'm getting good results in general.
