I know, it's not fair. Their focal lengths are substantially different but many shooters are trying to decide between these two lenses. I compared both against each other today and learned a lot from it.
My Batis 18/2.8 copy is well-centered and so is my Loxia 21. Although their MTF graphs suggest the Batis is more flat field, I was surprised to see they actually have similar inwards field curvature. Perhaps the Loxia has slightly more but I would say it's pretty comparable.
I will start posting 1:1 crops showing their best extreme corners ignoring field curvature (focused on infinity towards the edges). Later on I will post crops demonstrating they have similar field curvature.
So, here are the best corners from both lenses at all apertures. I will update this thread with more tests.
Lightroom sharpening: 45, 0.7, 25,0. No lens profiles applied in post.
1) It's a sharp lens straight out of f/2.8 from center to corners. Sweet spot is f/5.6 for best center/corners.
2) It has noticeable field curvature at infinity (inwards)
3) It's not as sharp towards the corners when comparing to the Loxia 21/2.8. However, it's not really fair to compare it to the Loxia because of the wider focal length. (will post crops later)
4) There is slightly less contrast towards the edges when compared to the Loxia 21.
5) My copy is well-centered and that could mean good news as far as QC goes.
I tested them at two different lighting conditions to make sure the results were consistent and they were.
BTW: Here is the difference in field of view between the two lenses.
Here is a demonstration of how field curvature affects both lenses.
The extreme crops on my first post, were focused on the corners at infinity (best corners). However the center area lost resolution on images from both lenses.
Below are the same extreme corner area but this time from images focused on the center of the image field (infinity focus)
Notice how crops from both lenses look softer towards the edges when focused on the center at infinity:
Not thrilled about the loss of contrast on the Batis as its going out towards the corners. Regardless of focal length difference I don't find it let's say ideal landscape lens in a sense. Obviously this can be worked on in post. But I guess we should remember there is a big difference in focal length and we all know it's very difficult to design extreme wides. So maybe given the focal length it's a wash. Let's try to remember the VC 15 as that's even wider by 3mm focal length. I think still a good showing for the Batis but for me at least and this is me as I'm a weirdo on this stuff . The Batis is not kicking the 21 to the curb either. Again it's not a easy task to be given up a perfect copy of the 21.
As far as the 16-35 from what we learned the Loxia 21 is better and the Batis 18 should follow as well.
It's from the same image crops above (showing softer extreme edges). Because it was focused on the center, it demonstrates the best center crops for both lenses. They are pretty similar here with a slight edge for the Loxia.
The other thing I'm looking at is wide open and here the Loxia looks much better to my eyes at least. To me the 21 looks to have more zippedy do da. Lol
Also it's wider for sure but see the Windows tilting more towards the corners on the Batis. Obviously the effect of a wider lens
This thread is a little confusing but I wanted to demonstrate how the effects of field curvature can change the results. One needs to be very careful when focusing these lenses. It's not enough to set the focusing ring to infinity (Or use the Batis display) and shoot away...
GMPhotography wrote:
The other thing I'm looking at is wide open and here the Loxia looks much better to my eyes at least. To me the 21 looks to have more zippedy do da. Lol
Also it's wider for sure but see the Windows tilting more towards the corners on the Batis. Obviously the effect of a wider lens
The Loxia 21 definitely has more "zippedy do da". Even in the corner crops, the Loxia has a more 3-dimensional look with greater depth between different elements in the image compared to the Batis18.
Fred Miranda wrote:
This thread is a little confusing but I wanted to demonstrate how the effects of field curvature can change the results. One needs to be very careful when focusing these lenses. It's not enough to set the focusing ring to infinity (Or use the Batis display) and shoot away...
I will post the softer centers next (from the images focused towards the edge at infinity).
This is the key reason I prefer MF over AF for wides. Setting precise focus with fly-by-wire requires more faffing about. With MF, once you know your focus set point for a given condition, you can swiftly rotate the focus ring to the required position (e.g. a smidge back from the hard stop).
lambers wrote:
This is the key reason I prefer MF over AF for wides. Setting precise focus with fly-by-wire requires more faffing about. With MF, once you know your focus set point for a given condition, you can swiftly rotate the focus ring to the required position (e.g. a smidge back from the hard stop).
I trust Fred's testing quite a lot so here is my thoughts the Batis is more the reportage lens and the Loxia is more for hard core landscape folks as it brings better precision in focusing. Not saying you can't use either one of them in many different situations but the overall feel to me is this and maybe exactly what Zeiss is making the Batis line for. There damn good no question about it they just maybe belong to different types of shooters. Now maybe I'm bias a little too as I'm a old school manual focus shooter.
Yea basically all your doing is cropping it has no effect on anything else.
Fred Miranda wrote:
If you crop the B18 to match the L21 field of view, you will lose resolution and therefore the results will be worse for the Batis 18.
Focusing the Loxia at infinity is fairly easy. At the hard stop you have the best edges in detriment of minor softness in the center of the image field. A tiny little tad rotation from the hard stop will be the best compromise and the image looks strong from the center to edge. It's interesting how a minimal rotation makes so much difference. (center and edges)
For the Batis 18 it's a little more challenging to get best focus at infinity. When focusing on the edges or center, the display shows the infinity mark.
When you first see the infinity symbol by moving the ring counter-wise, that is the best corner focus. Then moving it slightly counter-clockwise makes best center. The compromise is hard to know...Perhaps focusing on the mid-field is the way to go for this lens.
I would whole heartedly agree. I think the Batis has some distinct advantages for street use being autofocus in the first place. But for the most critical landscape usage indeed I suspect the Loxia will inch out the last bit of sharpness and detail at the extremes.
GMPhotography wrote:
I trust Fred's testing quite a lot so here is my thoughts the Batis is more the reportage lens and the Loxia is more for hard core landscape folks as it brings better precision in focusing. Not saying you can't use either one of them in many different situations but the overall feel to me is this and maybe exactly what Zeiss is making the Batis line for. There damn good no question about it they just maybe belong to different types of shooters. Now maybe I'm bias a little too as I'm a old school manual focus shooter.
These tests were done carefully (and repeated) because I know many shooters are choosing between them. However, I don't like to make generalizations because I only tested one copy of the Batis 18/2.8. It seems to be a good copy and it's not decentered but we never know if there are other copies performing better or worse. Only Roger tests will show.
I went through a couple of Loxia 21's before it was replaced by Zeiss themselves. I know my Loxia 21 is a good copy because I was able to compare a few of them.
Personally I think the Batis 18/2.8 is excellent and a great choice for Sony shooters. Is the Loxia even better?
Based on my copies, I would say yes but that's a totally different focal length.
I know it's a battle between 15 up to my GM 24-70 . What would work best for me . I can't do all three 15,18,21. So that's what I face. Others may not have to deal with this but are facing QC issues lately notable the VC 15 and the Loxia 21 so anything is possibly. It certainly is a very nice lens and it's going to be loved by many. Glad it's out now as we get another lens to consider. Thanks Fred for your testing samples.
