Beni wrote:
I'll take it a step further, is there anything to beat a WLF for studio work? Actually to be honest using the rear screen on the A7/r comes very close but again there is the problem of the focusing stopped down. I love shooting with the screen angled to be a WLF.
I'll take it a step further still. Nothing beats a WLF for most of the work I like to do: portraits, still life, and unobtrusive street shooting. The camera system I most enjoyed using (and which yielded many of my favorite pictures) was a Hasselblad 500 C/M with just 60mm and 100mm lenses. I had a prism viewfinder but rarely used it. Mirrorless cameras with, as you say, "the screen angled to be a WLF" offer something very close to the experience of shooting with either an SLR (Hasselblad, Bronica) or TLR (Rolleiflex, Mamiya C-Series).
As for the problem of focusing stopped down, does this mostly occur nowadays when using certain Leica M/LTM lenses on a Leica M body or with completely manual (i.e. legacy) lenses on mirrorless bodies? And does it arise because we wish to gauge the zone of focus or because we want to avoid focus shift?
I don't recall frequently using the stop-down lever/button on my film cameras to check the zone of focus because the OVF became so dark that it was difficult to see what was actually in focus. Most of the time I used the DOF scale on the lens and stopped down an extra stop for safety.
For twenty years I shot on film without ever hearing about focus shift even though I obsessively read camera magazines throughout that entire period. It must have existed in both SLR and RF lenses. Yet during that time I used a Leica M2 with lenses ranging from 21mm to 90mm while making pictures that seemed (at the time) to be adequately sharp. Did film mask the effects of focus shift, given that it only seems to have become a concern since the advent of high resolution digital cameras?
Veering back towards the thread topic, I realize that the lack of auto-aperture makes it less likely that I'll purchase any of the Loxia lenses. I was hoping for some small, high-quality MF E-mount lenses (with minimal focus shift) which would free me from either having to focus wide-open before stopping down or focusing stopped-down and trusting that I'd hit the focus point correctly.
Other than the smaller size (and some incremental improvements in quality) I don't see how the Loxia lenses offer a significant improvement over the Canon FD, Contax C/Y, Hexanon AR, Leica R, Minolta MC/MD, and Olympus OM lenses I already own. Loxia 35/2 or Contax C/Y 35/1.4? I'll happily suffer the extra size and weight of the Contax lens and delight in its marvellous rendering.
genji, you've precisely summed up the feelings I was just about to post on the subject!
I appreciate the desire to create a fully manual lens, but electro-mechanical apertures have been produced in the past to offer the best of both worlds (I believe some Mamiya lenses had them).
The ability to focus wide open and have the lens stop down to shoot would be a huge benefit of the Loxia series, for reasons stated in a previous post, but to summarise, limited resolution in the viewfinder makes the DOF seem deeper than it is, therefor focusing a few stops wider than the shooting aperture balances this effect and guarantees what looks sharp in the EVF will look sharp in the image.
Without this the Loxia lenses offer little compared to the alternatives. If you want a very sharp (but clinical) normal lens then there is the FE 1.8/55, if you want character then there are many many options that offer the full manual experience, at much more attractive price points from $10 50mm f/1.8s up.
Essentially the advantage comes down to:
1. EXIF information. Which is a nice-to-have, could become more important over time as my lens collection increases, but by then there may be better native offerings.
2. No faffing with adapters. In a wide lens the difficulty finding a perfectly straight adapter would push me toward a native offering from Zeiss or otherwise. At 35mm and 50mm it doesn't bother me.
3. Weather sealing. Not critical given what I intend to shoot.
genji wrote:
Did film mask the effects of focus shift, given that it only seems to have become a concern since the advent of high resolution digital cameras?
Most likely. Film emulsions are thicker (and less angle dependent) than digital sensors, making them a lot more forgiving (as long as the film is held flat) but generally also less critically sharp than digital sensors can be.
Was playing with my Super Tak 50mm today, it has a little switch on the side of the lens, you can use it to automatically switch to wide open for focusing then back to stopped down for the shot. Not what it was designed to do but it's actually a rather nice little workaround. Wish my other lenses had it now I wonder if I might trade my K-M for the Takumar which is weirdly considerably more expensive. Can't see one on ebay for under $400+ with haze or other optical issues. Weird.
Matt Grum wrote:
Without this the Loxia lenses offer little compared to the alternatives. If you want a very sharp (but clinical) normal lens then there is the FE 1.8/55, if you want character then there are many many options that offer the full manual experience, at much more attractive price points from $10 50mm f/1.8s up.
Essentially the advantage comes down to:
1. EXIF information. Which is a nice-to-have, could become more important over time as my lens collection increases, but by then there may be better native offerings.
2. No faffing with adapters. In a wide lens the difficulty finding a perfectly straight adapter would push me toward a native offering from Zeiss or otherwise. At 35mm and 50mm it doesn't bother me.
3. Weather sealing. Not critical given what I intend to shoot....Show more →
Matt, I forgot about the EXIF info and that is certainly a desirable feature. I've chosen to go with Novoflex adapters, which have worked well for me with wider lenses but most of the time I use a 35/55/85 trio. I have about a dozen 55mm lenses, including the FE 55/1.8 and a Canon FD 55/1.2 Aspherical, but one of my favorites is a $15 Industar 61 55/2.8. As you say, there is no shortage of options if one is looking for a character lens.
genji wrote:
Matt, I forgot about the EXIF info and that is certainly a desirable feature.
It's something that could be resolved by the camera body if it allowed you to program a series of lenses and select the current lens being used. It could also allow you to set the aperture on the camera body in tandem with a physical aperture so that all shooting parameters were correctly recorded.
But there would be little motivation for Sony to put the work in to do this with the only benefit being for people using non-Sony (or non-Zeiss, with whom Sony have an affiliation) lenses!
It's not a problem for me now as the lenses I'm currently using are easy to distinguish and I can usually tell what aperture I would have used in a certain situation.
But with a larger lens collection I can see it being an issue.
Genji--the most fun I ever had doing photography was with a Hass 500 c/m and a couple of lenses.
The A7r with the FE 55 gets me close to that. And my old back greatly appreciates the lightness of the of A7r. I'd like to have a wide lensr. Perhaps the forthcoming 16-35mm will be a winner.
Matt Grum wrote:
It's something that could be resolved by the camera body if it allowed you to program a series of lenses and select the current lens being used. It could also allow you to set the aperture on the camera body in tandem with a physical aperture so that all shooting parameters were correctly recorded.
But there would be little motivation for Sony to put the work in to do this with the only benefit being for people using non-Sony (or non-Zeiss, with whom Sony have an affiliation) lenses!
It's not a problem for me now as the lenses I'm currently using are easy to distinguish and I can usually tell what aperture I would have used in a certain situation.
But with a larger lens collection I can see it being an issue....Show more →
When I was shooting Nikon, the D300 and D700 allowed one to program a series of lenses -- it was a great feature.
I have a "larger lens collection" and I deal with the problem by storing a set of lens descriptions in my smartphone and taking an identifying frame whenever I switch lenses. I then add the lens info as keywords in Photo Mechanic. A minor hassle, to be sure, but I like to keep track of the lens I've used for a particular picture.
Abstraction wrote:
Genji--the most fun I ever had doing photography was with a Hass 500 c/m and a couple of lenses.
The A7r with the FE 55 gets me close to that. And my old back greatly appreciates the lightness of the of A7r. I'd like to have a wide lensr. Perhaps the forthcoming 16-35mm will be a winner.
Agreed! I'm pretty happy with a 35 + 55 combo on the A7/A7r -- with either FE lenses when I need AF or legacy lenses when I don't.
Matt Grum wrote:
It's something that could be resolved by the camera body if it allowed you to program a series of lenses and select the current lens being used. It could also allow you to set the aperture on the camera body in tandem with a physical aperture so that all shooting parameters were correctly recorded.
But there would be little motivation for Sony to put the work in to do this with the only benefit being for people using non-Sony (or non-Zeiss, with whom Sony have an affiliation) lenses!
It's not a problem for me now as the lenses I'm currently using are easy to distinguish and I can usually tell what aperture I would have used in a certain situation.
But with a larger lens collection I can see it being an issue. ...Show more →
it might be worth it to them to sell that as an app at least. that would require sony to think a little about their app store...
Sep 09, 2014 at 11:23 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
I wanted to add that I think for these two lenses it might be a good thing that they don't allow you to focus wide open and then automatically stop down before shooting (what I generally think of as auto-aperture). I really like lenses with auto-aperture, but I want them to have very little focus shift. I'm not at all sure that these lenses have small enough focus shift for auto-aperture to be useful.
Said another way, my preference is for auto-aperture on a lens with very little focus shift (likely with floating elements) and a native mount, but only on such a lens. If a lens has much focus shift at all, however, I would rather have the mechanical aperture that is one these Loxia lenses. If stopping down is going to move the focus point, then shooting wide open to precisely place the focus point is pretty pointless. I would rather start at the working aperture and use magnification or play with focus point in the viewfinder to try to identify the focus plane I want. I am not at all sure these lenses will be free enough from focus shift for me to want auto-aperture.
And maybe if they make some better lenses later with floating elements and very low focus shift, then they will also build in the capacity for auto-aperture. Until then, I am not sure that the feature would be that useful anyways.
It's a strange thing about focus shift...the old Canon LTM 35/2 which I have been testing shows no focus shift whatsoever yet it has no floating elements nor modern glass types. So, I think it has much more to do with the actual, basic design.
Sep 11, 2014 at 09:09 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
Tariq Gibran wrote:
It's a strange thing about focus shift...the old Canon LTM 35/2 which I have been testing shows no focus shift whatsoever yet it has no floating elements nor modern glass types. So, I think it has much more to do with the actual, basic design.
I really think it has to do with spherical aberrations. If the lens has very low SA wide open, then it will have very little focus shift. If it has SA, however, then it will show focus shift unless you correct for it with a floating element (a floating element also improves resolution at close focus distance even if there is no SA, so that is why it is nice on lenses like the new Otus line). At least that is my understanding that may be too simplistic. It is that reasoning, however, that makes me think auto-aperture on these lenses wouldn't be that helpful. They have a noticeable amount of SA wide open and no floating elements, so I think they will show a non-trivial focus shift. The focus shift may well stay within the depth of field when you stop down, but if that is all you want then you might as well focus stopped down. If you want precise positioning of the focus plane, then you need very low focus shift.
Steve Spencer wrote:
I really think it has to do with spherical aberrations. If the lens has very low SA wide open, then it will have very little focus shift. If it has SA, however, then it will show focus shift unless you correct for it with a floating element (a floating element also improves resolution at close focus distance even if there is no SA, so that is why it is nice on lenses like the new Otus line). At least that is my understanding that may be too simplistic. It is that reasoning, however, that makes me think auto-aperture on these lenses wouldn't be that helpful. They have a noticeable amount of SA wide open and no floating elements, so I think they will show a non-trivial focus shift. The focus shift may well stay within the depth of field when you stop down, but if that is all you want then you might as well focus stopped down. If you want precise positioning of the focus plane, then you need very low focus shift....Show more →
The Canon does have SA wide open yet it still shows no focus shift (tested at infinity). Anyway, it's curious as I agree that SA is the commonly pointed to culprit for focus shift. At F2 there is very little dof so that's not what's going on in this particular case. It will be interesting to see just how much focus shift these newer Loxia lenses have. I take it their ZM cousins show quite a bit?
Frankly, what I'm most curious to see with regard to new Zeiss glass is the ZM 35/1.4 Distagon. That may very well prove to be the most exciting thing they release. As a Distagon, it may even prove to perform nicely on the A7's. Heck, they probably even designed it to do so (since they likely plan on releasing a Loxia version down the road anyway).
The ZM 35 has SA wide open the ZM 50 has none (or almost none). The ZM 35 has minimal focus shift, the ZM 50 has practically none. Both lenses are claimed by Zeiss to have been designed to minimize the focus shift to insignificant levels in practical use (probably for film shooting, digital is more demanding).
With the mechanical apertures of these lenses focus shift isn't likely to be an issue anyway. Personally, I would just set the aperture to the final aperture and then focus, obviously there wouldn't be focus shift in this situation. Even if you focussed at max aperture and then physically changed the aperture ring to the desired aperture, then I would think that movement as you changed apertures would be a bigger issue than focus shift unless you were on a tripod, and if you are on a tripod you can certainly use magnification to tune the focussing at shooting aperture, so I can't see how focus shift would ever come into play at all with the mechanical aperture of these lenses.
If they had auto-aperture, however, it very well might, but they don't.
Sep 11, 2014 at 02:47 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
Tariq Gibran wrote:
The Canon does have SA wide open yet it still shows no focus shift (tested at infinity). Anyway, it's curious as I agree that SA is the commonly pointed to culprit for focus shift. At F2 there is very little dof so that's not what's going on in this particular case. It will be interesting to see just how much focus shift these newer Loxia lenses have. I take it their ZM cousins show quite a bit?
Frankly, what I'm most curious to see with regard to new Zeiss glass is the ZM 35/1.4 Distagon. That may very well prove to be the most exciting thing they release. As a Distagon, it may even prove to perform nicely on the A7's. Heck, they probably even designed it to do so (since they likely plan on releasing a Loxia version down the road anyway).
As I understand it focus shift is always smallest at infinity and greatest at MFD. So no focus shift at infinity might not mean no focus shift at MFD. Maybe somebody can help us understand this a bit better.
I agree that the ZM 35 f/1.4 would be very exciting. Has it been confirmed yet? Personally, that is the lens I would be interested in among these releases by Zeiss. A Loxia version would be even more interesting to me.
Steve Spencer wrote:
As I understand it focus shift is always smallest at infinity and greatest at MFD. So no focus shift at infinity might not mean no focus shift at MFD. Maybe somebody can help us understand this a bit better.
I agree that the ZM 35 f/1.4 would be very exciting. Has it been confirmed yet? Personally, that is the lens I would be interested in among these releases by Zeiss. A Loxia version would be even more interesting to me.
Today I did some MFD backlit flare testing with the Canon and noticed no major focus shift either. Flares like crazy though!
In some other geeky lens research I was doing today, I saw it mentioned that lens coatings also play a role in focus shift. The specific example mentioned was Konica. Konica released two versions of their LTM Hexanon 35/2, one silver and the other a black UC-Hexanon. Both share the exact same optical design but the black UC-Hexanon has superior coatings on all lens surfaces and apparenly, some of the internal elements of the other one lack this. It was claimed that the earlier version shows focus shift whereas the later UC-Hexanon black version does not - and the coating was singled out as the reason. Of course, this was on another forum so who knows how reliable the info is.
Actually to be honest using the rear screen on the A7/r comes very close but again there is the problem of the focusing stopped down. I love shooting with the screen angled to be a WLF.