Steve Spencer wrote:
You are demonstrating that you do not understand what APO actually is. It is not focussing red, green, and blue on the focal plane. It is focussing three specific wavelengths (e.g.. 525 nanometers, 780 nanometers, and 1100 nanometers) on the focus plane. All the other wavelengths still do not focus exactly on the focus plane. So it is a very specific red (or maybe an orange), a very specific green (or maybe a yellow), and a very specific violet (or maybe a blue) on the focal plane (and sometimes it isn't even a red in the visible spectrum but an infrared and sometimes it isn't a blue in visible spectrum but an ultraviolet) all the other reds, oranges, yellows, greens, blues, and violets don't focus on the focus plane. And whether a color focusses on the focus plane does not tell us anything about how well it resolves at that wavelength.
It is not a coincidence either that most lenses that are APO are sharp. Removing APO is not easy and arguably harder than making a lens sharp. So if you are designing a lens that you are going to the work of making it APO, you are also likely willing to go to the work of making it sharp, but there is no necessary relationship. It is also true that luxury cars tend to have engines with more horsepower, but nothing about having a high horse power engine makes a lens a luxury car. Just if you are designing a car with a big engine you likely are going to also go to the work of making the ride smooth and making the interior nice. So, it isn't a coincidence that luxury cars have high horsepower engines, but having a high horsepower engine has nothing to do with making a car a luxury car....Show more →
"When light passes through any lens it is bent. The different wavelengths are bent to different degrees which means they will not all focus at the same point. This causes chromatic aberrations and an image that has colour fringes and less sharpness around points of highest light contrast."
"Compared with a standard lens of identical speed and focal length, an Apochromatic (APO) lens displays considerably better image quality."
Maybe after you contact Voigtlander to point out their mistakes on their site you should contact Zeiss
We really are lucky here at FM to have experts like your self to combat all this mis-information that these fly by night companies put out on the web
Jim also tests the 65/2 against the Otus 55 in an aperture range and sees very little difference in the results, and notes a little fringing in the 65/2.
philip_pj wrote:
Terminology is always subject to interpretation, people are trying to communicate complex material in few words or sentences.
'you are also likely willing to go to the work of making it sharp, but there is no necessary relationship.'
Very true, as Jim Kasson found when testing the LoCA (a key test of APO) and sharpness characteristics of the 65/2 against the very APO (low LoCA) Coast Optics 60/4. It handily waxed this fine lens, and drawing on Fred's review and user experiences, the 50/2 is in the same ballpark for performance (lpmm).
So it is the combination of very high focal plane performance with APO character that makes this 50/2 so enticing, even before considering its aesthetic value and DOF effects.
The Coastal Optics had a different goal (UV - VIS - IR performance) and thus they spread the 3 corrected APO wavelengths over a bigger swath of spectrum. Check here for the transmission and APO waveband parameters:
That is an appropriate question and the answers are surprising.
I have already posted samples with an 850nm IR filter (850nm and upwards). The performance is spectacular in Infrared.
I will comment on the UV part at another time, separately and away from this thread.
However..
Given that a stock Sony sensor can see only ~410nm to 650nm, let us keep the focus to red-green and blue of the visible light spectrum that this lens is intended for.
Let us keep the focus
vdo1 wrote:
The Coastal Optics had a different goal (UV - VIS - IR performance) and thus they spread the 3 corrected APO wavelengths over a bigger swath of spectrum. Check here for the transmission and APO waveband parameters:
Again, Maybe you should let Voigtlander know. Since they are the ones that make the lens I think I will believe them over some guy on the internet named Steve.
"Voigtländer APO-LANTHAR 50mm F2.0 is a high performance manual focus standard lens optimized for the imaging sensors of Sony mirrorless cameras.
Inheriting the apochromatic optical design, the lens is highly corrected to eliminate optical aberrations including longitudinal chromatic aberration."
You really are unbelievable Entertaining though
Very interesting partial quote. You missed the next sentence which actually totally refutes what you are saying. Voigtlander says after what you quoted, "In addition, it is optimized for the ultimate performance of the resolution and contrast reproducibility. "
So what Voigtlander is saying is that the lens is designed to highly correct CA and *in addition* it is designed for his resolution and contrast. They are calling it an APO design because it is designed to have APO performance, but that is separate from the design to be high in resolution and sharpness. It looks like it is you that has misunderstood what Cosina has written about this lens. It is not an APO design that creates sharpness as you contend. It is a lens designed to have APO performance that is additionally designed to be sharp. But you can't even be bothered to read what Cosina has written instead you selectively quote misrepresenting what is on the site and then sarcastically suggest that what I am saying is in conflict with what Cosina has written when it is your point of view that is clearly refuted by what is on the Cosina web page.
Wow, did everyone wake up with sand in there v-gg this morning.....
Cosina website quote, first pagarghraph top of page for APO 50.
"Apochromat design is adopted to minimize the axial chromatic aberration of RGB, which constitutes the three primary colors of light, to zero as much as possible".
Middle of page
"Apochromat design In
order to support the current digital sensor with a high pixel count , axial chromatic aberration and chromatic aberration of magnification are thoroughly suppressed".
Bottom of page
"APO-LANTHAR is a title given to particularly high-performance products among Voigtlander lenses. APO-LANTHAR,"
nhsonyshooter wrote:
"When light passes through any lens it is bent. The different wavelengths are bent to different degrees which means they will not all focus at the same point. This causes chromatic aberrations and an image that has colour fringes and less sharpness around points of highest light contrast."
"Compared with a standard lens of identical speed and focal length, an Apochromatic (APO) lens displays considerably better image quality."
Maybe after you contact Voigtlander to point out their mistakes on their site you should contact Zeiss
We really are lucky here at FM to have experts like your self to combat all this mis-information that these fly by night companies put out on the web...Show more →
Again no need for the snarky sarcasm. Just nasty on your part. There is nothing in these quotes from Zeiss that I disagree with. The first quote is consistent with what I wrote earlier CA reduces sharpness, but you of course have to remember that even a lens poorly corrected for CA will not show CA in all instances. As in the example I described earlier the Zeiss ZE/ZF/Milvus 100 f/2 Macro can in some instance show a fair bit of CA and in these instances the CA does reduce the sharpness of this lens, but it would be completely wrong to describe this lens as not being sharp. In many situations when this lens control CA fairly well it is an extremely sharp lens even though it isn't APO and in several side by side tests in these situations it is sharper than the much better corrected for CA Voigtlander 125 f/2.5 APO Macro. In situations that are more challenging for CA, however, the Voigtlander is sharper in these side by side test explicitly because the CA that the Zeiss exhibits reduces its sharpness. If you read on the previous pages you will see I gave exactly this example and I made exactly the same argument that Zeiss is making here.
The second quote you seem to have made the mistake of equating image quality with sharpness. Of course an APO lens exhibits better image quality if you include as part of image quality--as the Zeiss article you are quoting clearly does--control of chromatic aberrations. But again you have made a selective quote and didn't note what else was written in this article. Near the end of the article Dr. Zugge revisits the question, "How do these corrections (i.e., APO corrections) affect image quality?" He answers that question by noting, "When you are out taking photographs, it is not the number of zeroes in the lens specification that matters, but the overall image quality. If APO correction is performed consistently and effectively so that the residual chromatic aberration can no longer be detected, unfortunately new problems will emerge. Long-crown and short-flint glass have very high refractive powers, so lenses using this glass will be very sensitive to tolerances. Any theoretically calculated imaging performance – however high it may be – is useless if the calculated quality cannot be reliably achieved due to excessively high sensitivity to tolerances." So this Zeiss article makes it abundantly clear both that APO correction is about reducing CA and using the types of glass that bring about these sort of corrections is not worry free and an automatic increase in overall image quality. The article itself makes it clear that in real world performance an APO lens does not automatically mean a sharper lens.
So, if you would read what I wrote you would see that I am not in disagreement with these statements from Zeiss and if you would read all of what Zeiss wrote you would realize that your position that a lens with APO correction is automatically going to be sharper is refuted by what Zeiss wrote in the article you quoted.
vdo1 wrote:
I’m here to admire (and possibly debate) the optical quality of the lens, even if I knew from the beginning that it’s not for me due to my personal preference for AF and close focus features.
You should try the CV 50/2 APO. If you admire optical quality, I have a feeling you may actually like it despite having to focus manually.
I think there are three specific ways the bokeh on the CV 50 f/2 APO is better than the bokeh on the FE 55 f/1.8. First and most obviously the bokeh on the FE 55 f/1.8 (and I had that lens for over 2 years) has quite a bit of bokeh fringing up through f/4. Second, the out of focus highlight on the FE 55 f/1.8 often have pretty visible onion rings, and third, especially at f/2.8 the CV 50 f/2 APO has those perfectly round out of focus highlights from the unique aperture of the lens. For a quite a few images these advantages of the 50 f/2 APO might not make a big difference, but I think for quite a few images they will as well....Show more →
I think the bokeh fringing is the most relevant of these, and it certainly is a major failing. I personally don't shoot the kinds of images where specular highlights are relevant to me, although the shape of the highlight is obviously directly related to how OOF backgrounds are rendered in an image. In the 4 years I've had the sony 1,8/55 I think this is the only occasion I've ever seen the onion rings, but I'm sure that for some people it's way more common because of the subject matter that they shoot.
tsdevine wrote:
Point me to an example of what you'd like to see, I'll dry to shoot something over the weekend. It's supposed to be warm, goopy, and soggy this weekend.....but I'll see what I can do.
And yes, I'll may sure EFCS is off at or above 1/800th or so.
-Tim
Thanks, I think that would be great. I suspect images with subject at close to mid range, say 2-5m or so, with a cluttered background would be useful and representative of normal use for a lot of people. A few random samples below (from various lenses but to illustrate the type of pic). Anything with a busy background, horizontal and verticals at a distance, would be good.
JohnJ wrote:
I think the bokeh fringing is the most relevant of these, and it certainly is a major failing. I personally don't shoot the kinds of images where specular highlights are relevant to me, although the shape of the highlight is obviously directly related to how OOF backgrounds are rendered in an image. In the 4 years I've had the sony 1,8/55 I think this is the only occasion I've ever seen the onion rings, but I'm sure that for some people it's way more common because of the subject matter that they shoot.
Thanks, I think that would be great. I suspect images with subject at close to mid range, say 2-5m or so, with a cluttered background would be useful and representative of normal use for a lot of people. A few random samples below (from various lenses but to illustrate the type of pic). Anything with a busy background, horizontal and verticals at a distance, would be good.
I've never been a fan of the bokeh of the 50/2, and the more pics I see I am not a fan of the color. It seems to have the Voigtlander yellow/beige tint that I see in their other lenses - like my 40/1.2. Color may be vibrant, but I wish they were Zeiss colors.
pdmphoto wrote:
I've never been a fan of the bokeh of the 50/2, and the more pics I see I am not a fan of the color. It seems to have the Voigtlander yellow/beige tint that I see in their other lenses - like my 40/1.2. Color may be vibrant, but I wish they were Zeiss colors.
Fred Miranda wrote:
You should try the CV 50/2 APO. If you admire optical quality, I have a feeling you may actually like it despite having to focus manually.
The best way to entice me is to start the “CV 50/2 APO-Lanthar images thread” and the other gentlemen here to fill it with highly compelling photos
Jan 11, 2020 at 08:45 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
vdo1 wrote:
The best way to entice me is to start the “CV 50/2 APO-Lanthar images thread” and the other gentlemen here to fill it with highly compelling photos
Go to the first page of this thread where Fred has a convenient list of the samples in this thread posted so far. There is already a very good beginning with a lot of compelling photos.
Jan 11, 2020 at 08:49 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
vdo1 wrote:
Because around that focal length I can have both AF and Close Focus with the Sigma Art 70mm? All the way to x1 mag? Plus a more palatable to me diaphragm shape? And, while not advertised as “APO”, the Sigma has very good CA control too?
Why does it have to be CV? Are we in some state of mind where we cannot reason beyond this particular brand?
I think you missed my point, which was if you would want the CV 50 f/2 APO and all that is holding you back is that it doesn't have close focus distance, then the CV 65 f/2 APO macro is there as an option if you don't mind the larger size and if you want greater magnification you are going to have to live with a bigger size. Nowhere did I say it has to be CV. There are a whole lot of options, but of course the CV 65 f/2 APO is the option that is closest to the CV 50 f/2 APO.
Jan 11, 2020 at 09:05 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
vdo1 wrote:
Interesting. So in your professional opinion, which of the following statements are best describing human behavior:
A) In a forum, people are most likely to click on, read and participate in threads where the subject line contains keywords of most interest to them
B) In a forum, people are most likely to click on, read and participate in threads where the subject line contains keywords of the least interest to them
C) In a forum, people are most likely to click, read and participate into random threads, ignoring the subject line
Additionally, please explain how comes that the bulk of this thread is about the APOidness of the lens, not the size, weight or some other parameter. Please pick a statement here too:
1) In a forum, people are most likely to debate the subjects of most interest to them
2) In a forum, people are most likely to debate the subjects of least interest to them
To the first set of options, I say D) none of the above. I have argued consistently here that people on this thread read and participated primarily because of Fred's excellent review (and the links to Phillip's excellent review) and that for the most part people here are quite sophisticated, knowledgeable, and care about the topic. If you want my professional opinion, I would add that theory and research on human behavior quite conclusively demonstrates that such people are not influenced by peripheral cues such as keywords in the title of a thread but rather by good arguments as they carefully and thoughtfully process information about a topic.
To the second set of options, I would again say 3) none of the above. I would argue that the discussion about the APOidness of this lens has emerged as a big point of discussion because people like yourself have raised this issue without understanding the nature of APO and that led to a discussion of what APO actually is and what that means for this lens. I certainly never said the nature of APO is not of interest to people on this thread. It is of interest to people on this thread, but that does not mean that people on this thread do not recognize that APOidness is only one feature amongst many and for a lot of us not the primary reason for interest in the lens. If you looks at Fred's review and how he handled the APOidness of this lens not surprisingly as the thread begins with his review, I think a lot of us would weigh APOidness exactly as Fred has done.
