Angry Photographer proves the 105/1.4E isn't "flat"

Started Oct 4, 2016 | Discussions thread
nottabot New Member • Posts: 7
Re: A different view...
3

Hello, I don't like to post on forums too much but I was asked to write about lenses a bit; someone I know is interested in buying the Nikon 105mm f/1.4.

There are a few people (I'm not talking about any specific forum) that tend to dismiss what others have said because they're not a professional photographer or their work isn't very good. I tend to follow a "formula 1 racing" style approach in that if I wanted to learn about engines, I'd be more inclined to speak to the techie guy that repairs engines rather than the guy that drives the car. If I wanted to know about handling, that'd be a different story altogether. I'm not an expert photographer but I do know a bit about science, optics, lenses and whatnot. Moreover, if an argument is valid, then it is valid. I hope the fact I'm a nobody doesn't make you dismiss some of my arguments. You can try all of this yourself, but some of it you might have to research if you don't believe my claims e.g. radioactive materials were used in old lenses.

I was linked to an off putting video made by Theoria Apophasis. I haven't tried the lens in question; I cannot tell you if it has good micro-contrast. I can only say that this video should not be trusted. Ultimately his primary argument that the lens is bad, might be accurate; I have no way of knowing.

A high element count does not necessarily mean a low micro-contrast or low transmission lens.

Think of glass like a piece of wood and a bullet (photon) has to go through it. You could have ten extremely thin planks of wood and a bullet would have no trouble going through all of them. If you had one plank of wood that's twenty times thicker than all of them put together, the bullet might struggle. In this instance, it is the volume of wood rather than the quantity of wood that defines whether or not the bullet can penetrate.

With glass, there's also the complication of the chemicals used to make the glass and to coat the glass. You could have an equal amount of elements and an equal volume of glass but one lens would perform substantially better than the other if its inherent proprieties were better.

If you research old, obsolete lenses, you'll find various companies used Lanthanum and Thorium amongst other chemicals (Lanthanum is still used but it's 1/10,000 as radioactive as Thorium); this helps with refractive index. A Geiger counter will clarify the presence of a radioactive material. Companies don't just use Lanthanum or Lead, and they don't simply stick with one type of coating and leave things be; technology evolves. Lenses aren't just pieces of glass. Lenses are obviously different to wood and there are negatives (there are also positives) to multiple elements but my point here is that you cannot blindly assume a high element count lens will be a bad lens. If you haven't been told the volume of the glass, just what calculations would you be doing?

I've seen two photographs to demonstrate "poor micro-contrast" and in my opinion, they're an excellent photograph to debate. It is something the average person might look at and think "wow, look at the difference."

https://www.flickr.com/photos/134746128@N05/29862664812/in/dateposted/

If we copy the left photograph and place it over the right, we'll see they're completely different sizes. If we crop them to be the same size, and we crop off the bottom to remove the text; we're left with something like this -- http://imgur.com/a/YwWFW.

In the YouTube video concerning these photographs, Theoria Apophasis states the exposure was exactly the same. I'm not sure how the exposure was measured, but here's a few key points.

  1. After you've made the photographs the same crop factor, e.g. a square, and you run a separate histogram on each photograph, you'll discover the exposure is not the same at all
  2. A lens can have completely different transmission (how much light it lets through) so even if the camera says it's the same exposure, it might not be
  3. I suspect the newer lens has greater transmission at the same f-stop, despite the fact it's got more elements but I could be wrong; this is an assumption based on these photographs

https://i.imgur.com/lzap5UJ.jpg

As we can see, the histograms are vastly different but when we add 0.33+ exposure to the left photograph, the values become similar. From there, we can plot various "eye dropper" tools to measure specific points around the photograph to check whether the values are the same. I've discovered that if I add 0.33+ exposure to the left photograph, it doesn't just fix the brighter tones but it fixes the darker tones as well. It's a bit haphazard. At first I thought this was simply down to the lenses being slightly different focal lengths due to focus breathing, but it appears the photographs were actually taken at slightly different angles.

If you copy and paste a black and white photograph over itself, and set the layer mode to "difference", it should be completely black because there's no difference. If we do that with the photographs shown on the flickr page; the results are astronomically different. This cannot be used as an accurate measure for objective testing. If you are to measure micro-contrast objectively, you HAVE to use a tripod and you HAVE to use studio lighting while indoors. Clouds can move, the Earth rotates, and the results vary dramatically. If you own a lens for long enough, I'm sure you'll get a feel for the kind of micro-contrast it has, but in terms of an objective review is concerned, the result here is no good. It can't be used to measure a lens accurately. Theoria Apophasis states the exposure is correct but clearly it is not; the black levels are proportionately incorrect too (they're darker on the left photograph). You can try this yourself and you'll get the same results. I'm working from JPGs here but most of the claims in the video and the results shown are so wildly inaccurate that I don't think it matters.

One mistake I think people make is they look at objects, it doesn't matter what they are, and then they begin to make assumptions. For example, if you had never heard of a vehicle before and you saw a Ferrari drive by at 5MPH, but you only saw Coaches do 30mph, you might make the assumption that Ferraris are not very fast. People look at big lenses and they assume they have to be big (to an extent this is true, but I won't get into that subject here). People look at high element count lenses and assume they have to be bad. It's not necessarily so.

Theoria Apophasis also states that to "insult a fool is the praise of wisdom." Personally I think this is not logical. Digging a hole under someone's toes does not elevate yourself. For that reason, I kindly ask that if he does post here insulting me, admin does something about it.

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tko
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