In this article, I will take another look at the Sigma Cine Art Classic prime set. I bought a full set of Sigma ART Classics back in December and finally they have arrived. You may have seen my last post about them and the first test that came along with it here. At the time only 2 lenses were available, the 35mm and 50mm. I have now had a chance to look at all the lenses available in the set. The set includes 14mm T3.2 (F1.8) , 20mm T2.5 (F1.4), 24mm T2.5 (T1.4), 28mm T2.5 (T1.4), 35mm T2.5 (F1.4), 40mm T2.5 (F1.4), 50mm T2.5 (F1.4), 85mm T2.5 (F1.4), 105mm T2.5 (F1.4) & 135mm T3.2 (F1.8).
Whats different than what I initially saw?
With no solid answers from Sigma, they seem to have adjusted and finalized the front and back coatings a bit. The images are slightly less reactive to stray light than the two lenses I tested. This is actually a good thing. They have a more pleasing, clearer and defined flare now. This doesn’t mean that they have lost any of the wild magic the original two lenses I tested have, they simply are a bit easier to control. I also finally got to see the new housings and markings. The physical build is nearly identical to the standard Cine Primes. They still have the same milled aluminum housings and stainless steel PL mount, but to differentiate the different product lines, there is now a stainless steel band on the back. The addition of Cooke /i technology is a welcome addition. The Sigma Art Classics will transmit data to any camera that takes /i metadata protocol.
There is also a new “Classic” insignia that is hand painted on the lens barrel with a technique called Aizu-Nuri. It’s the centuries old traditional Japanese lacquer technique thats native to Aizu Japan, the home of Sigma. Sigma made a limited run of the Classics, only 30 sets worldwide. As opposed to just stamping a label on, Sigma decided to use local artisans to apply the logo with a special gold lacquer. It’s a small detail, but goes to show the “family” business nature of Sigma. They included some of their region’s cultural heritage in the creation of their lenses. I like that.
The last difference between the standard Cine Primes, is the iris markings. The Tstop markings are different to reflect the new light transmission ratings, or T-stop of the lens. The lack of all internal coatings, reduces the glass’ ability to allow light to pass through. There is about 4% loss of the light per surface between glass and air. That 4%, is then reflected back and scattered, causing flares. It does, however reduce the amount of light thats transmitted to the sensor. The optics are still F1.4(F1.8 for the 14mm and 135mm), but their Tstops, the transmissive rating is lower as a result. What is interesting is that a standard Sigma Cine @T1.4 will have identical Depth of field as a Sigma Classic at T2.5 as the apertures and optics are the same.
I made a few videos to demonstrate their look, and effects. The first video is a simple lens test directly comparing the Sigma Cine Primes and the Sigma Art Classics. I shot on Lumix S1H Full frame 4K @ AVC-All-i 400mbps in 10bit 422 recording. The camera was set at ISO320 to remove any noise from the signal, and reproduce the lenses image quality with more fidelity.
There was a base ambiance from sunlight of T2.8 1/2 @ ISO320, and we keyed with a LitePanels Gemini. There was a bounce card on the ground returning some of the skylight back to our model Jennie’s face. The back light that was used to directly flare the lens was a LitePanels Sola 6 in daylight 5600K color temprature. The hand held light for a central flare was a Litra Pro LED. The RGBWW light used for the color flare test video, was a Litra Studio LED. The key was at T4.0, and the back light was 1/2 stop over key.
The first video is a more direct comparison designed to show you exactly what the differences are. I used the stock Panasonic Vlog to 709 LUT, and did not adjust the footage for exposure. The lighting was the same and the lenses were both set to T4.0. This is to show how the contrast, flares, and over all luminance changes between the coated vs uncoated lenses. Pay attention to the black levels, and over all color rendition. I found the Classics to be obviously lower contrast, but more interestingly, much warmer. The consistency of color was relatively stable between focal lengths on the Classics, and of course rock solid between the Sigmas Cines. It seemed from the results that the edge to edge sharpness is pretty good on the Classics. They also match in terms of sharpness to their coated brethren. The general run of the test (however informal) is that the lens begins flared, by the back light as it racks into focus from the slate. The back light is turned off, to show off the natural contrast. Then Jennie, turns on a hand held light to show the effects of a center of frame flare, moves it around, then blocks it from the lens to more dramatically show what it is doing to the image. Then the focus racks to the background, then fully to minimum focus to show bokeh quality and any artifacts from the lack of coatings in the bokeh. Remember to look for the visually shallower depth of field. Despite the same Tstop between both lenses for exposure, the Classics are effectively a stop and a half more “open” optically. So the depth of field is shallower.
In this Second video, it is essentially the same video as above, just that the shots are graded. The Sigma Cine shots have a small amount of contrast applied. The Classics shots have quite a bit more, to help the shadow areas reach black, and give you a sense of what the lenses may look like with regards to a finished grade, as compared to shooting on the standard Cines. It’s more or less to give you a sense despite the lower initial contrast what a final product may look like. The same Panasonic Vlog to 709 Lut is applied, with a bit more contrast applied in a separate node in Resolve using the Lift,Gamma,Gain wheels.
This final video shows off one of the more interesting effects of the lack of coatings. The flares. The Classics have an interesting byproduct. Unlike vintage lenses that actually have coatings on each element, albeit simpler coatings, the Classics have no coatings at all aside from the very front and very back elements. Coatings add a distinct color to their flares. Different coating compositions can cause different colors. The Classics, as there is no coating, the flare is “White”, that is to say it takes on the colors of the source creating it. This gives you some interesting creative options. If you control the lighting in the frame to produce no flares, you can use a colored RGB led point source, or a hard light with gel to create a flare that has any color you like. This is not to say that other lens won’t produce flare based on the color of a source, but that color will be mixed in with its native color. This gives you great control. If you are shooting a commercial for example, and the company colors are a specific shade of pink or purple or red or blue… you can dial that number into a RGB light or make a gel pack to create that color exactly, and create lens flares that matches the source’s color. See below for some demonstrations. We did not have a fresnel light that was RGB, or any gel to color a point source so we used for demonstrations sake, a small RGB panel to induce flares. It also includes some shots in daylight, with sun flares and heavy back lighting to give you a sense of how they look when provoked.
These lenses are not necessarily a set you would shoot everything on. Nor are they meant to be. They are, like traditional “vintage” lenses used for their specific look and characteristics. I use them on music videos, dance films and dreamy ethereal commercial projects. Some times its even nice to use them just for specific shots, sequences or portions of a project. They also work wonderfully for taking still photos too. I use a PL adapter for my S1H, and take portraits and experimental images. The classics remind me of my 1908 Wollensak Cine-Velostigmat 35mm F4.0, in that you get a pleasant surprise whenever you point it at a new subject. I personally love how incredibly reactive the wide angle lenses are in the classic set. I could see them creating some amazing effects in a nightclub setting for music videos. They could also be very interesting for shooting automotive, as the headlights will create explosions of light and color. Flickering sources, or something like the sun shafts between the slats in a pier or train trestle, while moving the camera would be like fireworks. There is a lot of creative potential. With the strong flares on the sensor side of the camera, and immense control we get with our images these days with RAW capture and post color, there is a lot that can be done to bring the image somewhere new.
All in all, they offer a specific, very charismatic look. Warm, hazy, flares like a champion. There are no other lenses available that I know of that are this reactive to light. While they are named Classic, they truly are something new.
Amazing article and videos. Don’t you think the footage is too soft (classic), or this can be altered in post?
I agree with you regarding it sensitivity to light, but it might be a burden when you wish to subdue the flares.