Model Shoot / Studio Lighting

Infra-red photography isn't very common in the studio (from what I can tell), so when I got a chance to photograph a model in a proper studio environment I just had to give the full spectrum Sony A7 a try with an IR filter...

Zeiss Sonnar 55/1.8 + Kolari Vision Red Filter

Model: Estrany
Studio: SunShotStudio, London

    Canon FD 85mm f/1.2 L (lens 1)
I started the shoot by using the manual focus Canon FD 85mm f/1.2 lens (not for above photo), because I'd just bought it that week. It seemed like a good choice at the time but as it turns out there were several issues using it in these conditions. While triggering the studio lights mirrorless cameras need to have their WYSIWYG (What You See Is What You Get) exposure settings deactivated in the menu. For the Sony A7 this means turning the 'Setting Effect' [Off]. If you don't do that the viewfinder would be black while using the low level modelling lights if the camera is in full manual mode (which it should be).

Using an old manual lens adapted to mirrorless caused the biggest problems. Since the aperture values are set on the lens itself shooting at f/11 made the EVF grainy and sluggish. Both focus zooming and peaking features suffered from being relatively sharp due to the small aperture and high grain. All this made accurate focusing time consuming and generally difficult.

    Hot Spot
Although this lens doesn't suffer from hot spot badly in general conditions it was quite problematic here due to high contrast from the studio lights and realitively small apertures. If I could have shot wider than f/5.6 this probably would not have been a problem, but because that was impossible without heavy ND filters (which would have introduced more problems) I could not avoid it.

Canon FD 85/1.2 L + Hoya R25A Red Filter

    Available Light
Before I attached the wireless triggers I did take some photos with the Canon 85mm lens wide open using just the modelling lights. I got away base ISO here, but only just. Although I like the shallow depth of field I don't think it's particularly effective here, without a nice background to blur out. Since the subject is already isolated it seems a little pointless. That said, what blur you get does add a little to the ethereal feel. I quite quickly moved onto another lens...

    Zeiss 55mm f/1.8 FE (lens 2)
For the rest of the shoot I switched to a lens that not only performs better in infra-red, but is much sharper too. Since this lens is made for the Sony A7 everything got a lot easier from here on in. Native E / FE lenses work just like SLR lenses in these conditions. In that the aperture diaphragm goes wide open while focusing and then stops down to shoot. This lens' image quality is extremely impressive, but the same cannot be said about the cameras ability to autofocus in these conditions.

Zeiss Sonnar 55/1.8 + Kolari Vision Red Filter

Click on the below image to see a 100% crop from the above image.

    Bad Autofocus
Although the Zeiss lens was very accurate when the focus did lock, the speed and reliability of that AF under the modelling lights was considerably poor. This didn't seem to be a problem with the infrared spectrum, more the camera system itself because I also tried the non-converted Sony A7 mkII with the same lens and the same thing happened. At times it would just hunt back and forth, even though there was seemingly plenty of light and contrast detail. It would also sometimes give up while completely out of focus, even though the shutter was still half pressed. Under the same lighting conditions a mid range DSLR that my friend was using focused far more quickly and 100% of the time.

Zeiss Sonnar 55/1.8 + Kolari Vision Red Filter

    Colour / WB
I shot using a simple red filter (on the full spectrum Sony A7) 100% of the time. This equates to 590-600nm IR conversion. Although this can provide too much colour for some conversions it seems about the right balance with the Sony sensors as they seem to be extremely sensitive to IR light. My thinking behind only using this filter was that I wanted the ability to process colour IR from any of the images in post and if not then I would just desaturate them.

• Left: Canon 6D / EF 50mm f/1.4 - @ f/9, 1/160th, ISO 100 (400-70nm)
• Right: Sony A7 / FE 55mm f/1.8 - @ f/11, 1/160th, ISO 100 (600-1200nm)

    Exposure & Brightness
Colour infra-red may not have as much contrast as pure IR, but it lets in a lot of light. As well as providing extra processing options it also gives brighter exposures than a normal colour sensor. With the studio lights at minimum brightness the colour shots were coming out with nice punchy shadows, but the IR shots were literally glowing by comparison and that with a smaller aperture. The shutter speed was already at maximum for the studio lights and a smaller aperture would have blurred the image from diffraction, so I had nowhere to go here without using ND filters. Fortunately I rather like the tones of this exposure and fortunately the highlights weren't just about retrievable in RAW (no quite blown).

Zeiss Sonnar 55/1.8 + Kolari Vision Red Filter

Zeiss Sonnar 55/1.8 + Kolari Vision Red Filter

    Tones
Pushing the exposure down a few stops in a RAW editor shows some more neural values but it still has a different look/quality to it compared to a desaturated visible colour image. What stands out the most is how veins can show up. I find this fascinating and pretty, but I imagine that it'll be a love/hate thing for most.

Zeiss Sonnar 55/1.8 + Kolari Vision Red Filter

    False Colour
Flipping the red and blue channels works great on tress and water in landscapes, but it can make people look weird or even horrific. I quite like these results here though, but perhaps that's because there isn't much separation of colours going on, it's a bit like a split toned image. Some of the pleasing aesthetics also come from the high contrast lighting. If you try this in an overcast day outside then the results are very hard to get right.

Zeiss Sonnar 55/1.8 + Kolari Vision Red Filter

Here is one of the shots that I've done some enhancements to in Photoshop (you can see the original above). Apart from the obvious teeth extensions I've added longer nails and brightened the eyes. I did ask for a vampy pose here and she did a great job, but in hindsight I chould have been better with direction. If I get a chance to do this again I'm going to ask for more teeth and maybe a profile version could be cool too. I'd like to do another shoot with Estrany outside and not shoot exclusively IR, but that probably won't be a vamp friendly scene.

Well I thoroughly enjoyed this shoot and I'm still processing many of the shots from it because there is so much you can do to them. I really can't wait to do another model shoot, but my next one will be outisde with while I return to using the 85mm lens.

If you have any questions about this shoot, or suggestions for the next one please feel free to post a comment below or email me here. 

Lens Review - Sony FE 28mm f/2.0

For over a year I have been using the full spectrum A7 with only manual lenses (Nikon and various other legacy glass). I recently bought and tested the Carl Zeiss Sonnar FE 55mm f/1.8 and found it to be the best infra-red performer I've ever seen! If you're thinking "of course it's good, it's an expensive Zeiss lens" think again, as I've heard reports of bad hot spot performance in almost every other Zeiss lens for the Sony FE system.

This 28mm is the cheapest prime lens for the FE system by quite a bit. It has a surprisingly fast f/2 aperture for its price too and although it's not that small (what fast FE lens is?) it is quite light. In the handfull of tests that I've seen for this lens it comes out pretty well for visible colour, but let's see what kind of skillz it has with infra-red...

      Stats
● Mount: Sony FE
● Adapts to DSLR: No
● Adapts to (other) ILC: No
● Focal Length (FF): 28mm 
● Field of view (FF): 75°
● Lens Elements: 9
● Lens Groups: 8
● Aspherical Elements: 3 (1 Advanced + 2 ED)
● Aperture range (f stop): 2.0 - 22
● F-stop increments: 1/3
● Aperture Blades: 9 (curved)
● Aperture Ring: No
● Autofocus: Yes (silent)
● Manual Focus Ring: By Wire
● Min. Focus Distance (cm): 29
● Max Reproduction Ratio: 1:7.7
● Internal Focus: Yes
● DoF Scale: No
● IR offset markings: No
● Body Material: Metal
● Filter Thread Material: Plastic
● Filter thread: 49mm
● Static Filter Rotation: Yes
● Dimensions (mm): 64 x 60
● Weight (g): 200
● Dust / Moisture Sealed: Yes
● Mount Seal: No
● Manufacture Country: China
● Manufacturing Span: 2014 >
● Price New: £240 - 400
● Price Second Hand: £220-300
● Accessories (Included): Hood

     Quick IR Performance Scores

● Pure IR HotSpot (Lack of): 5/10

● Colour IR HotSpot (Lack of): 5/10

● IR Sharpness (Middle): 6/10

● IR Sharpness (Edges @ f/8): 4/10

● IR Sharpness (Edges @ f/2): 2/10

IR Quality / Hot Spot

Here's a new set of images, a test for IR hot spot that I'm trying out (see more about it here). Basically what you're looking for here is a clean dark sky, with no bright spots.

This lens does vignette fairly heavily wide open and that can look like a large hotspot, but most of this is not. You'll find the hot spot more obvious here closer to the bottom of the set. This 850nm IR filter shows a patternef spot starting to get anmoying at f/8 here, but if a clean sky is important to you then even f/4 is still an issue. To some extent the hot spot is always there, it just gets larger, more blurred and subtle as the aperture opens up. Since this is the worst case scenario here f/8 is almost always fine under normal shooting conditions and mostly so is f/11. Thus I would say this lens is generally acceptable in relation to the hot spot issue. If you're someone who shoots pure infra-red at f/16 - f/22 often then I'd recommend you think carefully before buying this lens.

Here is a video to show the hot spot performance at f/22. This helps show how related to the bright areas of the scene they are. Unlike a standard circular spot these are not very easy to remove and compensate for.

This next set was shot using a Hoya R25A filter. On a full spectrum camera this is very similar to a 590nm conversion.

Although the sky wasn't quite so clear when I took this set with the R25A filter you can still see how much cleaner the colour infra-red is compared to the pure 850nm B&W samples. This could be partially because of less IR light coming through the filter, but also because of the reduced contrast in the scene. All the noticeable hotspot here is contained in the blue channel, not that it's much comfort if you're trying to process a colour IR image.

Check out these next couple of samples to see how some particularly high contrast scenes can be problematic, even at wider apertures. These are both shot at f/8, which is much more distressing. The bright spot here shows up very clearly on the tree trunk. I'm showing two samples here to show how the spot moves and confirm that it's not a fluke light on the tree itself.

Lens Flare

Here are some samples at different wavelengths to show how it copes with unavoidable lens flare in each. These are all shot at f/8. As you can see the more infra-red light that comes through the filter the more obvious the flare becomes. It's actually very good in colour and even when external filters are used like this. In IR however it looks downright horrible. I wouldn't advise shooting into the sun when taking infra-red photography on this lens.

 Kolari Vision Hot Mirror (Colour)

 Hoya R25A (Red / 590nm)

B+W 093 (850nm IR)

Sharpness

When I did a test between colour, UV and IR filters recently I got a lot of good comparison samples for this lens at different wavelengths. The difference in sharpness between the colour shots and all infra-red ones was quite noticeable. It was obvious overall, but in the corners it was especially apparent. All the shots were taken on a tripod and with accurate autofocus so I knew it was a fair test. I was unhappy with this lenses IR shots before this test and after looking closely at these samples I could now see exactly why. Click the image below to see the comparisons for yourself. It even shows up on these compressed samples at less than 2 mega-pixels, thus they certainly don't stand up scrutiny at 24mp (nearly fourteen times the size).

Competition

Like most Sony lenses there isn't much in the way of competition for autofocus lenses (yet), but there is more here than with the 50mm FOV. There is now a 25mm f/2 in the form of the new Zeiss Batis, which is a high performance lens and has the added size, weight and cost associated with the brand. You could also get a Canon EF 28mm f/1.8 with an AF adapter. It might be a little faster than the Sony lens, but focusing will be sluggish on the first four A7 bodies. A potentially larger issue is the size and price by comparison (not including the cost of the adapter). I actually paid £100 less for the Sony 28mm lens (with a cashback deal) than the Canon usually costs.

If you're willing to forgo autofocus and buy second hand primes there are many options, but it will be hard to save money while keeping decent image quality and the relatively fast f/2 aperture. Although some old 28mm f/2 lenses can be picked up from companies like Vivitar or Sigma for a little less money, they tend to be rather lacking in corner quality. Models from Pentax, Canon and Nikon are interesting for their image quality, but they cost as much or more than the autofocus Sony. Although the adapters for them can be cheap they make the lenses quite a bit bigger and heavier too. Mostly front heavy & oddly balanced compared to the Sony 28mm.

The Leica M mount Voigtlander Ultron (with adapter) will be a better match for the size and performance of the Sony lens (albeit it a bit heavier), however it will cost more, have an odd filter size and still be without autofocus. On the flip side it does look cool on the A7 bodies (or retro, or hipster, depending on your opinion).

Conclusions 

I wish there were more lenses like this for the Sony A7 series FE mount - Primes with faster apertures, at a more reasonable price (and quality). If there were I'm sure that the Sony A7 series would be even more popular than it is already. Perhaps Sony are hoping that 3rd party lens makers will fill these gaps later, but that was a risky strategy when they started out. Now that they've done so well there's a much bigger chance of that happening. Thus I feel much better recommending the system to people on a modest budget these days, but it certainly wasn't like that, even a year ago. As it stand right now, this Sony 28mm f/2 feels like the odd one out in an exclusive, high-end catalog. The FE lens collection is growing fast though, so this could change with the next announcement. I'm certainly crossing my fingers for more lenses like this soon.

In visible colour this lenses is a brilliant addition to the FE system and a game-changer for value primes, but... for infra-red I'm not at all convinced. Its IR quality just doesn't match that of its colour performance. It's like a totally different lens in infra-red and that's a real shame because this could have been a very nice walk-around landscape lens indeed. The hotspot that it produces isn't even the main problem. It's not the most extreme hot spot I've seen, nor does it show up often during normal shooting, it can just be problematic at times. The main issue here is sharpness (and to a lesser extent contrast). Infra-red photography can be passable, but it just never seems to shine. Clarity is generally low. Corners start to get better when stopping down heavily, but not long before diffraction becomes a problem. Now I'm making it sound plain horrible here and that's quite not fair.

Perhaps I've been spoiled by the insane performance of the Zeiss FE 55mm, but I do feel that if you're someone who zooms in on your photos to revel in their beauty in any way you won't be happy with this lens for infra-red.

General Pros and Cons

    Pros (rated out of 10 for how awesome they are)
(9) - Accurate and silent auto focus
(7) - Good construction (metal... mostly) and great balance with the camera
(6) - A great value prime lens for Sony FE at last (although not really for IR)
(4) - Included lens hood is nice

    Cons (rated out of 10 for how annoying they are)
(9) - Infra-red is noticeably less sharp and especially in the corners
(8) - Nasty looking lens flare in IR
(6) - Hot Spot can be problematic
(5) - Focus by wire speed is inconsistent, lack of feedback make it difficult to use
(5) - No Aperture ring
(3) - Plastic filter thread (forgivable at this price though)
(1) - Vignette could be better

Overall Score (Colour IR): 4/10

Overall Score (pure IR): 4/10
Below Average IR Performance

   IR Samples

Here are some b&w infra-red images, taken with the B+W 093 filter (on the full spectrum Sony A7). This filter has a 50% transmission at 850nm (the amount of visible light that passes through this filter is nominal).

 f/4

 f/11

  f/8

  f/11

 f/11

Here are some colour infra-red photos taken with the Hoya R25A (Red) filter (on the full spectrum Sony A7). This is equivalent to about a 590nm conversion. All images are processed using the 'false colour' technique:

 f/8

f/11

f/22

This last example shows the real-world colours (before WB / channel manipulation), exposure and tones of the hot mirror, 850nm and Hoya R25A filters together. The overlapping of the first two show a near black image. This illustrates what happens when an IR filter in front of a normal (non-converted) camera. The latter two show that a low wavelength conversion can be switched to a higher one by using external filters.

f/5.6

Bonus - Multi-Spectrum Sample

This lens seemed to like UV a bit better than it did IR. It was more sensitive than the Zeiss 55mm f/1.8 even though it wasn't quite as fast. Here is a test shot of it using the Baader-U UV filter showing some sunscreen. The shoulder stripe had just been applied here, but the sunscreen on the face was applied 3 hours before and been washed just before taking this image. Showing that it does stand up to water somewhat, like it is supposed to.