Photo Walk - The Sky Garden

It's been way too long since I've made one of these 'photo walk' posts for IR. I have taken many infra-red photos while exploring lately, so I hope to do more posts like this soon. Here's something a little different from central London - 'The Sky Garden', at 20 Fenchurch Street.

Zeiss Sonnar 55/1.8 - 1/60th, f/5.6, iso 160 - B+W 093 filter

The building is otherwise known as the 'Walkie Talkie'. If you're not familiar with the name, it's not that weird, most of the skyscrapers here have nicknames (Cheese Grater, Gherkin etc. - shown above). This is one of the newest and it's infamous for melting things when it was first built (with it's parabolic mirror surface you see here). It has a lovely viewing deck on the top, as well as a bar, a garden (of course) and a couple of restaurants. It's free to get in, you just need to book in advance, queue for about 30 mins and bring photo ID with your ticket. Then the 'standard' metal detector shenanigans. OK that sounds like a pain, but it's worth it I promise.

We booked an appointment to visit this place a while ago and when it finally came time to go the Carl Zeiss Sonnar FE 55mm f/1.8 lens had just turned up. I'd spend a day or so with it, so of course I was itching to take more photos. All but one of the photos you'll see here was taken with it, so I will put details underneath each shot, as well as exposure info, so you can tell which it is.

Above: This first shot was taken from the top of the 'Monument'. It cost £4 to climb this tiny spiral staircase. It's not for the claustrophobic, but I appreciated this higher angle. I photoshoped a crane out on the right side of this image because it was rather distracting.
Below: The next shot was taken from the ruined church - 'Saint Dunstan In The East', which is a beautiful place to visit in it's own right. I will show a shot looking down into here later on.

Zeiss Sonnar 55/1.8 - 1/100th, f/5.6, iso 100 - B+W 093 filter

Zeiss Sonnar 55/1.8 - 1/60th, f/4, iso 200 - B+W 093 filter

Above: From the north of the building you're surrounded by a few skyscrapers. On the right here is the famous 'Lloyds Building'. I love this street for its eclectic mix of architecture styles. It was good before 20 Fenchurch Street was built and now it's even more of a mix.
Below: More older buildings, with some lovely details, on 'Lower Thames Street'. The details you see on this side of the 'Walkie Talkie' are shapes to break up the reflections and make them less damaging from that magnifying curve.

Zeiss Sonnar 55/1.8 - 1/60th, f/8, iso 100 - B+W 093 filter

Zeiss Sonnar 55/1.8 - 1/60th, f/8, iso 100 - B+W 093 filter

Above: Here's a modern buildings on the south east side.

     From Up Top
Here are some shot from inside 'The Sky Garden'. There is quite a big area to move around up here. It has plants beside the steps that go up each side of the room. These steps span three floors (35th to the 37th) and give access to the restaurants and some extra seating.

Sony 28/2 - 1/40th, f/4, iso 160 - B+W 093 filter

Above: This is from the back of the building, on a highest level. The main, open viewing deck at the front is on the lower 35th floor. I switched to the Sony 28mm f/2 lens for a couple of shots, just to show the interior better. This was the only one that I liked. In hindsight I wish I'd taken more from this lens and more colour shots with it too, but I was a little too eager to use the Zeiss lens and get as many samples as possible.

From this point on the images looking down into the city are taken from the main viewing platform, on the 35th floor (looking south).

Below: This first shot shows the 'curvy' little town hall building and H.M.S. Belfast, on the south bank of the Thames.

Zeiss Sonnar 55/1.8 - 1/60th, f/4, iso 400 - B+W 093 filter

     Colour Infra-red Photos
All of the remaining images are taken using the Hoya R25A (red) filter. This is equivalent to about a 590nm converted IR camera. This combination of red light and the entire near infra-red part of the spectrum makes the camera slightly more sensitive to light than 'normal', visible colour and thus gives slightly faster shutter speeds.

Below: This shot looks down into the overgrown church ruins of 'Saint Dunstan In The East'.

Zeiss Sonnar 55/1.8 - 1/60th, f/8, iso 200 -Hoya R25A filter

Zeiss Sonnar 55/1.8 - 1/100th, f/7.1, iso 100 -Hoya R25A filter

Zeiss Sonnar 55/1.8 - 1/80th, f/8, iso 100 -Hoya R25A filter

Zeiss Sonnar 55/1.8 - 1/1600th, f/2.5, iso 100 -Hoya R25A filter

Zeiss Sonnar 55/1.8 - 1/125th, f/7.1, iso 100 -Hoya R25A filter

Above, you can see one of the restaurants in the top right. This was taken from the middle floor. Below, you can better see how the foliage is constrained to the sides of the structure, around the steps.

Zeiss Sonnar 55/1.8 - 1/80th, f/7.1, iso 100 -Hoya R25A filter

Zeiss Sonnar 55/1.8 - 1/60th, f/8, iso 125 -Hoya R25A filter

     Fake Tilt-Shift Photos
These last few images are processed (in Photoshop CC) using hand painted masks to control a 'Lens Blur' filter. The goal is to make these images look like a miniature model, but simulating an unnaturally shallow depth of field.

Similar to the first black & white city photo, this colour infra-red shot highlights H.M.S. Belfast. Although quite subtle, I put the focus on the ship, to help draw the eye to it. Making the mask for this involved some rather fiddly mask painting around the spindly details at the top of the ship.

Zeiss Sonnar 55/1.8 - 1/100th, f/5.6, iso 100 -Hoya R25A filter

Zeiss Sonnar 55/1.8 - 1/125th, f/5.6, iso 100 -Hoya R25A filter

Above: The 'Shard' is pretty much directly south from 'The Sky Garden'. Below and to the left of that is London Bridge station, which is a rail and underground station.
Below: The ikonic 'Tower Bridge, which connects the 'Tower Of London' (old castle), in the north with the 'Town Hall' and H.M.S. Belfast again, on the south bank.

Zeiss Sonnar 55/1.8 - 1/125th, f/5.6, iso 100 -Hoya R25A filter

Below: Here is the mask use to make the above image:

This took about an hour or so to make and is just about good enough to get the effect that I wanted. I could have spent more time masking off more buildings to get the correct values, but it tends to get muddied and rather time consuming after the main subject has been done.

If you've seen real tilt-shift images basically what they are doing is the gradient underneath and not the mask of the building. They can't actually alter the depth of field, only blur the top and bottom of an image. So although they can give a nicer 'lens blur' effect they can't quite do this separation of subjects.

False Colour Infra-red Processing (part 1)

This tutorial shows my workflow for taking an infra-red image from RAW to final, using the 'false colour' technique. The editing will be done in Adobe Camera RAW (ACR) and Photoshop CC. I chose this example image because it has a good mix of clear sky, clouds, foliage and rock. The strong direct sunlight and shadows provide nice contrast and dynamic range. One of the main features of this process is retrieving the blue sky, but this is a trick (is fake). Before I get ahead of myself though, here is some information about the image:

• Settings: 1/125th, f/8, iso 100
• Camera: Sony A7 (converted to full-spectrum)
• Lens: Nikkor 35mm f/2.0 AF-D
• Filter: Heliopan Red (#25)
• Tripod: No
• Area: Stone Circle - Keswick, Cumbria (Lake District), UK 
• Time of Day: Evening, about 45 minutes before sunset

This is the unmodified RAW image. If you're taking infra-red photos I highly recommend shooting in this format if you can. RAW files offer greater flexibility with colours and levels, often resulting in lower noise and better tonal range. This is what a colour infra-red image looks like with the white balance (WB) incorrectly set in the camera. Fortunately editing the RAW file offers the ability to alter the WB values in post production with no loss of quality.

Here is an example of a better WB setting. The 'temperature' at it's minimum value of 2000 brings the red channel much closer into line with the green & blue. It's often still not possible to get it low enough changing this one setting, but don't panic yet.

Dragging the WB Tint value down will help align the green and blue to each other. This will help get a more balanced colour image, but it won't bring much more of the red channel's values down - still not time to panic.

By clamping the values of the green channel it vastly improves the colour balance and it also brings the red channel more into line. This is partially because the values you seen in the individual channels are an absolute, whereas the histogram you see at the top right is a result of the manipulation. To put it another way - we're clamping the 14bit values (16,384 tones) into 8bit (256 tones) in a better way and thus improving the dynamic range.

Clamping the blue channel values will bring the red channel further into line with the other two. With all of the channels potential maximised I'll take the image into Photoshop (CC), but before you open the image and go out of ACR you can do any other edits you wish at this point.

Small tweaks to exposure can be made and gradients and/or vignetting can be added but this will throw out the histogram values a bit. If you do this after the channel tweaks you'll have to come back and re-adjust the clamped values again. Contrast and Saturation adjustments will skew the individual channels however, so larger changes will be needed to bring the values back into alignment, so I recommend getting these the way you want them before doing the channel tweaks the first time.

Now for the 'Flase Colour' technique. This involves swapping the red and blue channels around and for this we will need to add a 'Channel Mixer' adjustment layer. Once added choose 'Red' from the 'Output Channel' drop-down menu and then manually swap the values of the red and blue sliders. Red should be changed to '0' and Blue to '100'.

Now select 'Blue' from the 'Output Channel' drop-down menu and manually swap the values of the red and blue sliders again. Red should now be changed to '100' and Blue to '0'.

To finish off my process I add a 'Hue/Saturation' adjustment layer. I moved the 'Hue' slider until the sky reached a realistic colour (although it can sometimes be fine where it is). I also boosted the Saturation of the entire image a bit, but this will be a very personal taste thing.

If the blues get out of control when you boost the colours you can select blue from the drop-down menu to reduce it's saturation independently.

Although I often make many little tweaks to the sliders in ACR, add gradients and vignetting etc. this will vary greatly depending on the image. Hopefully this covers everything for the basic principal, but if you think I've missed anything or you'd like me to add any other information please feel free to write a comment below.

PS. I will be back soon to talk more about camera hardware and will soon be starting the lens reviews specifically pertaining to infra-red performance. I should be able to test most lenses on the Sony A7, so if anyone has any requests please post a comment below.