Since I embarked upon my Somerset Towers project, I’ve visited over a dozen churches across the country to photograph them with my Horseman 980 view camera. It’s barely made a scratch in the project, but I have learnt a lot already.
View cameras are appropriate for architectural photography because they allow the photographer to capture a tall church without distorting it and making the tower appear to lean. However, a major drawback of view cameras is the smaller choice of lenses, especially towards the wide-angle end of the range. The widest lens available for my Horseman 980 has a focal length of 65mm, which on the 6×9 format gives you a diagonal angular view of about 76°. Lots of the Somerset Towers are set in small churchyards with lots of trees, so it simply isn’t possible to move further away from the church to fit it all in.
This leaves me with no choice but to go wider and use a lens with a shorter focal length, which in turns means moving to a different format and giving up my view camera for some of these shots. I made a few notes about my collection of lenses to see which ones were wide enough for the job. However you can’t simply compare the focal lengths – you also need to know the size and aspect ratio of the negative format you’re using. You can’t simply compare the size and crop factor of those formats without compensating for the aspect ratio.
This diagram shows various common film formats, ranging from 6×9 (medium format view camera) down to APS-C (digital SLR).
For the purposes of my project, I want to use as large a film format as possible, so if 6×9 is not possible due to a poor choice of lenses, I’ll have a look at my 6×7 equipment. Failing that, I’ll have to resort to 35mm equipment. Let’s have a look at my widest lenses on each format. Lens specifications only usually quote the diagonal field of view but if you know the dimensions of the film format, you can use some trigonometry to work out the horizontal and vertical angles too.
|Lens||Format||Diagonal angle of view||Horizontal angle of view||Vertical angle of view|
|Horseman Press 65mm f/5.6||6×9||76°||66°||47°|
|Mamiya Sekor C 50mm f/4.5||6×7||84°||70°||58°|
|Canon FD 28mm f/2.8||35mm||75°||65°||46°|
|Canon FD 24mm f/2.8||35mm||84°||74°||53°|
|Canon FD 17mm f/4||35mm||104°||93°||70°|
To illustrate my point, you can see that both the Mamiya 50mm and the Canon 24mm lenses offer the same diagonal angle of view – but because the 6×7 format is squarer than the 35mm format, it offers more vertical coverage and less horizontal coverage.
Given that most of the churches are too tall for the frame rather than too wide, I will use my Mamiya RB67 with its 50mm lens for the shots that can’t be done with the view camera. I can use the Canon FD 17mm as a last resort!