The Big ALPA FPS Shutter Memory Game

Posted July 14, 2014

Reposted from http://www.alpa.ch/en/news/2014/fps-shutter-memorygame.html

Customers recently asked which shutter is less prone to vibration – the Copal or the FPS focal plane shutter – as they never run into a visible issue when using their ALPA 12 FPS. We did some fun testing. Find out yourselves with our FPS shutter memory game.

The test was set up like a standard photographic situation (indoor, sets A/B) on a Gitzo GT 3541L carbon fibre tripod on an ALPA/Linhof Micro 3D head. Nice and as sturdy as you would expect from pro/semi-pro grade gear… but none of the really, really heavy duty gear for the studio. Details for set C/D (outdoor at infinity), see below.

For all tests the ALPA 12 FPS, Schneider Apo-Digitar 5.6/150 mm and Phase One IQ 180 was mounted on top of the ALPA/Linhof Micro 3D and always three images were taken in a row (three with the FPS shutter and three with the built in Copal 0 shutter – the next image was triggered always after the ready beep of the back). The triggering was done either via a cable release and the ALPA Sync Release trigger or the electr. trigger for the ALPA 12 FPS. Everything was taken from our demo stock without further selection.

We choose a sequence of 3 images as every user handling could potentially influence the result. So this also should be evened out. For the details of the specific shots have a look at the respective section. All images have been processed via Capture One Pro 7.2.2 without sharpening. For the sharpened versions a standard Photoshop selective sharpening got applied as well as the exposure correction in order to make them uniform across all selections. Some of the views are unsharpened for those who like this view better.

How to play the game?

All six shots of a set have been opened in Photoshop and the 100% view for all the portions was synchronized. Then we took a screenshot. This should represent the real pixels best. Download the ones you would like to examine and either put them in an order from “sharpest” to “least sharpest” or just mark them with “F” for focal plane shutter and “C” for Copal shutter if you prefer. The solutions/results are always shown in the form of

C F C

F C F

and the like. For the results see the ZIP file at the end of this article. Now, have fun, it is just a game!

MICROSITE OF THE ALPA 12 FPS

Indoor

Equipment as described above. The distance to the shelf was 1.90 meters. Only ambient light, tethered to the computer.

	Set A	Set B
Exposure	1 sec	1/4 sec
Aperture	f11	f8
ISO	35	100
Latency	normal	zero
Filters	no	no

Set A1

ALPA Shutter Test – A1 unsharpened

ALPA_FPS_Shuttertest_A1_us.png / 4.8 MB

ALPA Shutter Test – A1 sharpened

ALPA_FPS_Shuttertest_A1_s.png / 5.6 MB

Set A2

ALPA Shutter Test – A2 unsharpened

ALPA_FPS_Shuttertest_A2_us.png / 4.3 MB

ALPA Shutter Test – A2 sharpened

ALPA_FPS_Shuttertest_A2_s.png / 5 MB

Set A3

ALPA Shutter Test – A3 unsharpened

ALPA_FPS_Shuttertest_A3_us.png / 5.1 MB

ALPA Shutter Test – A3 sharpened

ALPA_FPS_Shuttertest_A3_s.png / 5.8 MB

Set B1

ALPA Shutter Test – B1 unsharpened

ALPA_FPS_Shuttertest_B1_us.png / 3.7 MB

ALPA Shutter Test – B1 sharpened

ALPA_FPS_Shuttertest_B1_s.png / 4.2 MB

Set B2

ALPA Shutter Test – B2 unsharpened

ALPA_FPS_Shuttertest_B2_us.png / 5.1 MB

ALPA Shutter Test – B2 sharpened

ALPA_FPS_Shuttertest_B2_s.png / 5.8 MB

Outdoor Long Exposure

Equipment as described above. Fix mounting on the concrete on a 10 cm connector and the ALPA/Linhof Micro 3D. The distance to the horizon was some 5,500 meters. A “real” infinity target was chosen because of the maximum effect of vibration should be visible as displacement in the target area. The 1/125 sec for Set D was chosen as this is the shortest shutter time where the shutter is completely opened and no scanning effect of the focal plane slit is to be expected. It was rather hot (for some observations, see the end of the article) and quite a bit windy! Please also mind the considerable deterioration of quality due to the ND filter stacking (explanation see below)!

	Set C	Set D
Exposure	1/4 sec	1/125 sec
Aperture	f11	f11
ISO	50	50
Latency	normal	normal
Filters	ND 4x + 2x	no

Set C1

ALPA Shutter Test – C1 sharpened

ALPA_FPS_Shuttertest_C1_s.png / 2.5 MB

Set C2

ALPA Shutter Test – C2 sharpened

ALPA_FPS_Shuttertest_C2_s.png / 3.2 MB

Set C3

ALPA Shutter Test – C3 sharpened

ALPA_FPS_Shuttertest_C3_s.png / 4.1 MB

Outdoor Short Exposure

Set D1

ALPA Shutter Test – D1 sharpened

ALPA_FPS_Shuttertest_D1_s.png / 3.2 MB

Set D2

ALPA Shutter Test – D2 sharpened

ALPA_FPS_Shuttertest_D2_s.png / 2.6 MB

Set D3

ALPA Shutter Test – D3 sharpened

ALPA_FPS_Shuttertest_D3_s.png / 3.9 MB

Set D4

ALPA Shutter Test – D4 sharpened

ALPA_FPS_Shuttertest_D4_s.png / 4.2 MB

ND Filters and hot air flickering

Two observations were quite striking as always:

1. Atmospherical and meteorological effects like hot air flickering over a city’s rooftops (e.g.) and haze (in this case the lake) can influence an image completely or partially.

2. The influence of whatever glass you put additionally in front of a high resolving lens is astonishing. Both images were taken at f11. Even if you subtract a potential smearing by the above effects the difference in sharpness is self-explanatory.

We took these two effects as one can fight against the first (at least the haze part) with a polarizer but also this additional glas will deteriorate the overall resolution. At the end the photographer has to decide what is the lesser of two evils.