Seacam Prelude for the Canon 60D review


For quite a few years, the virtues of APS-C versus 35mm has been discussed with great vigor on Wetpixel.  Being a self-confessed pixel peeper, I’ve always liked the resolution and ISO performance of 35mm sensors.  Shooting macro with 35mm sensors can be, ahem, more than challenging!  The shallower depth of field and the need for extra focal length to achieve the same look means heavier and bulkier housings.  That is why I stuck with the 1D series for so long.  The 1Ds series is 35mm and has the resolution, while the 1D series is APS-H which helps with macro and depth of field. APS-C cameras promise even more.


Damselfish in a hole. 1/160 f13 ISO100 FEC-2/3 ETTL. 100 f2,8 Macro with 25mm tube

Another point was the fact that with the Seaflash 150, I had ETTL for macro, something I missed since my Heinrich converter went missing a couple years back.  So the macro test was something I was looking forward to, especially since I was at Seraya, a hotbed for small macro subjects.

Armed only with the 100mm f2.8L and older 100mm f2.8 Macro, I also added a Kenko 36mm extension tube for a little bit of 1+:1 action since Seraya was just into new moon phase and that meant the little guys would be out after a few weeks of spawning last full moon.

At 100mm (35mm equivalent), the lens gives the field of view of a 160mm lens at minimum focus distance. The extra magnification and depth of field allows more flexibility in shooting macro.  I was getting right up close and personal with animals, and the depth of field keep things in focus.  The S10 viewfinder was very nice with judging focus or aiming AF on target.  With the 35mm cameras, I always try to shoot f22 or higher.  I just went on an f22 spree for the first macro dive.  But without the ability to check focus, I had no idea what the result was.  It was then that I harshly rediscovered photophysics again in the form of diffraction!


Note the loss of resolution on the left at f22 vs f13 on the right.

The softening or loss of resolution occurred in every picture I shot at f22 and above.  Only that night did I see the softness on the computer. It’s not really visible if the detail isn’t small, such as when the subject fills 3/4 or more of the frame.  It only showed when the image had very fine detail like sand. Obviously even with 18mp, cropping was out of the question, but then again it looks decent if you look at it at less than 33% magnification.  I was surprised.


Thecacera Sp nudibranch. 1/100 f22 FEC 0 ETTL Av Mode. 100 f2.8L Macro with 36mm tube

Lesson learnt, I dropped 2 stops or more, sticking to f11-13 and forcing the AF to get the right spot on the subject since I couldn’t use manual focus as I had forgotten my focus gear.  Fortunately, the AF on the 60D worked very well for macro overall.  There wasn’t much AF searching, except in low contrast and low light conditions, where a focus light is essential.  Subject acquisition was quick and accurate.  This was especially true when using the center AF point. I didn’t once miss the spot where I wanted the focus to be.  In AI Focus AF mode, the AI would occasionally choose the wrong point to focus on:


Tambja Morosa AI Focus AF Mode on the left/AF-SERVO mode on the right
1/125 f13 ISO100 with ETTL -1/3 stop. 100mm f2.8L Macro with 25mm tube.

Here you have a sequence where the AI Focus followed the body of the nudibranch but not the more contrasty head.  It’s on a minute issue that is visible when looking at 67% or higher that’ll you’ll see the head is out of focus until the 2nd frame.


AI Focus AF Left/AF Servo Mode Right

Shooting in Macro Mode

Macro mode worked well for pretty static objects like frogfish and blennies.  One does lose a creative control over the background lighting because it uses a lower shutter speed and stays in ISO400 while keeping the aperture closed above f11.  Like Full/Creative Auto mode, it will apparently drop ISO once 1/250 and the max f stop can’t handle exposure with flash.  So while ETTL in Macro Mode will take a well-exposed shot, the creative lighting situations are still best done in Manual Mode.


Ornate Ghost Pipefish eggsack. 1/160 f13 ISO400 FEC -2/3 ETTL. 100mm f2.8L Macro with 25 mm tube

The S10 viewfinder was a bit strange for me since I normally use either the S45 or S180 for macro.  The 10° tilt is a mixture of both. The tilt view does have its advantages.  The line of sight is a little higher, so you can see a bit more of the housing on what is coming. This would be a great advantage in situations where you need to see where the subject is approaching from etc.  Furthermore, for macro, while it’s not a 45° tilt, the 10° does help a bit when you want a lower perspective shot and can’t get down that low to frame.

The housing performed well for macro.  The naturally ergonomic placement of the AF-ON lever and the sensitive feel meant easy shooting with Macro Mode and focusing.  There were a few times where the limited controls required a bit more work.  Macro dives can be especially demanding for menu changes.  For example, while shooting close macro, if I wanted to change the AF point to focus on an off-center subject, I either used the Q menu or try to focus and recompose, where I lost a few shots because the subject had moved.


Blenny in a pipe. 1/250 f13 ISO200 FEC-1 ETTL. 100 f2,8 Macro with 25mm tube

The biggest issue for macro is focus.  As noted before, the housing doesn’t have access to the +/- magnification buttons, so focus check is not possible, nor is histogram checking during playback.

Other than that, macro shooting with the Prelude left nothing else to be desired.  The ETTL from the Seaflash was excellent with exposing subjects, in both Manual and Macro Mode.

Next: Video mode