Subal C10, first impressions

Hi Folks,

Tried out the Subal C10 housing for the Canon EOS 10D in a swimming pool on Friday night:

To reiterate what I've said earlier:

1) It's a Subal, the fit and finish is outstanding. Controls have a nice weighted feel, the shutter release is very smooth.

2) The rear dial is a bit hard to reach if you're using the supplied handles (now made of some plastic instead of the earlier aluminum)

3) The "*" button is also too far away for my hand (and I take XL gloves) to reach comfortably....but I use the shutter button for AF so it's not a relevant issue for me.

4) If you're using the Ultralight BA-SU dovetails, they will only work on the right side strobe mount. To position and height will either block the rotation of the mode dial or won't let you mount the BA-AD dovetail. ULCS does have the BA-SA, BA-SV balls that bolt onto the mounts or the BA-TG which will mount on the Subal T-groove mounts.

5) If you have zoom gears for the older film housings for the EOS film bodies, they will not work with this housing, you will need to purchase new gears.

6) The 15mm fisheye does not vignette if you use the DP-SWC domeport (6" dome). Corner sharpness seems good as we shot vertical slats in the pool and the lines stayed sharp

7) The 16-35L does need the +4 diopter to work....corner sharpness is basically indistinguishable from the center....

8) A short zoom (I'm using the EF 28-105) behind the FP-90 will be my primary lens, with the lens racked out to 105 and with the addiition of Woody Mayhew's push on diopter, I was able to fill the frame with a 1" subject... horizontally! I will be reserving my 90 Tamron for full frame shots of pygmy seahorses from now on.

9) I don't miss TTL, the instant feedback of digital will give me the option of adjusting my lighting either through strobe placement or shutter speed, aperture and ISO changes will be secondary adjustments as if I don't want to change DOF or noise levels.

10) I will keep my film Subal for now only because I want to use my 16-35L at the full 16mm. I can mount both zoom gears for the 16-35L at the same time as the C10 uses the forward half of the zoom ring and my CE-5 uses the rear half of the zoom ring.... =)

That's about it folks, I'm taking my new housing to the Philippines next week for 2 weeks of shooting, I'll hopefully have some images to post by the end of Nov.

Safe diving!

Stu

8) A short zoom (I'm using the EF 28-105) behind the FP-90 will be my primary lens, with the lens racked out to 105 and with the addiition of Woody Mayhew's push on diopter, I was able to fill the frame with a 1" subject... horizontally! I will be reserving my 90 Tamron for full frame shots of pygmy seahorses from now on.

Really? That would be a 1:1.13.

Canon lists the minimum focus distance at about 1.5 feet and the maximum magnification at 1:5.3. The woody's diopter is not that strong underwater.

By contrast, my Nikon 24-85 focuses to 1.2 feet and offers 1:4.7. With a woody's diopter I can get 1:3 pretty easily but 1:2 is practically impossible.

My 70-180 is a true macro lens capable of 1:1.33 at 180mm. With the woody's diopter it can get to about 1:1.15 but not all the way to 1:1.

I'm curious to know how a non-macro lens can offer such incredible magnification with simply a weak diopter. It fully matches the performance of my 70-180 yet offers a 28mm end?

Hmm, gee Craig, all I did was take a picture of something of a known size and oh my gosh, it came out! I didn't take to using no math or nuthin!

I made fun of all these guys who took ruler pics on DPReview and other sites, but I ended up doing it myself. So, I fibbed a bit, the measurement was a tad over 1 1/8th of an inch.

B)

Stu

I'm not a Canon-man (although I do have an Digital Ixus II) so I may be wide of the mark here. Speaking to Eric the other week (while we were both looking at the C10) he was saying that the key to the * button was that you have to be able to reach both it and the shutter at the same time. Is that the problem?

Looking forward to seeing your shots from the Philippines.

Alex

Hmm, gee Craig, all I did was take a picture of something of a known size and oh my gosh, it came out! I didn't take to using no math or nuthin!

 

I made fun of all these guys who took ruler pics on DPReview and other sites, but I ended up doing it myself. So, I fibbed a bit, the measurement was a tad over 1 1/8th of an inch.

 

B)

 

Stu

1:1.27 is still remarkable. What was the focus distance and the working distance after you include the port? My 24-85 does 1:2 but with the port the working distance is too small to achieve it.

Hi Alex, Craig,

to answer your questions:

The "*" button is prefered by some shooters for AF lock. So the sequence to shoot with the"*" button is:

1) aim at subject and hold shutter button down halfway (this locks exposure)

2) press the "*" and hold button down to start AF

3) compose shot

4) fully depress the shutter button.

I suppose this would be helpfull if you and your subject were static and didn't move around. But I'd rather re-focus each shot anyway.

Craig, I would estimate that the test target was about 6-8 inches from the front of the port without the diopter and down to 5 inches with the diopter.

Stu

I've never considered it, but the flat port magnification should increase the apparent magnification of the lens by a factor of 4/3. That means your actual magnification is a bit more reasonable. Still, it's better than my 24-85 but that's possible.

Canon lists the minimum focus distance, depending on the model, at 19" and 20". Are you using a current model Canon lens? If so, it appears your lens performs well beyond the Canon spec. If they all do that and are sharp, I'd think all digital canon users would want to use it. Does your lens have a macro setting?

The lens has a 1.5 ft min. focus distance. So, about 1 foot from the front of the lens. All I can say is that with my holding the camera to my face and my left hand extended fully forward holding the ruler, I was able to acheive focus lock....taking a rough measurement, that's about 18". So subtract camera and port (about 9"-10" combined), then it's not that far fetched....and as you say add the difraction and resulting magnification of the flat port adds 25%.

My 28-105 is the version 1, it's about 7 years old.

Stu

Canon specifies a maximum magnification of .19 (about 1:5) at the minimum focusing distance of 1.6 feet. You are achieving .59 (about 3x that rating) with roughly a +1 diopter. What I'm trying to understand is where the huge boost is coming from. My Nikon lens is specified to perform slightly better than yours, yet it doesn't come close using the same diopter.

According to spec, your lens without the diopter should produce a field width of ((36mm / .19) / 1.6) *.75 or about 3.5 inches. Is that the case or are you focusing much closer than the rating?

Hi Alex, Craig,

 

to answer your questions:

 

The "*" button is prefered by some shooters for AF lock. So the sequence to shoot with the"*" button is:

 

1) aim at subject and hold shutter button down halfway (this locks exposure)

2) press the "*" and hold button down to start AF

3) compose shot

4) fully depress the shutter button.

 

I suppose this would be helpfull if you and your subject were static and didn't move around. But I'd rather re-focus each shot anyway.

 

Craig, I would estimate that the test target was about 6-8 inches from the front of the port without the diopter and down to 5 inches with the diopter.

 

 

Stu

Actually, I do this quite different. I usually:

1) aim at the subject and tap * button to focus

2) recompose, and shoot.

3) shoot again, and again, and again (no refocus)

Since I shoot on manual, taking an exposure reading isn't necessary.

It's the perfect compromise between manual and auto-focus.

I believe that's the way Craig has his D100 set up as well - or it was when we were testing out the Jonah housing.

Cheers

James

I've never shot with the "*" button underwater. But I have used it when shooting flight shots of birds.

Craig, I don't have the specs of the lens, but I'm simply relating to you what I did. OK? I deleted the images from my CF card or else I'd have posted them for you to look at. I can't explain why there is that discrepancy.

I do think that the diopter from Woody is rated higher than a +1. I think it gives a 1.2x magnification.

s.

The woody's diopter is just a diopter, and when used underwater its strength is only 1/4 that of air. I estimate it is a +1 only because it would be +4 in air for that to be the case. I don't know how to interpret 1.2x. I think it's a made up number.