Finally pulled the trigger on my upgrade to the Canon S100

[Interceptor121]

Yes the concept is correct you can force shutter speed in Av however in my opinion is easier to force aperture in Tv as that may work easily with all housing including polycarbonate. The aperture with a fisheye housing is a relatively static setting F5.6 in wide angle and F8 in macro

 

[Foxfish]

My camera and housing are on the way, so I can play...I have DSTTL (S&S) compatibe strobe

Maybe I missed something, but to use ttl (particularly DSTTL), I thought the concept was to use CHDK and force the shutter speed to something beyond (above) the abysmal 1/60 and then shoot in aperature priority...adjusting the aperature based on desired scene settings

(this was discussed in the previous post regarding the necessity of CHDK)

Hopefully the TTL script written by Interceptor allowing ttl in M will work, negating the above

What kind of housing did you get and what did you think?

I read the post to mean that you would shoot in Tv mode and adjust the aperture setting suit with CHDK. I suspect that with the S100, CHDK gives you the ability to adjust aperture and shutter speed in both Tv and Av mode while retaining the ability to shoot TTL. Sounds like CHDK for the S95 gave you the ability to shoot TTL in manual mode. Can you confirm this is the case Interceptor121?

---------- Post Merged at 07:39 AM ---------- Previous Post was at 07:34 AM ----------

Yes the concept is correct you can force shutter speed in Av however in my opinion is easier to force aperture in Tv as that may work easily with all housing including polycarbonate. The aperture with a fisheye housing is a relatively static setting F5.6 in wide angle and F8 in macro

Why the need for aperture adjustment when shooting in Tv mode? I've heard that when shooting wide angle with a compact the depth of field is normally pretty good even for low apertures. As you zoom in the camera automatically closes up the aperture.

---------- Post Merged at 07:58 AM ---------- Previous Post was at 07:34 AM ----------

Chanced upon a good thread here on the pros and cons of Tv and Av modes.

http://www.scubaboard.com/forums/canon-corner/423499-canon-s-series-av-mode-performance-lack.html

 

[Interceptor121]

To shoot in TTL in manual with CHDK you need a script - I posted a link to my dropbox where you can download it

For what concerns your second question it depends on the focal length, with my Inon UFL165AD and a magnification of 0.405 at 35mm equivalent am actually at 3mm

Looking at depth of field I want something that when focusing at 1 foot gives me infinite depth of field, this happens at F5.6 approximately
and essentially means that even with the crappy focus of the camera at one foot everything beyond will be automatically in focus and sharp

If I go on shutter speed when the camera is at 35mm it will then select an f-stop of 2.8 for the aperture, this at the same one foot will give me only 2 feet in focus. To obtain infinite I will need to step back at two feet which means my foreground will be darker as the strobe is further away and might not be able to illuminate the subject in front of me

Good knowledge is on DOF Master

I have spent quite some time looking at all permutations that the camera settings can offer and right now I can train anyone to jump in the water at F5.6 1/125 ISO100 with a fisheye lens and a DS-TTL flash and take pretty good pictures with very few adjustments

Have a look at this set Best of St Lucia 2012 - a set on Flickr the subjects are not that great and visibility was around 15 meters sometimes 20 however with this set up and minimum training my partner managed to take a few good shots. Look at the CFWA they are all in DS-TTL
Some shots are in natural light and some in Av (I was checking the camera capabilities for training purposes)

This shot CFWA Diver | Flickr - Photo Sharing! is in Manual with DS-TTL
The other one CFWA Diver Silouette | Flickr - Photo Sharing! is in Av with CHDK forced shutter speed auto iso (the camera chose 250 sigh!)
And this one in full manual again Diver with Camera | Flickr - Photo Sharing! with DS-TTL

You may or not like the exposure that is set by the photographer however absolutely everything is in focus zoom in and you will see (with the limitation of the ISO 250 that is a bit noisy) if this was shot in shutter speed the camera would have chose F2.2-F2.8 and the diver in the background would have been blurred

Having the camera to focus so easily and a high shutter speed pretty much just leaves the photographer with the choice of subject and composition eliminating unnecessary time to adjust too many settings. Of course you need the equipment...

 

[Foxfish]

Plenty to think about here and try out. Thanks Interceptor121.

 

[Interceptor121]

I am thinking about some webcasts...any takers?

 

[Layla]

YES!!
Who needs a webcast .... I'm actually just up the road from you

I am thinking about some webcasts...any takers?

 

[Interceptor121]

North Carolina??

YES!!
Who needs a webcast .... I'm actually just up the road from you

 

[Foxfish]

I looked at the chart for the S95 at 1 foot and cannot see how increasing the fstop makes much difference to the depth of field. Maybe I'm missing something. A webcast that discusses this and the improvement in depth of field with higher fstops would be of interest.

Here is a photo I took on land using the principles mentioned above. ie. I adjusted shutter speed till the background lighting was just right and then used the internal flash to light the foreground picture. Shutter speed was 1/15, aperture 2, equivalent focal length was 26 mm. This was shot in raw, converted to jpeg and then compressed for uploading.

 

[Interceptor121]

You need to look at the real focal lens no the equivalent and apply the magnification of a fisheye lens this brings the focal lens to 3mm
In your picture only the foreground is in focus, you don't want that for cfwa

 

[Foxfish]

Here is another one playing around with slow exposures for the background lighting as it got dark and to blur tails lights as well as lighting the foreground with flash. If I can get this to work underwater it shows promise. Background blurred because of long exposure.



---------- Post Merged at 06:57 AM ---------- Previous Post was at 06:54 AM ----------

You need to look at the real focal lens no the equivalent and apply the magnification of a fisheye lens this brings the focal lens to 3mm
In your picture only the foreground is in focus, you don't want that for cfwa

Consider change in depth of field with variation in aperture for an S95 with say an equivalent 28 mm focal length. It doesn't appear to make much difference on the chart.