Another 10.5 FE shot..

Interesting!

The reason that film is so good at capturing bright sun rays and dark shadow details is that it has a "chemical curve" that is much different than the way a digital sensor pixel records light. I can't think of a way to demonstrate what a film curve might look like (without using a whiteboard).

But I figure if film can do it, as long as we don't oversaturate the sunball, perhaps we can do it w/ curves of our own. Of course it doesn't work as well as film which applies the "chemical curve" DURING the exposure.

Here's a crappy photo with a sunball that I just found on my HD. I developed the RAW file to preserve the tightest "best" sunball I could get:

It's shot in blue/green water, f22 @ 1/125th with strobes on full.

I applied a curve to it where I tried to bring up the shadows but "locked" the highlights:

You'll see that I overlaid the curve on the photo so you can see what I did.

It doesn't look good I'll admit it (the Fuji green doesn't help), but it demonstrates what I'm talking about. I'm wondering if anyone with a good sunball in their photo (Ahem Rand, Ahem Herb) might try something similar and see if this technique actually works or not.

Am I making any sense?

Cheers

James

Thanks for supplying the Curves box on that one James, gives me some things to mess around with post process. Mind you i want to go the other way, lock my blue and black and bring the exposure down on the sun. Will mess around with locking curves on that eagle ray shot and see what i can come up with.

In the meantime, here is a great example of a sunburst on film from a few years back. Taken about 60-70 feet, about f18 (you can do that on a nik v too) and shutter of 90. Also around 830am

Ok, here's one with a similar adjustment. Comparing it to the original, it seems the colors have been muted. But, again, each shot is taken under different circumstances and frankly, the exposure % variables probably could form an astronomical mathematical equation.

I chose this one as an example of what Alex had mentioned earlier, that a sunball shot deep, in this case 100' (33m) is knocked down considerable by the water column.

My attempts with the D70 have been with the 10.5. My next will be with a Sigma 16mm. I'd like to fill the frame more with foreground which can help with the black water issue. Especially on the sides of the frame.

Note how the Anemone fish chose this precise moment to dissapear...

Thanks again for all the input. I find this a most fascinating thread.

Rand

Rand, that second shot of yours is incredible. I'm loving the colors, composition and sunburst. You got it all going on in that one!

Hi Rand: sorry to get off topic, but for your future ID reference, that brown coral that looks like an anemone is a Sarcophyton sp. Clownfish sometimes host in them when there's not an anemone available. The coral has no sting, and no mouth in the center of the disk.

Cheers

James

I'm not much with the Id's that's for sure. And actually, I don't think there were any fish around that anemone really. I like the shot with both corals and anemone.

Thanks for the compliment divemaven.

Rand

Hope I didn't sound too "prissy" I was just trying to help w/ the coral ID. I too like the shot very much and wish I had some like this from the fiji trip.

Here's one of my obscured sunball shots:

Nikon 12-24

And a sun just out of the frame shot w/ the 10.5:

And here are a BUNCH of those big toadstool leather (Sacrophyton sp) corals:

Cheers

James

I know a number of you have seen this shot, but the 20D didn't seem to do to badly in this case...

1/400, f/18, 18-55mm kit lens

Granted, this was only 10ft depth, so not sure how increasing amounts of water are going to affect it. The center is very much overexposed, but the radius still seems to retain the same effect as other bursts...don't know if this was just a lucky event or is indicative of the general abilities of the camera. If vis is good this weekend, I'll be out shooting WA kelp forest, so we'll see what comes of that...

~Matt Segal

I know a number of you have seen this shot, but the 20D didn't seem to do to badly in this case...

 

Granted, this was only 10ft depth, so not sure how increasing amounts of water are going to affect it. The center is very much overexposed, but the radius still seems to retain the same effect as other bursts...don't know if this was just a lucky event or is indicative of the general abilities of the camera. If vis is good this weekend, I'll be out shooting WA kelp forest, so we'll see what comes of that...

 

~Matt Segal

Actually, I think shallow shots are the most difficult because of the brighter sun. This is really well done! I noticed the 1/400 shutter speed. Did you use your strobe? Does the 20D sync at 1/400 ? The DRebel can sync up to 1/320 even though it's rated at 1/200. I'd be intereted to know if the 20D with an improved shutter can sync at 1/400.

James, I think the second shoot has a lot going for it. Really colorful.

Matt's shot is really nice. The exposure for the sun is great. Would have loved to see the Jelly framed in front of the sun for a cool back lit shot. And FWIW, my best or maybe I'll just say favorite sunshot was at 17' so maybe shallow is good.

Rand

In this shot, I was using (2) DS-125s at -0.5 (controlled in manual mode on the back of the eTTL2 housing). What I have been wondering for a little while now however, is how much, if any, impact those strobes made in the shot, as compared to the overwhelming natural light.

With regard to flash-sync, I noted the following in my 20D + Ikelite eTTL2 housing report (found on my site):

In eTTL2 mode, the 20D always reverts to no faster than 1/250 when the photo is taken. In manual strobe mode, however, the 20D syncs up to 1/320 before black banding occurs (this was apparent from 1/400 onwards).

(the modes referring to the different settings of the eTTL2 controller built into the housing back)...So apparently the 20D and the Rebel match up with regard to manual strobe settings, with the 20D holding a slight edge in TTL strobe-sync (not much of an issue as majority of any TTL work would be macro where 1/200 or 1/250 really won't make any difference)...

I'll continue to experiment...

~Matt Segal

The D70 will "normally" sync to 1/500. If a flash is attached, the camera will not allow a shutter speed faster than 1/500 to be selected. Unless...the hotshoe connector is moved back enough to break the circuit to the camera that tells it a flash is attached. Then you can sync as fast as you care to. And because of the electronic shutter, no black bands appear. There of course is the debate of how much flash can be utilized at those speeds but that's not my concern here at the moment.

I gather the 20D will allow higher sync speeds to be dialed in. Just that at some point, the black banding will be visible.

All this is prelude to what I've found of interest concerning a better blue background. And it goes back to Alex's test shots and the better blue he had in the 1/2000 shot @ f5.6. I'd like to try that approach of using even wider apertures and fasther shutter speeds to see how that might affect the water color. I can see a difference in the blues between his shots. Hopefully, it's not a result of a difference in post processing...

Rand

All this is prelude to what I've found of interest concerning a better blue background. And it goes back to Alex's test shots and the better blue he had in the 1/2000 shot @ f5.6. I'd like to try that approach of using even wider apertures and fasther shutter speeds to see how that might affect the water color. I can see a difference in the blues between his shots. Hopefully, it's not a result of a difference in post processing...

 

Rand

My best guess is that you won't see any difference; you'll get the same result for the same exposure whichever combination of shutter and aperture you choose. I just noticed, the four shots Alex posted are not the same exposure. They needed to be: 1/2000, f5.6 ; 1/1000 f8 ; 1/500, f11 and 1/250, f16 to be the same.

You can bring out some of the blue in dark places with post processing. How noisy that is will depend on the sensor in your camera. This was the point I tried to make in this long... thread back here:

http://wetpixel.com/PNphpBB2-viewtopic-t-7...9-start-0.phtml

I

 

In eTTL2 mode, the 20D always reverts to no faster than 1/250 when the photo is taken. In manual strobe mode, however, the 20D syncs up to 1/320 before black banding occurs (this was apparent from 1/400 onwards).

 

 

~Matt Segal

So much for the new and improved shutter. Looks like the net change from the old one is that it got louder. That wasn't quite fair. The shutter in the DRebel probably can't do 5 frames per second.

That is a great Jellyfish shot Matt, perhaps you were inspired by my May/June contest winner?? Just kidding

Very glad to see how well your Canon held the light on the sun, its a touch powerful but i think it works quite nicely. It doesn't have that warped look i get with mine.

Seeing as i am the one with more access to nice blue water than most of you, and now that i have the 12-24, i will get out there in the next week or so and run some tests and post em.

I've done a bunch of tests up to 8000 with both high and low apertures but deleted em all. All of those done without strobe obviously.

Rand, whats this about overriding the synch speed? Just don't put the hot shoe all the way on? Give me a few more details if you could and then i can try that.

Hi Mike,

Two ways to do this, one is to tape over the contact and I think Alex knows or someone here knows which one it is. I just push the connector into the hotshoe and then gently pull it back until I feel/hear a click. That's it.

It took awhile at first to get it in the right spot. When I heard about this and before I acquired the "touch", I'd keep turning the shutter dial while slowly moving the hotshoe connector back (or forward) until the shutter would go past 1/500. Then it's positioned correctly.

Look forward to your results.

Rand

To make a flashgun fire you only need two connectors - the trigger and ground. The trigger is the large connection in the middle of the hotshoe and the ground is the edge of the hotshoe. Blocking the other three has always worked for me. Alex

Great thread!

Its will be very interesting to see actual result of post processing with the curves as James suggested.

Hope next week to test it.

Promised I would put up a sunburst-esque image taken with the 20D from my recent (this last Saturday) local diving...there's a few more I haven't edited where the sun rays look like electric fire, but here's a quick example...

20D, 1/320, f/22, ISO100, 18-55mm kit lens @ 33mm

~Matt Segal