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bmorescuba

Member Since 12 Jun 2009
Offline Last Active Today, 12:49 PM
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Topics I've Started

YS-D1 Cutoff Issue

25 July 2014 - 06:25 AM

Hi Experts,

 

I recently got back from a trip to Kaua'i. I had a bunch of new (well, used but new to me) gear including a Sea & Sea YS-D1 strobe. Unfortunately, my plans for a closer, less exotic trip to practice with the new equipment got scrapped so I had to practice while in Kaua'i. In short, in many of my shots the strobe coverage was cut off for 1/4 to 1/2 of the exposure. It's a very artificial cutoff - I'm sure my strobe positioning was not good for all shots, but this seems like something different. The problem did not happen with all shots, only some. I couldn't identify what conditions were causing it for some shots and not others. Distance to subject and relative strobe position seemed to have some influence but I couldn't pin it down. I saw it in portrait and landscape shots. I usually shoot macro with the strobe above the housing, but I also saw it with the strobe moved to the left of the housing.

 

Equipment used during issue:

Canon 550d, Canon 60mm Macro Lens, Sea & Sea RDX-550d Housing, Sea & Sea RDX Standard Port, Sea & Sea YS-D1 strobe (1)

 

I have previously shot with a single YS-110a strobe and did not have this issue. When I shot with the YS-110a, I always used the diffuser. I also used the Diffuser 100 with the YS-D1 and I'm wondering if this is the issue. Unfortunately, I didn't come up with this theory until the very last 15 minutes of my last dive, so I didn't have time to really verify if removing the diffuser made the issue go away.

 

Examples attached:

d1issue1 - more than half cutoff

d1issue2 - portrait example

d1issue3 - 10% cutoff, but still present

 

Thoughts? Thanks.


Mixed Sea & Sea Strobes

06 March 2014 - 08:43 AM

I've been shooting with a Canon 550d in a Sea & Sea RDX-550d housing. Up until now, I've been doing mostly macro using a single Sea & Sea YS-110a strobe. I'm now cobbling together a used setup so I can shoot the Tokina 10-17 as well. If I can find one at a reasonable price, I'd like to add a second strobe, preferably a Sea & Sea YS-D1. Will there be any issues with this mixed strobe setup? As far as I can interpret the Sea & Sea charts, it should all work. I sometimes shoot in manual, but I often rely on TTL and would like for that to continue to work. The housing has 2 FO ports, so that part should be easy.

 

Thanks!

 

(and if you need to get rid of a YS-D1 for any reason, just let me know...) 


FS: Nocturnal Lights SLX 800

19 January 2014 - 07:52 PM

For Sale:

 

Used Nocturnal Lights SLX 800 video/focus light

 

Includes:

Original Box, Instruction manual, Extra O-rings

Light and the original 2 sets of reflectors - narrow and wide

1" Ball Adapter ($30 accessory) (for ULCS-type arms)

 

The Wide reflectors are installed. All hardware needed to swap for narrow is included.

 

Never been flooded, works with no issues. A little too big for my travel needs.

 

Price: US $75. Includes Priority Mail USPS shipping to US address. Outside US - must pay actual shipping cost.

 

Paypal only.

 

Manufacturer Info: 

http://www.nocturnal...dive-light.html

 

 

 


TTL/FEC Theoretical Question

18 January 2014 - 07:07 PM

I'm relatively new to strobe shooting, so I mostly stick to TTL. I'm guessing the ultimate answer to this question is: use Manual instead of TTL. Nonetheless, there is a theoretical issue I've been grappling with since I started researching strobe shooting and reading as much as I could.

 

As far as I understand things, the idea of TTL in an optically triggered external stobe is something like this: the camera figures out how much flash to use and fires the on-camera flash. That flash is completely blocked by the housing, only traveling on the fiber to the strobe, which is then able to see how much flash the camera felt was needed and set the output of the strobe to match.

 

However, there is a lot of advice for improving on-camera flash recycle times which suggests decreasing the output of the on-camera flash. On my camera I believe this would be called Flash Exposure Compensation (fec). This is entirely logical. Since the on-camera flash is not illuminating anything, why not set it to as low as possible while still triggering the strobe. This should save battery life and improve recycle times.

 

What I don't get is this - how could dialing down the fec not affect the TTL communication between the on-camera flash and the strobe? It seems like you're manually overriding a camera-set value. This would in turn yield inaccurate TTL results.

 

Perhaps I'm missing something very basic? That's very, very possible... 

 

550d/Sea&Sea RDX 550d/1x ys-110a


Backscatter? Circles

09 December 2013 - 08:39 PM

As I begin to get a little beyond the basics, there is one mystery which keeps popping up again and again. The attached files illustrate what is hard to explain.

 

Shooting Setup:

Canon 550d

S&S RDX-550D housing, standard flat port

60mm Macro lens

1x S&S YS-110a strobe

 

When processing my raw files in Lightroom, I often find mysterious large circles which are lighter than the surrounding area, especially in dark sections of the photo. Perhaps they are everywhere in the photos and only visible in darker backgrounds - not sure. These are distinct from normal backscatter. Sometimes i can just edit them out, but I'd really like to know why they occur in the first place. Are they a different type of backscatter? Are they because of unclean glass somewhere in the light path? Is at a fundamental flaw in my technique? I have seen them in others' online galleries, so whatever causes them, it's not unique to me.

 

"20131120-IMG_9966.jpg" is a hawkfish photo I was editing today when I saw the circles.

"circ1.jpg" is a crop of that pic with some of the mystery circles underlined (it's also been altered to make them more obvious)

 

I would love to know what causes this phenomenon and, more importantly, how to avoid it in the future.

 

Thanks!