S&S 350D housing and TTL Converter

...about 6 ft from subject.

I was suprised it darkened so much at f32.

Why?

Hi,

I got a Sea& Sea TTL converter and make a quick with a Z-240 strobe.

The housing is a Sea&Sea DX-5D, camera Canon 5D, EF 100mm f2.8 macro USM.

The flash was without EV filter, flash setting like Pakman.

The camera setting was: iso 400, 1/200s, aperure 2.8 3.2 4 5.6 8 11 16 20 32.

Converter: 0EV and +1EV.

I made a comparison with a Canon strobe 580EX.

Generally, I found the results of the converter/Z-240 not so far from the 580EX.

Except at f4, where I can say: I don't know what's appened. I made 3 time all the pictures to be sure of the results.

Next time, I will change the subject and make a new test, to check what's append at f4.

Just a comment about darker images at smaller apertures. It may be that at f32 you are requiring nearly a full dump from your strobes for the appropriate exposure. If you are shooting several shots in a row, such as a series, it is very likely that your strobes are not fully recycled when you take the later shots. Although the strobe indicates the ready light it does not necessarily mean it is able to output a full dump, or even near that. Be sure to give plenty of time between shots for the strobes to fully recharge if you are gauging exposures like this; otherwise, you may get misleading results. Even if it means the beer gets warm!

This was a lesson learned for me over many series of strobe exposure tests...

And a comment about the heinrichs converter - I just used one on a recent trip, with Z240 strobes and a D2X. As with ANY camera, I do exposure tests ahead of time and dial in the compensation that I need for a particular camera, for both normal metering and TTL metering. I determined what compensation I wanted for the combination of the D2X, Z240 and heinrichs converter, and was very happy with the consistency of results over the course of the trip. TTL doesn't mean I never use manual, but it is another tool, and I'm happy to have it.

A friend who was on my trip had a 5D in an Ike housing with Ike's eTTL (using DS125 strobes). We might have been able to compare results if her setup had been working. Unfortunately, it was malfunctioning, and in spite of all attempts to troubleshoot and fix the issue, all her exposures on the trip were 2-3 stops too dark... Apparently was a faulty cord, and strobes wouldn't fire at all in manual. I think she would gladly have taken "within a stop" over "not working".

Hi,

I got a Sea&Sea TTL converter whish I have install on S&S DX-5D housing and attached one Z-240 strobe.

I made a comparison with a Canon strobe 580EX.

The camera setting was iso 400, 1/200s, f2.8 to f32.

Flash setting like as Pakman.

Converter 0EV and +1EV.

I made 3 times the test.

I found the Z-240 result close to the 580EX except at f4 where I can say: I don't know what's appened.

So, I think also than the results are similar to the Pakman results.

Next step is to change the shot condition to check what's appened at f4 and make a comparison with a YS-110 strobe when he will be available.

f2.8

f3.2

PS: the pictures are in several posts.

Claude - you're attachment has three pics labeled f2.8. Are all three photos at f2.8 or different aperture settings? Did you mean to attach more pictures?

Linda- good point about full dump/ f32. If I have time, I'll go in reverse order and start with f/32 and take plenty of time between the shots.. edit: Linda- love the pics on your website especially the mating mandarin fish!

f4

f5.6

f8

Hi Pakman,

Yes the 3 pictures have the same aperure:

1st: Z-240 + converter at +0EV

2nd: 580EX

3rd: Z-240 + converter at +1EV

f11

f16

f20

f32

Oh thanks Claude. Looks pretty good although that is strange about the f4 set. Thanks for also including the 580EX speedlite comparisons. I was too lazy to do that with my 430EX flash...

claude, thanks again for the info and testing.

one things that just came to mind that might explain some of the differences is the following:

i am assuming you positioned the 580ex on the camera' hotshoe, however, how did you position the z240 when you ran the test? was it on the top of the housing or on the side?

just wondering if that could that affect the exposure metering for the ettl?

/paul

edit: just looked at the photo of your housing setup guess my comment doesn't really apply as it seems the z240 is on top of housing as well...

Hi Paul and Pakman

eh Paul, you are everywhere.

Yes, the 580EX was on the camera hotshoe, the camera was on the same place than the housing.

The Z-240 was on the top of the housing, like this picture:

But, I removed the strobe filter to took the pictures.

It's a good idea to check what's the influence of the stobe postion.

Hi Claude,

Why are you performing your tests at ISO 400? Do you shoot macro at ISO 400?

I think you should do the test at ISO 100 with the subject about 18" from the tip of the lens - like a real shooting situation.

These sure are some "wonky" test setups we are seeing here - it would help simplify things if folks would follow some basic guidelines - with the mantra "try to simulate real macro shooting."

ISO 100

Macro lens

Subject at 18" from lens tip

Manual Camera Mode

Shutterspeed BELOW the max sync speed (1/180th)

Single strobe first, then dual strobe test second

Thanks

James

Gentlemen,

James is right in that a set of parameters like real world shooting would make testing and evaluation of and TTL system accuracy much more valid.

Like lowest ISO and NOT 6' away and then wondering why f32 results in a dark photo! Let's see, the Canon 20D crop factor of 1.6 makes the 60mm equal angle view to about 96mm, and f32 is like a pinhole....SOOOO, how much strobe power do you think it's going to require to light something in that situation (answer - A LOT!!!)

James' parameters are spot on for macro range shooting.

YMMV

dhaas

OK, OK, OK... got some time to kill before the Australia/ Italy match tonite...

Same setup as before, 350D, 60mm, about 12" away, ISO 100, 1/100, TTL Converter on and set to EV 0, but with only a single Z-240 strobe positioned just above the camera. No diffuser... pretty much the same results as before. f/2.8 overexposed (maybe the TTL converter can't squelch the strobe fast enough??).

OK, I'm off to the local pub... cheers...

Thanks Pakman!

For the range of apertures that most people shoot macro (not f2.8 obviously) those are very good results!

Cheers

James

If the test is being done in air shouldn't it be done at 3x normal shooting distance of macro underwater to account for difference in light absorption ?

Ha ha, Theese tests can go on forever with different settings... I for one have become more confident that the Heinrich converter will work just fine for the type of macro work that I do.

One thing that came into my mind hovewer: Does the converter know If you are using one or two strobes?

aah, can't believe Australia lost to Italy in the last seconds to a penalty shot!!!! Oh they were robbed!!

Vannar, I was thinking the same but I did have some test shots tonite with the 2nd strobe on and the they came out pretty close.

Hi Matt,

I am not sure what the air guide number is for a DS125, but I had guessed around 60. With two strobes that should have given me a decent exposure at f22. Guess I was either optimistic, or didn't let it fully cycle as was suggested.

SB

Why? 

 

~Matt Segal

<{POST_SNAPBACK}>

I am not sure what the air guide number is for a DS125, but I had guessed around 60. With two strobes that should have given me a decent exposure at f22.

Many issues here. First is the guessing - I'll let that be . Second - were the diffusers on (lower power reaching subject)? Third - adding guide numbers is not as simple as GN#1 + GN#2. The formula is NewGN=SQRT(GN#1^2+GN#2^2+...). Even if the air GN of the DS-125 was 60 (ft), the GN of both of the strobes would be ~85 (ft), and at 6ft and f/22, would not provide a correct exposure.

Hope this helps