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justin-branam

What's the fastest shutter speed with Rebel XT and

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Im kinda flustered. I finally got my ike housing in today and got to try it out with my ds-125. problem is, when im using the strobe, the camera sees the flash and only allows me to shoot at a max of 1/200th. With my 5050, i could use whatever shutter speed i wanted and it would almost anger me if i can only shoot a max of 1/200th using a strobe with a system costing over $2500!! Is there some way to make the camera think there is no strobe so i can shoot at say, 1/800th?

 

 

Short version:

 

Can i shoot faster than 1/200th using my strobe? if so, how?

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Hi Justin,

 

Your 5050 and some dSLRs (like the D70) have an electronic shutter, thus the unlimited sync speed. The Rebel and many other dSLRs (like the Nikon D200, D2x and all Canons) have a mechanical shutter. For a nice explanation on sync speeds check this link:

 

http://www.kenrockwell.com/tech/syncspeed.htm

 

Short answer: No, unless you use a housed Canon eTTL flash.

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Maximum shutter speed for the Rebel XT is 1/200. You can put tape over all the camera contacts except the big one and the side rails to override the sync limit, but when you get over about 1/320 part of the picture will be cut off. There will be a big dark line where the image is cut off! The shutter is not the same as the Olympus point-and-shoot. The Oly doesn't really have a shutter.

 

If you want faster shutter speeds, the Nikon D70 has 1/500 sync!

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Herb and many others here have shot at 1/300 and shown that the max you should set is 1/320th. Of course, to get these speeds, you need to use a manual strobe connection - meaning only two pins make contact - the fire and the ground. To do this, you mask off all but the center pin on the camera hotshoe.

 

Cheers

James

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Agree, I didn't suggest that (and didn't do any research on it) because I thought he was shooting on TTL (Ikelite housing + strobes).

 

Luiz

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I forgot who did the original tests. It was posted here awhile ago. The Inon Z220 will sync at 1/320 on manual. At that time the DS125 will only sync at 1/250 on manual, at 1/320 a thin black band is visible at the bottom of the photo. I think Ike has made changes in the DS125 recently so newer versions may work at 1/320.

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Masking of the image caused by the moving shutter curtain is imposed by the camera, and all strobes will mask at the same shutter speed with a given camera.

 

The issue Herb mentions w/ the ds125 was that its big round flash tube ramped up more slowly than the small square flash tube used by many other strobes, so at speeds above 1/250 you would likeley cut off some of the flash duration, causing less than the full emittance of the strobe to be recorded by the sensor. With the DS125's new IGBT circuitry, I doubt this is still relevant.

 

If Justin tapes off contacts to get somewhere between 1/2 and 1 f-stop of added control over background exposure, he gives up Ikelite's excellent E-TTL conversion circuitry.

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That's a good point Ryan. Now that I think about it more carefully, I not sure why the masking would depend on the strobe. Cristian posted the first test of the 300D way back here:

 

http://wetpixel.com/forums/index.php?showtopic=4548&hl=

 

and reported a small dark band at 1/320 with the DS125. I shoot at 1/320 all the time with Inon's with no problems.

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I shoot in M mode with my Rebel Xt and occassionally push the shutter speed to 1/250 and 1/320. See some slight darkening and / or underexposure due to mis-match of strobe synch and exceeding specified mx X, but it seems to work (???)

 

I even shoot this way with eTTL2 on and simply dial in less EV. Instead of -1.0 or -.5 I maybe leave it on ZERO compensation. eTTL2 still attempts to adjust flash output OK by my results.....

 

YMMV

 

dhaas

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Interesting David. With the xt you can set the housing to ttl and the camera will let you set a shutter speed faster than 1/200?

 

With my Rebel 300D and Ike eTTL1 housing, if housing was set to TTL and shutter speed faster than 1/200, the camera would automatically go back to 1/200. In Manual flash mode the camera would let you set faster shutter but not in TTL.

 

Does the XT's eTTL2 work differently or were you doing something tricky.

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Bill,

 

In Houston today, going home to OH in the morning....Nothing tricky, and I sure don't tape any contacts on my eTTL2 capable hot shoe :(

 

What you DO have me wondering is with the original Canon Digital Rebel and now XT if I set the shutter speed to 1/250 or 1/320 is that shutter speed what camera actually fired at with eTTL or eTTL2 (????)

 

Will need to look at EXIF data as 900 photos from Cayman Brac last week are currently on my 30GB iPod. I don't think I can read EXIF data until I import them into my home machine.....

 

Will report back tomorrow or Wednesday. All I know it looked OK on the camera screen UW. I noticed I got a slightly darker photos unless I dialed FEC back to ZERO for wide shooting where I usually use -1.0 or -.5 as previously mentioned.........

 

Will let you know what the EXIF says...

 

dhaas

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Hi Justin,

 

Your 5050 and some dSLRs (like the D70) have an electronic shutter, thus the unlimited sync speed. The Rebel and many other dSLRs (like the Nikon D200, D2x and all Canons) have a mechanical shutter. For a nice explanation on sync speeds check this link:

 

http://www.kenrockwell.com/tech/syncspeed.htm

 

Short answer: No, unless you use a housed Canon eTTL flash.

 

I just wanted to clarify the above post. Pretty much all 35mm cameras since the late 1980s have had electronic shutters (specifically, electronically timed shutters). What sets the D70 apart from other cameras is that it is designed such that the fastest actual physical shutter speed is 1/250. Then, to implement faster shutter speeds than 1/250 the camera essentially turns the sensor on and off. Thus, the shutter is open for much longer than the sensor is actually measuring. Because of this, the shutter is completely open for all "shutter speeds" and therefore you can get high speed flash sync with a regular flash (high as you want in principle, but they conservatively rate it to 1/500 because some flashes may require more than 1/1000 to fully dump).

 

As for answering the OP, no you cannot get flash sync at higher than 1/200 on the Rebel XT (or 1/250 on the D2X or 1DSII for that matter). However, I guess I would find myself wondering why you would need it? Most people desire high speed sync for either 1) very bright light conditions, or 2) fast moving subjects shot with long lenses. None of these exist underwater.

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I think Justin is trying for jet black backgrounds during daylight shooting with strobe. Correct me if I,m wrong in what you're trying to achieve, Justin...

 

 

High shutter speeds will help this plus darker sunbursts, light rays, etc.

 

dhaas

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Dave, you're in Houston? Give me a call bro - you've got my number.

 

Cheers

James

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I’ve just received my two new DS-125 strobes :(

So I’ve done a few shots with short sync speed with the Z220 and DS-125. My 10D curtain starts to show up at 1/320 already with both strobes. At 1/250 the curtainwasn't visible, no matter which of the two strobes I used (this is just a matter of the partly opened curtain, not the strobe dump speed). However, Z220 brightness seemed to be reduced a little bit stronger at 1/250 compared to 1/200 than the DS-125. This would mean the DS-125 is even faster. Both strobes have been set to full power. But I’ve done just a few quick images with some ambient light. I will have a closer look at this item.

 

@David,

 

I understand you stated that your 350D syncs shorter than 1/200 sec when the camera shows an external E-TTL strobe (Ikelite conversion unit) connected??? I would appreciate to have this confirmed. Honestly, from my understanding it sounds unrealistic as Canon DSLRs won’t allow faster speeds than specified. Only if the camera doesn’t know there is a strobe attached or you use a canon land gun with FP mode. But this is certainly not the case when the camera indicates E-TTL operating mode.

 

@Justin

 

I wouldn’t be too sad about this. In order to reduce ambient light: how much could you stop down with your Oly 5050? I guess f8 was the smallest aperture? You can go to f22 or even smaller (depends on the lens). When you shoot sunbursts you often need bright strobe light when stopping down. With 1/500 or 1/800 you cut away a lot of strobe light with common strobes @full power. Better stop down the aperture (not just f8 as before).

 

Julian

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I imagine that the 350D works just like the 10/300D. The camera is not in constant communication with strobe. After a few seconds, the camera forgets a strobe is attached. The camera will then let you set a higher shutter speed. But as soon as you "wake" the camera up by pressing the shutter button, the shutter camera remembers the strobe is attached and reverts back to 1/200.

 

The camera acts the same way when connected to a canon flash.

 

I bet that David was just setting high shutter speed but the camera was reverting back to 1/200 before taking the shot. The perceived difference in exposure must be placebo.

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Can't add anything but to say when I push 320 with my Inons I get masking at the bottom. (Ryan modified the hotshoe connector to allow higher shutter speeds). Herb, any way to explain how you are getting no masking at 320?

 

I still haven't found an appropriate replacement setting to my old 5050 to get black background when shooting kelp in the daylight, a la:

May_23_2004%20(38)Kelp.UWP.jpg

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Can't add anything but to say when I push 320 with my Inons I get masking at the bottom.  (Ryan modified the hotshoe connector to allow higher shutter speeds).  Herb, any way to explain how you are getting no masking at 320?

 

 

All I can say is that my setup has always worked at 1/320 sync. No mods needed. I think Ryan modified your setup for the S&S strobes. Almost every one of my WA shots in the Bahamas trip were taken at 1/320, and I think Todd did the same. No problems.

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I shoot in M mode with my Rebel Xt and occassionally push the shutter speed to 1/250 and 1/320. See some slight darkening and / or underexposure due to mis-match of strobe synch and exceeding specified mx X, but it seems to work (???)

 

 

 

Might be as simple as the ol Nikonos days, you could set your shutter to 125 or 250 or 500 or whatever BUT...the camera would override and the shutter would still only synch at 90. So yours might still be going off at 200, you just don't know it. But i certainly could be wrong about that.

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Might be as simple as the ol Nikonos days, you could set your shutter to 125 or 250 or 500 or whatever BUT...the camera would override and the shutter would still only synch at 90.  So yours might still be going off at 200, you just don't know it.  But i certainly could be wrong about that.

 

This is definely not the case. At 1/400 you will always have the lower ~1/3 of the pic cut off from the strobe light.

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This is definely not the case. At 1/400 you will always have the lower ~1/3 of the pic cut off from the strobe light.

 

And if you turn your rig upside down you use these speeds and have blue water (where you don't need flash at the top of the frame). I did this quite a bit with my D100.

 

Alex

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And if you turn your rig upside down you use these speeds and have blue water (where you don't need flash at the top of the frame).

 

now THAT is clever! :D

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that's cool. Should gain about one stop against sunlight with my 10D. Good hint.

 

Julian

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I still haven't found an appropriate replacement setting to my old 5050 to get  black background when shooting kelp in the daylight, a la: [very nice image snipped from quote]

 

Chris,

 

The minimum aperture on the 5050 is f/10 and max shutter speed is 1/1000. This combination is (approximately) equivalent in EV to f/22 at 1/200, which is available with flash sync on every single DSLR produced and 99% of DSLR lenses (a very few specialty lenses go only to f/16). Thus, the same exact black background is easily achieved. The only difference would be that f/22 requires a more powerful strobe burst to light the kelp. Is that the problem? If so, you could try using a wider lens and getting a little closer to the kelp.

 

[As an aside note that the 5050's sensor is roughly 1/3 the size of the average DSLR and hence f/22 on a DSLR should be sharper -- have less diffraction -- than f/10 on the 5050 so the DLSR is also better on that front. f/22 on a DSLR should be roughly equivalent in diffraction limited sharpness to f/7 on a 5050.]

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