YS90-Auto Woes!

I have a YS90-Auto strobe and to be honest I dont like the fact that it varies the light output automagically! Im wondering if anyone has ever tried to place a peice of electrical tape over the little photo sensor on the front to get the strobe to always put out the same amount of light at each f stop? Would it behave like a DX at that point??

THanks

Phil

I understand you want to block the sensor completely from any light input in order to disable the strobe’s own metering system? I am afraid this won’t work. If you block the sensor the strobe would always think there is not enough (flash) light and I am pretty sure this would result in a full dump – no matter what f-stop is dialled in.

Theoretically you could install a small bulb/light in front of the sensor and adjust the brightness in such a way that selecting the smallest f-stop would result in a full power dump. But I doubt this being a reasonable solution?

I am surprised that the ys-90 auto does not feature manual power levels.

Regards,

Julian

If you use the strobe in Auto 2 mode, you can control the light output by simply adjusting the f stop dial on the strobe ( max at f 22, least at f 2 ) In this mode it is independent of the f stop you use for your camera setting and there is no quenching. So in effect you have a manual strobe with a 12 level variable output. I use it in this way all the time.

I do use the strobe in mode2 and it unfortunatly does vary the output of the strobe according to what the strobe thinks you need. The diferent modes are for the different types of flash from the camera i.e. pre flash or no preflash.

I guess Im going to just have to get the DX, or get a new camera that has a sync cord and does ttl and is compatible with the sea&sea strobe....

thanks

Phil

Phil,

so I understand "mode 2" does permit pure manual settings only in conjunction with a sync cord connection? And Auto strobe function when driven by optical signal?

Regards,

Julian

The only difference between Auto 1 and Auto 2 is when the flash sync's. Auto 1 is for non-preflash systems and will fire on the first sync signal. Auto 2 is for pre-flash systems and will fire on the second synch signal. This works for corded or slaved connections.

When I first read this thread I assumed that blocking the Auto Sensor (top sensor near Sea & Sea logo) the strobe would fire at the maximum output so I did not reply. Then I got thinking about it and felt that the different aperture settings were in fact simply sensitivity levels and would adjust the output level even if the sensor was blocked. So I did some tests and fully blocking the the auto sensor does in fact make the strobe operate similar to the YS-90 DX. A minimum output is given at the 2.0 setting and a maximum output is delivered at the 22 setting.

Thanks for the Info, I really did not expect this, because when there is no light going onto the sensor, the exposure still should be to dark for the strobe's metering system (like the traditional TTL system test, block the lens and you get a full load). Strange for my logic The dial seems to have an overall limiter function too?! But good for Phil if it works reliable.

Regards,

Julian

Well now Im gonna have to spend hours above and below the water trying to figure it out!

Thanks for testing it for me.. Actually what I should do is break out my flash meter and test it that way.. I had totally forgotten that I had it!

Ill let you guys know how it works..

Hmm I have a friend who has a dx, maybe Ill borrow it and compare the results!

thanks again

Phil

Actually what I should do is break out my flash meter and test it that way.. I had totally forgotten that I had it! Hmm I have a friend who has a dx, maybe Ill borrow it and compare the results!

<{POST_SNAPBACK}>

The flash meter would be a great test, I look forward to your results, especially comparing with the YS-90 DX. The biggest problem will be in trying to fully mask off the sensor as it' sits behind the flash lens. I expect that there will still be some slight variation in the output level even when masked as best as possible.

The dial seems to have an overall limiter function too?!

<{POST_SNAPBACK}>

This is correct, the aperture setting dial is in fact a power level limiter that works in conjuction with the auto thyristor sensor circuit to control the flash output based on the distance to the subject and the aperture of the lens. It's also important to note that this sytem assumes an ISO setting of 100.

My previous post didn't say that I use the YS 90 Auto in a corded way. I assumed that was the case. In fact I currently use it with my 20D in a Subal C20 housing with a Sea & Sea N5 sync cord.

I just ran a few tests again. In Mode 2 it really does work for me as a manual strobe with selectable output. I watched the histogram sequentially creep over from the left to the right side as I advanced the f stop setting on the strobe from f 2 to f22. This works for any camera f stop. There is no quenching as it will overexpose when flash output is over selected.

So for me there is no need to tape the sensor

so maybe this "auto strobe with blocked sensor" is a manual strobe in this certain mode, that would sound more logical to me now and would explain the behaviour But I don't know this strobe and its operating manual, you guys should work it out

Regards,

Julian

The Auto 2 Setting will only work with pre-flash systems, corded or slaved. The output level is certainly adjusted based on the aperture level setting but if the sensor is not blocked it's also adjusted based on the distance to the subject.

If I recall from other posts, Phil is using a DX-5000 which is not a pre-flash system so he must be set to the Auto 1 position.

I had two YS90 Autos on a Subal/D100 and had a lot of unreliable exposures with trying to use them in forced manual (even with the sensor covered auto1/2).

I never found a reliable answer so changed to Inon.

I have also seen people having problems with these guns. Far too much chat going on between camera and strobe for my liking.

Alex