Oly 770SW vs Canon 570IS

[Nemrod]

Thank you for the link. I am sorry I am not describing things well. If you read the link you will see mention of the magnet. I am shooting the Canon in both strobe External Auto and Manual with the camera set in manual or Av mode.

I am shooting the Oly in the S-TTL mode, optical synchro, no magnet installed.

I am shooting the Canon in manual and AV with the strobe in External Auto or Manual but as I said, without installing the magnet, when I switch from camera auto mode to manual or Av the strobe looses sync. It regains sync by installing the magnet and using External Auto or Manual. Yes, there is much to figure out still to get optimal settings. I find it somewhat strange you guys have not encountered this. I do not think the camera is using a preflash in Av or Manual with internal flash armed or in auto (camera flash to auto mode). It is complicated, that is why in another thread I asked if anybody shooting a similar rig had some "pet" settings. Since nobody seemed to I am working mine out on my own. I will experiment more soon to determine if I am wrong on this preflash thing and some other aspect is interveneing.

Thanks again for any and all info.

N

 

[ce4jesus]

I've never worked with a canon before so the configuration or menu settings would be foreign to me. However, I'm pretty sure on the preflash. In my old Oly SP-350 I had to place the internal flash to slave mode, then choose an output from 1-10 in order to disable the preflash. In most P&S cameras you can't do that so they always, even in manual mode, have an invisible preflash sent by the camera. Some strobes are set to ignore this, and others are set to mimic the preflash. I'm just a little confused why the canon doesn't work in S-ttl mode with the Inon. Anyway, I went through this little exercise when I upgraded to an E410. The YS27DX strobe I had failed to work with the DLSR's preflash. Worked fine with the Oly SP-350. So after numerous experiments and calls, chats etc it boiled down to the YS27 not being capable of ignoring the E410's preflash signal so it was always out of sync...except when the internal strobe was set to manual and an output chosen for it.

 

[Nemrod]

I believe the Canon will work in S-TTL, but to do so I have to remove the little magnet. To shoot in Manual or Av/Tv I had to install it. Removing and instaling it underwater is a NO GO. Therefore I never really shot the Canon much in Auto with the strobe to S-TTL. To bad the Inon does not have a simple switch for that mode change. In any case, both the strobe and cameras workgreat but as I said, the extra fuss of theCanon and it's multiple modes makes it more complicated and for the most part the Oly took just as good a pic without all of the fuss. The next trip I will do more to investigate for sure and compare both directly. N

 

[Nemrod]

Here is one of the things I have figured out JFYI. When the 570IS internal flash is selected to auto it will fire a preflash. When the 570IS internal flash is set to manual it does NOT fire a preflash. What this means is that for external strobe users that do not have a direct switch but instead have to install the "magetic" cancel (Inon D2000 and others) you MUST then decide during predive setup which mode you will be shooting in, auto internal flash or manual internal flash.

This link has some interesting blabber.

Mark's Favourite

N

 

[alcina]

Oh, that's easy then. Forced flash (manual) is the way to go. I even set that on my Oly SW720. Set it up before I hit the water and don't think about it again. If I don't want flash for whatever reason I switch it to off then turn it back on again.

 

[ce4jesus]

Here is one of the things I have figured out JFYI. When the 570IS internal flash is selected to auto it will fire a preflash. When the 570IS internal flash is set to manual it does NOT fire a preflash. What this means is that for external strobe users that do not have a direct switch but instead have to install the "magetic" cancel (Inon D2000 and others) you MUST then decide during predive setup which mode you will be shooting in, auto internal flash or manual internal flash

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yes this is true; however, but changing the camera from A mode to auto mode or to manual mode should have no affect on the mode of the flash, unless when you put the camera in manual mode, the flash is also set to manual mode. But this too should be something you could change before the dive. Therefore, you should be able to dive with the camera in manual mode, the flash in auto or forced, and the Inon's in s-ttl.

 

[Nemrod]

.

yes this is true; however, but changing the camera from A mode to auto mode or to manual mode should have no affect on the mode of the flash, unless when you put the camera in manual mode, the flash is also set to manual mode. But this too should be something you could change before the dive. Therefore, you should be able to dive with the camera in manual mode, the flash in auto or forced, and the Inon's in s-ttl.

No, I don't think so.

In Av or Tv you can set the internal flash to 1/3, 2/3 or full, essentially manual control. In this mode the internal does not emit a preflash, that is what I think to be true. In this condition you cannot use the S-TTL which only works when the camera's flash is in auto and is emitting a preflash as it would with the camera set in auto, no choice, the flash will set to auto. THUS--you cannot switch from the D2000 set for preflash for the camera in Av/Tv with manual internal flash to Av/Tv with internal flash on auto in the same dive --because---you would have to remove the magnet switch in the D2000.

I think if you leave the camera's flash in auto then it will emit a preflah in Av and Tv and therefore will allow the Inon D2000 to operate in S-TTL mode with the magnet removed.

I have observed that with the camera in auto, internal flash will be in auto and set the D-2000 to S-TTL and with the Clear Photo film on the strobe then I do notice that the D-2000 is able to overide the camera's internal flash and trick it into firing at lower power--by emitting a much stronger preflash. This strong preflash fools the camera into thinking it hardly needs any flash at all.

Well, I can see you guys are as confused as me.

Maybe someday if I ever figure all this out I will make an Excel spread sheet showing camera exposure modes, preflash condition, internal flash mode and corresponding Inon settings. Don't hold your breath however. It may be a while. I was kinda hoping someone had already made one.

N

 

[ce4jesus]

In Av or Tv you can set the internal flash to 1/3, 2/3 or full, essentially manual control. In this mode the internal does not emit a preflash, that is what I think to be true. In this condition you cannot use the S-TTL which only works when the camera's flash is in auto and is emitting a preflash as it would with the camera set in auto, no choice, the flash will set to auto. THUS--you cannot switch from the D2000 set for preflash for the camera in Av/Tv with manual internal flash to Av/Tv with internal flash on auto in the same dive --because---you would have to remove the magnet switch in the D2000.

Again I've never worked with Canon but its very odd of them to fix the flash in manual mode when you flip the camera into aperture or manual mode. Since this appears to be the case, I can understand the frustration.

Maybe someday if I ever figure all this out I will make an Excel spread sheet showing camera exposure modes, preflash condition, internal flash mode and corresponding Inon settings. Don't hold your breath however. It may be a while. I was kinda hoping someone had already made one.

aw c'mon....be great reading during a sleepless night..haha.

 

[Nemrod]

Again I've never worked with Canon but its very odd of them to fix the flash in manual mode when you flip the camera into aperture or manual mode. Since this appears to be the case, I can understand the frustration.


aw c'mon....be great reading during a sleepless night..haha.

They don't fix the internal flash in manual, it is defualt in auto. This is a setting many use to reduce the internal flash power consumption to reduce heat, potential fogging, battery drain etc. my point is that you cannot switch back and forth, you must choose before the dive by setting the Inon D2000 to one mode or the other (magnet in or out).

I know it is complicated, that is why I started this thread hoping somebody had already figured it all out, lol, I guess not.

Yeah, a spreadsheet, cold night, hot chocolate, sounds warm and fuzzy.

Another thing, when I shoot strobe with my Nikon FMII full manual film slr (or my Nikonos III) I would set the apeture, shutter would be set to 1/250 sync speed and then I would use auto on the flash and set the camera arpeture on the strobe dial. HOW--does the Inon work auto with camera in Av (with internal strobe set to manual 1/3) where you set the arpeture on the 570IS and then match to the knob on the Inon D2000 when you cannot preselect the shutter. The only way I see to do this is to use full manual on the 570IS and select both shutter and f stop.

I. Canon camera modes available:

Auto--flash auto or off--always a preflash
Av--flash off or forced (preflash in flash auto only--select in menu auoto or manual)
Tv--flash off or forced (preflash in flash auto only--select in menu auto or manual)
P--flash auto or off or forced, always a preflash (I think there is a prflash)
Manual-- forced (on) or off, never a preflash.



Inon D2000 modes:

S-TTL--works with camera flash with camera exposure set to auto, possibly Av and Tv and P as long as the internal flash is in auto so it produces a preflash

External Auto--works with Av, Tv, Manual, cameras internal flash set to manual (1/3, 2/3, full)

Manual--works best with camera in manual so you can set shutter and apeture to known valvues

Full--fires at max power--probably camera in manual only or with internal flash set to manual in other modes.

Note: The Inon D2000 MUST be selected to preflash mode or no preflash mode by installing a magnet in a small hole BEFORE the dive. This cannot reasonably be done underwater. So you must choose before hand.

Note: Flash cancel circuitry, ?????? still figuringthat out, seems to workin external auto but still figuring out camera setting to match
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Some of the stuff above is possibly wrong or incorrect or speculative. This is the sort of info I am trying to figure out. I think it would be helpful to many. If you know as FACT and have actually verified it by operation as FACT please feel free to alter my statement.


II. The Oly 770SW camera modes:

Flash, forced, auto, off, (always in auto exposure mode, always a preflash)


Inon D2000 modes:

S-TTL

External auto, magent removed


N

 

[Nemrod]

In the old simple days an auto flash would be used by setting arpeture on camera and matching to The strobe. the shutter speed on the camera was assumed to be a sync speed of 1/60, 1/125, 1/250. This was then accounted for by various other manipulations and then forgotten during shooting as being irrelevent. Shutter sync speed was NOT a variable (except for B). So, with a digital camera with no shutter sync speed how does the modern auto strobe know what shutter speed is? Yeah, you match arpeture but how do you know the shutter speed unless you go to manual camera exposure.

This makes my brain hurt.

One other thing, comments?, I think that the Inon Clear Photo System does work. You are supposed to cover the flash with the provided IR passive film to block visible light thus reducing backscatter--however--at least with the Oly 770SW and teh Canon 570IS the large Inon AD lens adapter includes a LARGE flash blocker/optical sync adapter. This seems to effectively eliminate or reduce backscatter form the camera internal flash. I have found that removing the IR film seems to have no effect on operation of the Inon D2000 or backscatter. Any thoughts. Why remove it ?, well, to eliminate any possiblity of overheating the camera strobe and damaging it, just extra stuff to complicate, no other reason.


N