S90 AV/TV Defaults

[floridafish]

Am I correct that when set to AV, the shutter speed defaults to 1/60 and doesn't change even when the F-stop is changed?

When set to TV, the F-stop defaults to 2.0 at wide, to 4.9 tele?

I just don't get it--I thought by definition, in AV the camera selected the shutter speed--not just defaulted to a shutter speed.

Ditto for TV mode--I thought the camera selected, not defaulted, to an F-stop.

Is there some additional setting that I am missing?

Thanks,
FF

 

[skynscuba]

Read pages 95-97 of your S90 manual, http://gdlp01.c-wss.com/gds/7/0300002637/04/PSS90_CUG_EN_04.pdf

 

[floridafish]

Unfortunately, I have read, and re-read those pages. Which is why I am asking the questions, as the camera does not seem to be acting as described in the manual.

FF

 

[jd950]

On the Canon G10 and G9, if you have flash set to on and are using an external strobe, the camera will default to 1/60th in A mode and will only choose a higher shutter speed if it cannot reduce the flash output enough to avoid overexposure. Most often, it is hard to get the camera off of it's favorite 1/60th speed in A mode.

Similarly, if in T mode, it will lock onto the widest aperture until it has no choice but to stop down to avoid overexposure.

If I am recalling correctly these cameras also have a preference for large apertures in the P mode, but I think you might be able to switch that. I can't recall.

To avoid these issues you can shoot in manual, but there is no TTL available in manual.

I thought Canon had changed this in the S90 and G11. Perhaps not.

 

[Nemrod]

Unfortunately, I have read, and re-read those pages. Which is why I am asking the questions, as the camera does not seem to be acting as described in the manual.

FF

Well, read it again because it is clear. When in Av mode you select the f stop and the camera selects the shutter speed and when the flash is selected ON the maximum shutter speed available the camera can select for strobe sync is 1/500th second.

If you are shooting in Tv mode you select shutter speed available is 1/500th second and the camera sets the matching f stop.

Using the +/- function on the ring control you can bias the exposure up to two full stops in either direction.

Example in Av mode, +/- set at 0, you select f4.0 and the camera determines that the proper exposure is 1/125 second.

Example in Av mode, +/- set at -2.0, you select f4.0 and the camera will determine for the same scene as above--same conditions--the shutter will be 1/500.

Example in Av mode, +/- set at +2.0, you select f4.0 and the camera will determine for for the same scene as above--same conditions--the shutter will be 1/60th second (apparently regulates with flash and will not go below 1/60th).

If you arm the flash to ON the maximum shutter speed in all cases, Av or Tv will be 1/500th second.

Shoot with Safety Shift OFF.

In Av mode you can select 1/1000 second but if you select flash to ON and do a half press you will see that the S90 defaults to a max 1/500th second. Then when you go back to flash OFF then do a half press you will see that the 1/1000 is now available. You will see this activity only when you do the half press.

Tv mode works similar except you are selecting the shutter speed and when you select flash On then 1/500 is the max speed.

N

 

[jd950]

I don't think re-reading the manual will help if floridafish is frustrated by how often the camera shoots at 1/60 on Av or at full aperture on Tv. I haven't used the S90, but I have now looked at the manual and it does seem the S90 is the same as those the G10 in this regard.

I assume he/she is using an external strobe. On Av, the camera will only move higher than 1/60th if it cannot obtain a correct exposure by regulating the flash output. During the day in shallow water it will likely have to use a faster speed due to the amount of ambient light, but deeper or at night, it may never move off of 1/60.

On Tv, it will stop down only if it cannot reduce flash output sufficiently to obtain proper exposure and again on deep or night dives, it is likely to stay at or near wide open.

Safety shift is inoperable with the flash set to on, so that doesn't affect this.

Luckily, although 1/60 may not be fast enough to avoid blur on some subjects, if the only significant light is from the strobe it will still likely avoid blur, and if you have sufficient ambient light, the camera will probably need to rasie the shutter speed.

Unless I am on manual, when concerned about shooting moving fish with the G10, I use Tv and set the shutter speed to the speed I need and live with the aperture the camera gives me. On the other hand, if my subject is static, I am likely to go to Av and select the aperture that I think best and I know that the camera is likely to be at 1/60.

One can also play with strobe output or operation.

Of course, maybe this isn't what floridafish was asking about at all.

 

[floridafish]

Thanks jd950 you addressed my question and frustration. I want to shoot sTTL (S2000), but now I am faced with the problem of 1/60 shutter speed (AV) and in TV mode with limited f-Stops. Your suggestion of switching back and forth between AV and TV looks like the only solution (opther than shooting Manual).

Thanks
FF

 

[Nemrod]

I don't think re-reading the manual will help if floridafish is frustrated by how often the camera shoots at 1/60 on Av or at full aperture on Tv. I haven't used the S90, but I have now looked at the manual and it does seem the S90 is the same as those the G10 in this regard.
.

I answered his question but requested he/she re-read the pertinent pages you listed.

I actually have the camera and actually answered the question but since he/she did not bother to read what I took my time to actually sit down in front of the computer with the camera and with Inon strobes rigged and set for sTTL and then record actual camera settings in multiple examples well, I give up.

I guess I should correct one thing, despite having the camera set on my couch with plastic fish, I guess I did put down one thing incorrect, I must have switched to manual as I worked between flash settings and modes when I was able to get a 1/30th, this does not seem to happen except in Manual mode.

In any case, good luck to all.

N

 

[jd950]

Sorry, just trying to be helpful; didn't mean to step on any toes.

 

[Nemrod]

Sorry, just trying to be helpful; didn't mean to step on any toes.

No need to say sorry, no issues with me. You are correct and I think I was a little wrong as I sit here playing with the camera some more now, I had three glasses of wine in me when I was playing around last night, lol. Not sure what I was doing in fact.

I had been trying to set up some test shots to correct problems I ran into in Flariduh last week when this thread came up. I think I confused myself swapping modes.

I have always shot either manual or Av with strobe in manual or EA and the more I play around with Program and sTTL the less I like those modes. I am glad now that I have the External Auto.

One thing, in P mode, you can set both overall exposure compensation, +/- with the ring control (in this instance it would control background) and you can bias flash exposure under Func Set +/- (in this instance this would be your foreground subject exposure). I am finding it easier to set my D2000 strobes when in sTTL to the "B" setting and then setting the flash exposure using the Func Set flash exposure compensation setting. This would work the same way with an S2000.

N