Shutter speed and TTL

Hi,

First time I used the Nikon D300 underwater in TTL mode and aperture priority. In this mode the shutter speed is always at 1/60s.

Maybe it's a stupid question but if I want to have a faster shutters, do I have to revert to manual mode? Keeping the TTL can I increase the speed?

Yesterday the camera settings were: Aperture priority, front-curtain sync

The Z-240 inon strobes settings were: sTTL, the magnet button pushed in and the S&S TTL controller on "0" (zero)

The result was quite bad, photos with no contrast. Do you see any gross mistake in the above settings?

Thanks a lot for any help.

alex

It might be easier if you post a photo but I've heard of folks who shoot in A mode that are able to adjust the exposure down two stops...ie tell the camera you want an underexposed photo and it increases the shutter speed accordingly. Personally, I'd shoot in manual mode and do all the thinking for the camera.

I think the when the flash is used in Av mode on a Nikon, the shutterspeed defaults to a slowest of 1/60th. If you want it to go slower, you have to use slow-rear sync flash mode. If you want the shutter speed to go faster, you need more light :-) Or you need to set some exposure +/-

Cheers

James

This is one of those "perhaps I remember but I don't have my camera in front of me..." moments, but I seem to recall a setting buried deep in the Nikon menu that lets you change this default up to the max. synch speed.

I've never used it as I use Manual control with strobes, and let the strobes do the work (I sometimes use optical TTL). I shoot filters in Shutter priority, mostly.

Tim

B)

From my reading and experience with a D80 I think this is the way it's supposed to work. There's a setting where you can set it to allow a longer shutter speed but not a faster shutter speed.

The setting in question is the slowest speed allowed when using flash. In aperture mode the camera attempts to use the ambient light and sets the shutter speed accordingly, more light and you would get a faster shutter speed up to the maximum sync speed. as it gets darker the shutter speed gets slower until you hit the limit set which can be from 1/60 to 30s. I think this is a bit of shame as I'd like to be able to set the minimum all the way up to the sync speed but it's not the way Nikon see it.

I think the best option is to use manual, you know the aperture you want to use and you are after a flash only exposure so you can set the shutter speed to create a background that's as dark, or light, as you want. If you want to use A mode than set a smaller aperture, you'll still get 1/60 the flash output will be higher and the smaller aperture will darken the background.

Hi All,

If you use A-mode then you have a few possibilities for a slower shutterspeed:

1: Change the slowest allowed shutter speed, standard 1/60. I can't remember what it is called, but it is possible.

2: Use the Slow Synch Mode

3: Adjust the EV, until the slowest allowed Shutter speed is reached.

If you want to increase the Shutter Speed without changing the Aperture. Then the only chance in A-mode is to change the EV, Exposure Value. I think that you can change it +/-2EV.

Just a question, which Aperture & ISO did you set?

Hi all,

Sorry for the late reply, but I've been away. After I posted the message I found that the strobes position was absolutely wrong and together with 1/2meter viz on a dive it gave me bad photos. At that time my concern was to check for housing leakage more than having nice photos and the diving condition quite bad anyway.

At that time I used the camera on 200 ISO, A priority variable between f11-16 and shutter speed always at 1/60.

Well, I've been away and I used M-mode instead. No problems. I still have a lot of concerns about TTL though... but this is probably beyond this thread... and definitely a frustration. I think I'll go back to my old good everything-manual-mode.

Cheers,

alex

Ok, while we are sort of talking about this, what are the differences between Exposure Compensation and Flash Compensation? I am asking with respect to which has more influence setting the flash level. I'm thinking the camera can figure out a proper exposure by itself and what one really needs is some additional control over the flash level since apparently, TTL may not always produce the desired level.

Anyone care to comment?

Thanks,

It depends on the mode. In PS or A exposure compensation will affect the shutter and aperture settings for the ambient light. In M it does nothing other than effect the meter display.

Flash compensation works in all modes and reduces or increases the amount of flash exposure calculated by the camera's metering system.

exposure compensation = affects ambient light, like the background

flash exposure compensation = affects flash output, like the foreground that is illuminated by the strobes

a quick way to remember is "FEC" has the "F" which stands for foreground

good luck with your experiments!

Hi Alex,

I'm curious about your TTL concerns. I just got my self one of those S&S TTL adapters, but i have not used it yet. What exactly does not work as you expected?

Cheers

/Tobbe

Alex,

I am using a D80 & 2*INON Z240. Your system should be pretty much the same strobe wise. ( I am however envious of your D300). I am using a Heinrichs Converter mounted in the Housing. I do believe that Sea&Sea has taken it as OEM and housed it, but I am not 100% sure.

I find that the TTL works pretty good up to approx. 1m, center weighted.

I am using TTL for Macro and Manual TTL on Wideangle. I believe that INON calls it Manual TTL . On Wideangle shots the TTL tends to go full out, which gives you problems. In this Manual TTL you set the max allowed Strobe Output. This then basically sets it into Manual for Wideangle. I know that there will be a lot of people shaking there heads at this, but as the Ferrari's wrote in their latest book "TTL works for me". This is atleast for me a nice feature, since I have the Converter in the Housing. I was frequently forgetting to change the dip-switch in the Housing and this was my solution.

The Settings are ( if I remember them correct):

* The Film(Magnet) switch in the low right corner pushed in

* Main: Set it to M ( if Full, then it is the same as STTL, if M0.5-6 then you can start to turn the right wheel).

/Erik

Alex,

The Camera would lik to set a slower Shutter Speed, but this 1/60s is the max allowed time. You can change it in one of the menues somewhere. So, the chosen Shutter Speed ( by the Camera) is a function of Aperture, ISO and available light. If you lower the Aperture you should also get a faster Shutter Speed. It should also help if you go to "brighter" waters.

/Erik

When you are shooting TTL, and it starts overexposing and thus you want to go manual, do you have to change the menu setting to turn OFF TTL in the flash menu on the D300? Or does changing the dial on the strobe do all you need to do to be manual?

You shouldn't be getting overexposure when shooting iTTL. Are you using the DS125? Do you have the housing set to the right type of strobe? What lens? What is the f/stop?

If you are using the Ikelite D300 housing, you can just turn the flash compensation dial to manual and you can dial in from Full power to 3 stops under full. Leave the strobe on TTL (assuming it is an Ikelite DS strobe. Alternatively, you can just set the strobe to manual and vary the output on it.

Alex

I'm no expert, but I find your point very interesting and will explain you how I think it's working:

I use a D200 with a SB800 Strobe.

*) In the custom settings menu of the D200, I set "Flash Sync speed"

- at 1/250 (than the camera won't allow you to go faster than 1/250), but it will allow you to go faster than 1/60 up to 1/250.

pm. You have also 1/250 FP (for Focal Plane, a technique for better synchronisation of the flash with the movement of the shutter curtains), if this is supported by your flash than the flash will synchronise with faster shutter speeds than the flash synchronisation speed. I do not chose this option, as I don't see -yet:) - the advantages for UW photography, and it avoids me choosing to fast speeds when UW.

**) You have another menu to set the "Slowest speed when using flash". I set this one at 1/60

I set the flash on TTL.

Now:

In P and A mode, the camera will set the shutter speed, between 1/60 and 1/250 (depending on the ambient light). As underwater we generally don't have so much light, always 1/60

In S mode, you can set any shutter speed up to 1/250. The camera set's the apparture according to ambient light (for macro a bad UW choice; as lens to open for DOF).

In M mode, you can nicely choose your shutter speed (up to 1/250) and arrange the aparture, in function of the ambient light you want, TTL takes care of the lightning of the foreground. So I thinks this is the way to go.

I've used myself so far always 1/60 but I notice that for some species this gives a blurred effect. I wonder if they might see the pre-flash TTL burst, start moving, and ... unsharp picture. I'm going to experiment with the shutter speeds

rgds

Sven.

You shouldn't be getting overexposure when shooting iTTL. Are you using the DS125? Do you have the housing set to the right type of strobe? What lens? What is the f/stop?

 

If you are using the Ikelite D300 housing, you can just turn the flash compensation dial to manual and you can dial in from Full power to 3 stops under full. Leave the strobe on TTL (assuming it is an Ikelite DS strobe. Alternatively, you can just set the strobe to manual and vary the output on it.

Yes, flash is DS-125 and properly selected. Some blinkies using f/8, shutter speed 1/60, Tokina 11-17 FE, shooting at 11.5 or so. Shooting in manual mode. MAYBE, knowing next to nothing about photography, I should be in Program mode? Until I am comfortable with all the bleeping buttons... but maybe I'll just fiddle with exposure compensation or shutter/aperture controls to see if I can fix it underwater.

iTTL will work fine with the camera in manual mode. When shooting with strobes I never use anything other than manual mode. I occasionally have an overexposure situation on some shots when using a "smaller" f/stop ("larger" aperture) when the strobes are close to the subject. It appears that the strobe(s) can't quench quickly enough.

Depending on the depth you are at, f/8 and 1/60s maybe overexposing due to available light. Do you remember what the exposure display in the viewfinder was showing?

My recommendation would be to start with shutter speed a bit faster than 1/60s (e.g. 1/125s or 1/250s) and then go with a slower shutter if you get your backgrounds too dark. Also, depending on how close the subject is, you should be able to go with a smaller aperture.

This shot was taken at 1/60 and f/11 with a Tokina 12-24mm at a depth of 15m.

Available light would have dictated 1/60s and f/8 which I know because this was the dive when my dual sync cord started to fail and the strobes did not work at all for most of my shots. The image is nowhere near as good as I would have liked, but given the sync cord problems I was having, I was not able to do much trial and error to improve the situation.

Thanks. No, I do not know what the exposure was showing in the viewfinder. These were the first shots I'd taken in manual mode, didn't really even think to look at the exposure meter. Is it possible the "blinkies" came from the fact that the fish were silvery and just reflected the light that way? It showed up the most with the yellow snapper on whitish portion of the bodies. In any case, I will shoot a little faster on the flash.

I was only in 10 feet of water, but there was no direct sunlight as there is a tent over the tank. Was definitely very close to the subject and probably could have put the flash further out to the side. I was just so relieved my housing wasn't filling up with water and that my shots were showing up in the review panel (first time I set the camera up to show what has been shot without pressing the play button). Also the first time I had the "highlights" flashing. A lot of first for my first time underwater with the camera. I read a lot beforehand but that didn't really prepare me as well as experience will.

In the future I am going to zoom out to 17mm as well. On the wide end of the fisheye, things were crazy small unless they were mugging for the camera by looking at their reflection in the dome.

I assume by "blinkies" you mean blown highlights as indicated in the LCD.

The first thing you have to remember with TTL is it only averaging the scene (or at least part of it). This means that if you have someone white or silver on a dark background (or no background if it is a fish in open water), there's a very good chance that highlights will get blown. That's par for the course.

The second thing to remember is that TTL is there to help you but you need to understand its limitations and then work with or around them. If you see blown highlights indicated in the LCD, you need to decide what you want to do about them. If the main subject is dark, you may decide to live with them and do nothing. If the main subject is light, the easiest thing to do is change the flash exposure compensation (the big dial at the bottom right of the back of the housing) to be anywhere from -1/3 to -1 stop.

The two great things about digital photography is instant feedback on the shot in the LCD (which is nice and big on the D300) and the fact that taking another shot (or another 20 shots) doesn't cost you anything. You should make use of both of these and experiment with different f/stops, shutter speeds and exposure compensation just so you know what effect each has. Also, once you have the images on the computer, consider which ones look best and what settings you used (under the prevailing conditions). This is all good information which will help you improve your technique. While it is nice to get shots right first time, every time, in most cases it doesn't matter if your best shot is the first one or the 50th.