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MitHere

Why are my photos under and overexposing?

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Hi guys

I'm in Fiji at the moment and I'm diving with a Canon G11 and Canon housing with an Inon S2000 strobe.

I'm trying to shoot in manual macro with around 1/1000th and F8.0 and either have my strobe set to S-TTL or manual and have tried changing the strobe power. Using the diffuser too.

basically my problem is that most photos either come out overexposed and washed out... Or it's like the shutter speed is too fast and the light hasn't had enough time to light up the whole picture.. But surely light speed beats shutter speed.

I don't think strobe positioning is a problem... So what else can it be?

I tried going from even 1/60 to 1/2000th on yesterday's dives but I'm still not getting anything close to what I want - bar one of a gorgonian sea fan (Which looked rad except for... Half the picture being dark!) and a red soft coral which was all light up but looked like it was too overexposed in the corner where the strobe is.

So help me please so I can wow you guys when I alter the RAWs when I get back!

Cheers :goodpost:

*Edit* I *am* pointing the strobe directly at the subject or near enough. Maybe this is the problem? I want just the edges of the 105 degree or so angle of coverage lighting the subject, yes? ;)

Edited by MitHere

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It's hard to say without seeing some examples. But off the top of my head:

 

- I remember reading (I haven't had a G series since the G7) that TTL flash won't work when the camera is in manual mode. If this is the case you'd either need to shoot with the strobe in manual or the camera in Av or Tv mode (someone correct me if I'm wring here please)

 

- Strobe sync speed will vary depending on your camera, but with most the highest shutter speed you could go would be 1/250

 

- are you using a diffuser on the strobe?

 

- could also be strobe placement. If you can post some examples it may help.

 

Good luck with it

 

Ryan.

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Yes, I'm not a G Series user but also recall reading that TTL doesn't work in manual mode.

 

For full manual with a strobe you are balancing two light sources. The background will be exposed by a combination of shutter speed and aperture whilst the foreground will be exposed by a combination of aperture and strobe power (with distance)

 

Start off with the aperture you want (maybe f/8 - f/5.6) then set the shutter speed to correctly expose the background blue (maybe 1/60 - 1/200) Adjust the strobe to give the correct foreground exposure depending on distance. You don't say which strobe you are using but even the largest strobe is only effective up to around 6 feet.

 

For macro without any distant background, the shutter speed will make little difference unless you do something extreme with it; unless you have fast moving subjects keep it around 1/125. AV mode + TTL should work well once you have figured any +/- EV adjustments that your set up might need.

Edited by Balrog

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The G series does not support TTL in Manual mode. Have you made sure you have the magnet in the correct place for the pre-flash? Try taking a picture of yourself in the mirror with the camera and you should be able to see the flash in the picture.

 

Good luck!

 

Mark

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Your camera and strobe cannot sync with the high shutter speed. That is why 1/2 your picture was dark. The shutter was closing before the flash went off. Also, your camera will not do TTL in manual.

 

If you want manual control, try 1/125, F8 and ISO 100, 2-3 ft from a stationary target. Then vary your strobe manual power until the exposure looks good. Then you can adjust from there. If you get above 1/250 shutter, your camera will not sync with the flash.

Your camera does not pre-flash in MANUAL mode but does in other modes. Make certain you have the strobe in/out button matching your setting.

 

If you want TTL, try using Program, Shutter (1/250 or slower) or Ap. priority with TTL. You lose the ability to control some things in these modes but your exposures should come under reasonable control. The camera will pre-flash so the strobe must be set for that - right button on strobe pops in/out for changing this setting.

 

As mentioned above, test fire into a mirror and the flash should show in the picture. You might try a test fire in a very dark room in one of the recommended settings (not manual) and the exposure should be close for things in range of the flash strength.

 

The question is not light speed vs shutter speed. Its shutter speed vs time to fire strobe.

If you are really close to the subject, TTL sometimes has trouble stopping the strobe before the picture is washed out. Moving the strobe (not the camera) further away might help. Your strobe has the 'A-B-C' switch so you can move strobe power up and down in STTL mode if you need more or less power - once you are in the right mode with the camera - and the in/out button matches the pre-flash.

 

The non-manual modes are often easier to start and you can use STTL for exposure control with the flash. Its not perfect in all situations but it works for most and certainly has higher success than you are having now.

 

Hope that helps

Dave

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Alright, got ya. Slower shutter speeds and try to get my strobe a little bit away from the subject.

Why isn't my strobe and shutter syncing though?

To the above I'm using an Inon S2000!

Unfortunately no time for the mirror test, it's dive time! :goodpost:

Thanks fellas

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Why isn't my strobe and shutter syncing though?

Here is a copy/pasted online definition for you:

Flash synchronisation, typically referred to as flash sync, is a means by which a flash head is fired at precisely the moment when the camera's shutter is at its peak opening.

 

The camera has a coordination time for sending the signal to the strobe and matching it to the shutter. It varies with the camera. Your's has a max. of 1/250.

 

In Av mode, the G11 will set max shutter to 1/60 for flash sync and you get TTL available. This shutter limitation is frustrating and Canon forces it upon you. It should be able to go to 1/250 but it will not.

 

In Tv mode, you can set shutter up to 1/250 for flash sync and you get TTL available.

 

In Manual, if you go faster than 1/250, you will often get partial lighting from the shutter being partially closed when the flash is fired.

And you get no TTL with the camera in manual so if you are setting the strobe to STTL and the camera to Manual, you have no control of strobe power.

 

No time for a mirror test? Once setup for diving, just face a mirror, fire the camera w/ flash, and review the results on the camera back. Takes about 5 seconds.

 

I sent you a PM as well with more comments.

Dave

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Hi dave,

 

interesting comments. I have a g11 and a z240 and a d2000 and will be diving with it in June. If I'm shooting manual mode in the camera with no ttl does this mean I shouldn't have the strobes set on either the sttl or sttl low setting?

 

I was also intrigued about your comment about pre flash in the different modes. My z240 I can click the switch to change this setting but the s2000 I have a magnet and alen key. This effectively restricts me to one mode if I want to use both strobes.

 

Based on your comments above, am I right in assuming that in programme auto mode you will get ttl upto 1/250 if you can get the camera to shoot that quick in P mode..!

 

I had planned to shoot manual with the camer with the option of switching to either programme mode or appeture priority if I was struggling with manual, I am now unsure of the best option..

 

Cheers,

mark

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In Manual, if you go faster than 1/250, you will often get partial lighting from the shutter being partially closed when the flash is fired.

And you get no TTL with the camera in manual so if you are setting the strobe to STTL and the camera to Manual, you have no control of strobe power.

Hiya,

 

According to Canon the G11 with sync at speeds of up to 1/2000s. It has an electronic shutter. I recall Jeremy posting photos from his G series using 1/1000s etc. I think it was in a discussion about achieving black backgrounds.

 

From Canon website - G11

post-22909-1270656533.jpg

 

 

The partial lighting sounds more like the wrong sync setting on the strobe.

 

One thing to bear in mind is that at very fast speeds the strobe does not get to its maximum output before the shutter is closed.

 

Instead of a mirror just point the strobe directly at the lens and take a shot, if the frame blows out white, the flash is synced..

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Hiya,

 

According to Canon the G11 with sync at speeds of up to 1/2000s. It has an electronic shutter. I recall Jeremy posting photos from his G series using 1/1000s etc. I think it was in a discussion about achieving black backgrounds.

 

From Canon website - G11

post-22909-1270656533.jpg

 

 

The partial lighting sounds more like the wrong sync setting on the strobe.

 

One thing to bear in mind is that at very fast speeds the strobe does not get to its maximum output before the shutter is closed.

 

Instead of a mirror just point the strobe directly at the lens and take a shot, if the frame blows out white, the flash is synced..

 

yeah, I used the camera in manual and the strobe in manual too... with fast shutter speeds I put the strobe to max and slower SS I dialed it down but the result was the same. When I get home I'll chuck the photos up and you guys can hopefully help? :goodpost:

I remember seeing the Slow Sync bit only in Av and tv modes.. Not manual ;)

Edited by MitHere

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yeah, I used the camera in manual and the strobe in manual too... with fast shutter speeds I put the strobe to max and slower SS I dialed it down but the result was the same. When I get home I'll chuck the photos up and you guys can hopefully help? :goodpost:

I remember seeing the Slow Sync bit only in Av and tv modes.. Not manual ;)

Hiya

 

Ignore slow sync (it was just to show 'fastest 1/2000')

 

Ok, Basically for your camera and strobe you have 2 different situations going on...

 

1. P, Av, Tv - The flash will fire in TTL mode. For TTL to work it will fire a preflash. This is so close to the 'real' flash that you may not see it by eye. Your strobe needs to ignore the preflash and sync with the main flash. You can check this by either taking a photo looking into a mirror or pointing the flash directly at the lens and taking a picture. When the 2 are correctly synced you will see the flash in the mirror and/ or the picture will white out.

 

2. In manual mode the flash is also manual (ie no TTL) so it will only deliver the full flash (no pre flash) You will need to select a different setting on the strobe for this to sync correctly.

 

Remember if switching between the 2 you need to change BOTH the camera and the strobe to maintain the sync.

 

 

Shutter speed should not really effect the flash exposer. It is difficult without seeing examples, however:

 

Aperture adjustments affect the foreground and background exposure

 

Shutter speed adjustments affect background exposure

 

Therefore, set aperture for desired depth of field, adjust power and or position of strobe to correctly expose foreground, adjust shutter speed to control ambient light. Fast shutter = dark background, slow shutter = light background.

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I had planned to shoot manual with the camer with the option of switching to either programme mode or appeture priority if I was struggling with manual, I am now unsure of the best option..

 

Cheers,

mark

Mark,

I think Duncan summed it up quite nicely. So I will not repeat his comments or variations thereof.

 

Since your magnet requires a wrench, etc and not really an option during diving, seems you need to select MANUAL or not before diving - as you have realized. As to which option is better for you, depends on you and your situation. Your situation is a bit more complicated as you are balancing 2 strobes that do not match. The setting for one will most likely not be the setting for the other if shooting in manual. You may have to adjust a bit even in TTL for the difference as well.

 

If you use wide angle wet lenses, TTL might be harder to get consistent but not impossible. If you have the luxury of time, you can adjust exposure compensation up or down as needed based on trial and error on the subject.... if its stationary...such as a coral/sponge arrangement.

 

If you shoot fish portraits and small macro related subjects, I always thought TTL worked pretty well. With relatively stationary macro subjects, I try to do test fires and exposure adjustment in advance on a nearby target with no fish/nudi present...then when all is set, move up to the real subject. This keeps me from running them off with a bunch of flashes and keeps me from moving the camera around right on top of them while I make adjustments.

This also works well when shooting rays in the sand. They will often let you drift by slowly while shooting and let you get fairly close. But will not tolerate you stopping and messing with settings. I really do not want to drive them to get up and move from my presence.

 

Hope that is some help.

Dave

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Im wondering if something else might be involved too like redeye reduction in the flash settings being turned on, or the attachments of the fibre optic connector being a bit unreliable? Also wondering if auto-iso is on rather than using a set ISO?

 

Looking at the manual, this camera has a lot of options meaning you can end up changing things that make things worse while trying to figure things out.

 

I would try getting everything set to manual, set the camera to 1/1000 and f8, ISO to 100 then in the camera flash settings try using manual on the camera flash (p106 of the manual), first curtain, set safety FE off, set the camera flash output to as low as possible, set the strobe to 'manual', then take pictures, trying all the different strobe power levels with the exposure dial - on Inon they can be bit confusing sometimes what increases and what decreases the power level depending on the setting, oh and have the magnet set to 'no pre flash'.

 

Do this above water with a set target at a set distance (say a foot) and keep working at things till you can reliably increase or decrease the strobe output levels to change the lighting level on your target and get it to a reasonable light level, as well as reliably making it darker or lighter by changing the strobe power level. Make sure you give the strobe and camera a chance to recharge in between shots and dont do too many shots quickly in a row or you could overheat the strobe.

 

You need to get a recipe that works above water, trying to figure it out underwater will just give you migraines.

 

Otara

Edited by Otara

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Thanks guys,

 

Some interesting thoughts there. Definatly going to need to do a lot more experimenting. I dont get in the water very often so im glad ive stumbled across this now giving me plenty of time to get comfortable with what I need to do when the time comes.

 

I was disapointed last year with my results from my G9 and z240 and I assumed it was to do with not having the strobe setup correctly, now I know exactly what it was I had wrong :s

 

Sounds like my best bet is to master manual mode... ive picked about f4 and 1/100 for WA and f8 and 1/250 for macro as a start point....

 

Mark

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Thanks guys,

 

Some interesting thoughts there. Definatly going to need to do a lot more experimenting. I dont get in the water very often so im glad ive stumbled across this now giving me plenty of time to get comfortable with what I need to do when the time comes.

 

I was disapointed last year with my results from my G9 and z240 and I assumed it was to do with not having the strobe setup correctly, now I know exactly what it was I had wrong :s

 

Sounds like my best bet is to master manual mode... ive picked about f4 and 1/100 for WA and f8 and 1/250 for macro as a start point....

 

Mark

After quite a bit of experimentation ... and some guidance from Cathy Church's staff, my starting points with the G9 were:

 

MACRO - f/8 and 1/1000th (or even 1/2500th) for 'black' water

 

W/A - f/5.6 and 1/125th always gave me nice blue water on sunny days

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Thanks Jeremy,

 

Thats quite a bit faster than I had considered for Macro work. What strobes were you using with that, will I have problems getting the correct exposure?

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Thanks Jeremy,

 

Thats quite a bit faster than I had considered for Macro work. What strobes were you using with that, will I have problems getting the correct exposure?

I had a YS-27dx and a YS-110. I had no trouble lighting macro at those settings ...

 

This was shot with that exact setup at f/8 and 1/2500th and I think each strobe was at about 1/2 power - note the very dark water ...

 

4470543681_0f790d63d6.jpg

 

Here's a macro shot using my w/a settings - which I did because I wanted bright blue water ...

 

2623453380_8b2874c8d3.jpg

 

... and here's a w/a at the w/a setup ... strobes on full I think.

 

2623417346_e8ea94dd6a.jpg

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Thanks Jeremy,

 

I like the very black background. Looks like im going to be altering my defaults. I will of course be experimenting as well. Think I need to try and get in a pool somewhere if I can before I get out to Egypt in June for a bit of practise without having to worry about being cold and clunky with all the gloves etc in UK waters...!

 

Mark

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1-Shoot in Manual, RAW

2-Set the camera on f/8 and the shutter at 1/125. Strobes parallel to lens, level with port and about 8" away from port. Take a shot of the water (background). Increase to darken. If you like black set the shutter speed to 1/250, not faster. Shutter not lower than 1/80. Get the background that you like at F/8.

 

3-Set the strobes on 1/2 power. Diffuser on .5 stop. Point the strobes parallel and level to the lens about 8" away from the lens port. From about 2' take a shot of a stationary object with a water background. Reduce f/stop (open up) if foreground is underexposed, increase F/stop if over exposed. If you need to open up (smaller F/stop) past f 5.6 increase strobe power. If this still isn't enough light move strobes closer and/or point towards the subject. Ultimately you will get an exposed foreground that you like at a particular distance, strobe power, and f/stop.

5-Now find a stationary macro subject. Move shutter to 1/200-1/250, strobes parallel, close to port, f/stop f/16, strobe at 1/2 power. Distance from subject at 4-6". Repeat until you have proper exposure f/stop to f/22 as required. F/stop NOT below f/11. Higher is better.

 

The above should take less than 10 miniutes. You now have proper settings for these conditions. You can now vary these settings for different conditions

 

It is best to have some strobe headroom. If you get a working solution at 1/2 power, 2' distance, F/8, you can properly expose shots at 3' with full power and/or f/5.6.

 

This is not rocket science. It just takes a logical process.

 

Tom

Edited by TomR1

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Hi hi, these are the unprocessed photos from the RAWs I took in Fiji...

Maybe you guys can better see what's going wrong apart from the fact I'm not really getting close enough in most photos! ;)

It does just look to me that either the SS isn't fast enough and they're a bit blurry or the strobe and shutter aren't synced properly in manual (Most of these photos were in manual if not all!)

http://img176.imageshack.us/img176/4503/img1398k.jpg

http://img710.imageshack.us/img710/78/img1409o.jpg

http://img517.imageshack.us/img517/1646/img1446po.jpg

http://img10.imageshack.us/img10/9747/img1466e.jpg

http://img180.imageshack.us/img180/1070/img1490v.jpg

http://img202.imageshack.us/img202/7002/img1497qh.jpg

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Hi MitHere,

any chance of posting the Meta-data from a couple of the images, perhaps one over-ex and one under-ex? I agree with what Otara

mentioned earlier and think you may have the cameras flash set to Red-Eye Reduction which buggers up the camera-strobe communication with

a different Pre-Flash sequence. A friend of ours had a similar issue with his G10 until we diagnosed the issue after seeing the Meta-Data from his

images. Once he switched off the Red-Eye he started getting consistent exposures instead of his strobe doing a full dump most of the time.

 

Cheers,

Jim.

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If you like black set the shutter speed to 1/250, not faster.

 

Sorry ... bad advice.

 

Why are you advising NOT to go past 1/250?

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Hi hi, these are the unprocessed photos from the RAWs I took in Fiji...

Maybe you guys can better see what's going wrong apart from the fact I'm not really getting close enough in most photos! :D

It does just look to me that either the SS isn't fast enough and they're a bit blurry or the strobe and shutter aren't synced properly in manual (Most of these photos were in manual if not all!)

 

I think strobe positioning could be your problem.

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I checked the metadata on your images and Jim is correct in suggesting you have the redeye reduction on.

Try turning it off and shooting the camera in manual mode rather than program.

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