Comments on: manual flash / TTL flash http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/ various writings on photography, whether techniques, ideas, equipment info, or just rants. Wed, 20 Aug 2008 20:26:53 +0000 http://wordpress.org/?v=2.5.1 By: Chris C http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1470 Chris C Thu, 03 Jul 2008 10:00:08 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1470 oh and PS, FYI....i did read the manual like 3x now, my brain just chose to ignore the parts that actually explained the reason hehehehe...... ;) oh and PS, FYI….i did read the manual like 3x now, my brain just chose to ignore the parts that actually explained the reason hehehehe…… ;)

]]> By: Chris C http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1469 Chris C Thu, 03 Jul 2008 09:59:01 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1469 simple yet profound hehehehe.....thanks so much Neil, i know youre used to the compliments by now but it really is true. Youve made us all better photographers. Thanks so much for helping us, your time is gold and you still help those in need. KUDOS to you! simple yet profound hehehehe…..thanks so much Neil, i know youre used to the compliments by now but it really is true. Youve made us all better photographers. Thanks so much for helping us, your time is gold and you still help those in need. KUDOS to you!

]]> By: Neil http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1465 Neil Thu, 03 Jul 2008 08:14:49 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1465 <blockquote>Chris, Your problem is that you worked outside the range of what your flashgun is capable of. Not only do flashguns have a maximum range, but they also have a minimum range, within which the circuitry just can't switch off in time to control your flash exposure. At 1600 ISO, and f4, your 580EX will give you a mimimum of around 3 meters .. which is approx 10 ft. Since you were about 6 ft away, you were simply too close for the flash to control your exposure. So I have two pieces of good news for you. a. There is nothing wrong with your flashgun. b. You're going to spend some more time with your 580EX manual. ;) Neil vN</blockquote>

Chris,

Your problem is that you worked outside the range of what your flashgun is capable of. Not only do flashguns have a maximum range, but they also have a minimum range, within which the circuitry just can’t switch off in time to control your flash exposure.

At 1600 ISO, and f4, your 580EX will give you a mimimum of around 3 meters .. which is approx 10 ft. Since you were about 6 ft away, you were simply too close for the flash to control your exposure.

So I have two pieces of good news for you.
a. There is nothing wrong with your flashgun.
b. You’re going to spend some more time with your 580EX manual. ;)

Neil vN

]]> By: Chris C http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1464 Chris C Thu, 03 Jul 2008 06:17:29 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1464 Hi Neil. Ive always thought the same regarding TTL flash (iso and aperture not influencing the exposure but a few months ago i happened onto a problem which totally baffled me) I tried to do this. I set up the room to be totally dark meaning i shot very late at night, windows closed and no light whatsoever. I put a white pillow up with stripes for focus locking. i put my camera(30D) to shutter of 1/200 and Aperture of F4. I was around 6 feet away from the pillow. I shot at iso 100 and then shifted to iso 1600. The ISO 1600 was overexposed and i cannot explain why. This is shooting with the flash gun (580 EX version 1) direct with no diffusers. The funny thing is, if i bounce the flash, the exposure will be the same, if i pull down the diffuser, the exposure will be the same. If i remove the flash gun and use the onboard flash the exposure is very near each other. In this case, the ambient did not affect my expposure because i shot a iso 1600 frame to check if any ambient was contaminating my exposure and the frame came out all black. can you please shed some light on this, ive been trying to wrap my head around this for like 2 months now. I sent in the flash for checkup and canon did not find anything wrong with it. Thanks Neil. Hoping you can finally give me peace of mind regarding the matter. Hi Neil.

Ive always thought the same regarding TTL flash (iso and aperture not influencing the exposure but a few months ago i happened onto a problem which totally baffled me)

I tried to do this. I set up the room to be totally dark meaning i shot very late at night, windows closed and no light whatsoever. I put a white pillow up with stripes for focus locking.

i put my camera(30D) to shutter of 1/200 and Aperture of F4. I was around 6 feet away from the pillow. I shot at iso 100 and then shifted to iso 1600. The ISO 1600 was overexposed and i cannot explain why. This is shooting with the flash gun (580 EX version 1) direct with no diffusers.

The funny thing is, if i bounce the flash, the exposure will be the same, if i pull down the diffuser, the exposure will be the same. If i remove the flash gun and use the onboard flash the exposure is very near each other.

In this case, the ambient did not affect my expposure because i shot a iso 1600 frame to check if any ambient was contaminating my exposure and the frame came out all black.

can you please shed some light on this, ive been trying to wrap my head around this for like 2 months now.

I sent in the flash for checkup and canon did not find anything wrong with it.

Thanks Neil. Hoping you can finally give me peace of mind regarding the matter.

]]> By: Neil http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1236 Neil Fri, 16 May 2008 03:49:24 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1236 <blockquote>HI there ... The difference in exposure that you're seeing now is because your ambient light exposure is now changing as you vary your aperture. This isn't a negative ... it's just an indication that you now have a LOT more flexibility in mixing flash with ambient light, and doing so on the fly. Regarding your other questions ... Yes and no. It all depends. Centering the needle of your exposure meter in your viewfinder does not necessarily mean you have correct exposure. It all depends on the tonality of your scene. Zeroing the needle will give you the same results though as any of the automatic metering modes. Read these series of articles to see if this all makes more sense: http://planetneil.com/tangents/exposure-metering/ Neil vN</blockquote>

HI there …

The difference in exposure that you’re seeing now is because your ambient light exposure is now changing as you vary your aperture.

This isn’t a negative … it’s just an indication that you now have a LOT more flexibility in mixing flash with ambient light, and doing so on the fly.

Regarding your other questions … Yes and no. It all depends. Centering the needle of your exposure meter in your viewfinder does not necessarily mean you have correct exposure. It all depends on the tonality of your scene. Zeroing the needle will give you the same results though as any of the automatic metering modes.

Read these series of articles to see if this all makes more sense:
http://planetneil.com/tangents/exposure-metering/

Neil vN

]]> By: Yap Tsok Sam http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1222 Yap Tsok Sam Thu, 15 May 2008 15:08:40 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-1222 First of all thanks for sharing. I've just ventured into flash photography after reading your blogs. very informative and definitely a must read site for any photographers who wish to learn flash photography. However, i've tried the experiment you suggest above that with TTL flash, our chosen aperture and ISO does not affect our exposures. I shot using manual exposures and change the aperture from 4, 5.6 and 6, but every shot i got is slightly different in exposure. Doesn't that means my exposures got affected evrytime i change the aperture? Do i need to use direct flash or bounce for this experiment? Also, when i meter an object using in-camera meter(manual exposure), do i need to keep the exposure indicator in the view finder at the center to get proper exposure? hope you can help me to clarify this, please..... thanks. First of all thanks for sharing. I’ve just ventured into flash photography after reading your blogs. very informative and definitely a must read site for any photographers who wish to learn flash photography.
However, i’ve tried the experiment you suggest above that with TTL flash, our chosen aperture and ISO does not affect our exposures. I shot using manual exposures and change the aperture from 4, 5.6 and 6, but every shot i got is slightly different in exposure. Doesn’t that means my exposures got affected evrytime i change the aperture? Do i need to use direct flash or bounce for this experiment? Also, when i meter an object using in-camera meter(manual exposure), do i need to keep the exposure indicator in the view finder at the center to get proper exposure? hope you can help me to clarify this, please….. thanks.

]]> By: planet neil - tangents » so, what are your settings? http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-956 planet neil - tangents » so, what are your settings? Thu, 27 Mar 2008 08:31:02 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-956 [...] were then 4 factors controlling the flash exposure.  This topic was covered in two recent posts: manual vs TTL flash // juggling shutter speed, aperture, ISO.   (And if anyone is interested in the specific [...] [...] were then 4 factors controlling the flash exposure.  This topic was covered in two recent posts: manual vs TTL flash // juggling shutter speed, aperture, ISO.   (And if anyone is interested in the specific [...]

]]> By: mad http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-948 mad Wed, 26 Mar 2008 06:32:37 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-948 thanks neil- this is the best site yet! thanks neil- this is the best site yet!

]]> By: Neil http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-874 Neil Wed, 12 Mar 2008 03:41:27 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-874 <blockquote>Severoon ... I actually do have a book contract, and am in the process of writing one. Hopefully it will be out by the end of the year. I will most definitely announce it here on this blog when it does come out. thanks Neil.</blockquote>

Severoon …

I actually do have a book contract, and am in the process of writing one.
Hopefully it will be out by the end of the year.
I will most definitely announce it here on this blog when it does come out.

thanks

Neil.

]]> By: planet neil - tangents » “Dragging the Shutter” revisited http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-802 planet neil - tangents » “Dragging the Shutter” revisited Sat, 01 Mar 2008 01:31:46 +0000 http://planetneil.com/tangents/2007/12/26/manual-flash-ttl-flash/#comment-802 [...] explained on these two previous pages ..  - Manual flash vs TTL flash,  - juggling the three controls .. TTL flash exposure will follow your chosen aperture and ISO. [...] [...] explained on these two previous pages ..  - Manual flash vs TTL flash,  - juggling the three controls .. TTL flash exposure will follow your chosen aperture and ISO. [...]

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