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Common Lizards 2014 |
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GemmaJF
Admin Group Joined: 25 Jan 2003 Location: Essex Status: Offline Points: 4359 |
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GemmaJF
Admin Group Joined: 25 Jan 2003 Location: Essex Status: Offline Points: 4359 |
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Are my two favourite subjects going to pair up???
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GemmaJF
Admin Group Joined: 25 Jan 2003 Location: Essex Status: Offline Points: 4359 |
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Going macro!
Any thoughts on macro lights? Seem very expensive but I'm still pushing for DOF and shutter speeds are slow with the available spring sunshine? I wondered though if they are the cause of white 'rings' in the eyes of reptiles in some pictures I've seen? Edited by GemmaJF - 12 Mar 2014 at 4:41pm |
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will
Senior Member Joined: 27 Feb 2007 Location: United Kingdom Status: Offline Points: 1830 |
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I bought a cheap ring flash for the macro last year, and the results looked, well, cheap... negligible benefit IMHO..
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GemmaJF
Admin Group Joined: 25 Jan 2003 Location: Essex Status: Offline Points: 4359 |
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Cheers Will, suppose I could have used the built in flash at least in the last one to fill in the shadows. For some reason I've yet to understand, when I use flash in Av mode it locks the shutter speed to 1/200 which is kind of worse Might be my naivety behind the lens, but I thought flash would be more light, faster shutter for a given aperture??
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Tom Omlette
Senior Member Joined: 07 Nov 2013 Location: Stoke on Trent Status: Offline Points: 449 |
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flash is pretty much essential for bugs and really small stuff. partly because of the closeness to the subject which reduces the amount of light available but mostly because dof becomes so shallow that it is difficult to get useable results from anything under f11.
the issue about max shutter speeds with flash is complicated and i'm not sure i really understand it but here goes: every camera has a flash sync speed which is the max shutter speed when using flash. canon is 1/200th. this is to avoid black underexposed sections that you would otherwise get. the shutter is actually made up of two 'curtains' one opens from top to bottom to expose the sensor then a second closes from top to bottom. however, at faster shutter speeds it works differently and the second curtain starts to close before the first one has finished opening all the way. this means that they sort of form a slit traveling down the sensor letting light in as they go. faster shutter speed = smaller slit. thats fine in ambient light which is constant but flash is a burst of light anything from 1000th to 20000th of a second. your canons sync speed is 200th that means the whole sensor can be exposed for a maximum of 200th of a second. after that the slit thing starts to kick in. then if you use flash with a higher shutter speed a proportion of light (more there faster the shutter) will be blocked by the downward travelling curtains and you will end up with sections at the top and/or bottom completely un or underexposed. the only way around this is with an external flash which can emit a pulse of light rather than a burst. i have tried this however and images are very underexposed. ironically the technique is used more in bright light for fill in flash rather than when the flash has to provide most of the light required. hope this helps. btw super sharp close up tim
Edited by Tom Omlette - 12 Mar 2014 at 8:06pm |
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will
Senior Member Joined: 27 Feb 2007 Location: United Kingdom Status: Offline Points: 1830 |
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er, yeah Gemma, what Tim said...
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GemmaJF
Admin Group Joined: 25 Jan 2003 Location: Essex Status: Offline Points: 4359 |
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Thanks Tim, didn't have a clue about any of that, so thanks for a great explanation.
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Tom Omlette
Senior Member Joined: 07 Nov 2013 Location: Stoke on Trent Status: Offline Points: 449 |
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if you're still unsure about anything prob best to google flash sync speed than get me to clarify lol!!!
people tend to prefer either twin macro flashes with diffusers or a normal external flash with home made diffusers that channel the light to the subject rather than ring lights which are thought to give harsh light and as you say can result in obvious refections in the eye. i like this guys stuff. he seems to use flash for everything although he does a lot of his work at night http://orionmystery.blogspot.it you can clearly see the reflection of his flash but i think its ok tim
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GemmaJF
Admin Group Joined: 25 Jan 2003 Location: Essex Status: Offline Points: 4359 |
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oooh! They are really good! I've just blown my pocket money on some extender rings, but I've been looking at the canon Twin Lite MT-24EX but its's way out of my budget new. I'll have to look at rings too, maybe there is a suitable one at a more affordable price.
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