Yoshizen's Blog

Slide Duplication / Digitization using Flash-light

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They are the samples, which were Digitized on fluorescent light-box = I talked about before. 

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But photos above were digitized using a TTL flash-light.

( They are in large size = click to enlarge and see the details (but ignore the dust ) 😉

It’s not too bad in highlight tone. ( in the shadow, some noises due to “Brighten-up” )

If anybody visited here twice, you may noticed that the photos are different from before.

—– I’ve changed them, in fact three times as I was not happy with the color of Dupe. 

What I wrote about [Home-made Light-box] —– as a Slide-viewer, it was correct though,

to use it for Duplication was wrong.   Color was far from ideal = in fact, dreadful. 😀

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I tried to tinker the color temperature etc. still not suticefied, and tried to use LED light

though,  fundamentally fluorescent light and White LED has the same characteristics.  

Whitish color of LED was emitted by the mixture of fluorescent compound, excited by

LED’s near UV light = same as the Fluorescent light tube.  Since it was produced by a mix

of BGR light, its light spectrum has the typical light-spike from its chemical, hence color is

never perfect.  –—- on the end, I came to the conclusion = it’s better to use a flash-light =

its Xenon discharge light which has a continuous light spectrum is much more natural.  

Unlike easily fooled human-eyes, an image sensor in a DSLR pick-up those

peaks and the spikes and produce wrong color which is harder to eliminate.    

 

To use a flash-light for Slide-duplication is not a complicated business.  

Just place a flash under the white perspex (may be 4″ / 10 cm away). —– I cut a 2″ (5 cm)

square hole in the center of 8″ high card-board box then put white perspex on top, and placed

a flash-light inside.  (of cause, flash is aiming to the cut-out hole straight.)

I put some layers of white tissue over the flash face to diffuse and reduce the light.  

I used Canon 430EX-II in the TTL mode but on -1/3 setting. (For High-contrast original, expose -1

and brighten up with after process might be better)  Flash and the Camera was connected by

an “Off camera cable“.  With this set-up, the exposure will be controlled in TTL though, to make

it a bit brighter or darker, it is easier to use a flash with manual setting (with minimum power

setting ) and adjust the exposure by changing F-aperture or ISO setting, as it can be done from

the camera side.  ( To change the setting on the back of flash is more awkward.)


While testing this, what I noticed interesting was that a dupe made by D800 with HDR seemes

not much different from dupe made by C’ 5D Mk-III with flash-light (only one exposure) of

which the shadow was brighten-up by common photo program. = Canon’s image sensor and

their processing engine seemed to have wider Dynamic Range in the first place than Nikon.

(To see the comparison in this post.)  To be fair, this matter needs to have more critical test.

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4 Responses

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  1. bentehaarstad said, on August 28, 2013 at 23:39

    I never thought it would be possible, but you did a great job at it, Yoshizen.

    • yoshizen said, on August 29, 2013 at 00:00

      Thank you Bente. Needs is a mother of invention. 😀
      Hardest part of the job is to dust off —– slide frame with
      glass has 6 surface to clean 😀

  2. elenacaravela said, on August 30, 2013 at 01:53

    Yes, quite a difference in color temperature. Amazing!

    • yoshizen said, on August 30, 2013 at 03:20

      In fact, it also got red = make skin-tone brown if it was dark.


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