spaco

Accuracy of Glowing iron on video camera

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spaco   

Over the years, I have shot many videos of blacksmiths beating on hot iron and I have seen a lot of 'em, too.  But, what the camera sees and what I see with the naked eye aren't even close, as relates to the glowing color of the material being worked. 

Is it just me?  I think not.

There are many reasons why this disparity can be an issue.

The main problem, as I see it. is that beginning blacksmiths won't realize this problem.  To them, the smith appears to be:

-taking the iron out of the fire at a completely white heat and then;

-beating on it for a really long time while the metal seems to stay bright red forever!

When, in actuality (viewed by the human doing the work or by a bystander) the metal is several hundreds of degrees cooler that it appears on the video.

And, in reality, while the metal appears to be still glowing on the video, the smith is actually planishing a piece that doesn't  appear to the naked eye to be glowing at all.

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So, what, if anything, do the videographers amongst you do about that?

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The reason that I am asking today is that I have been messing around with a $35.00  1000 watt induction heater from China for the last couple of months and I am having trouble duplicating the results that I APPEAR to see on youtube videos that demonstrate its use.  They show, for instance, a small graphite crucible becoming white hot, when, to my eye on the bench, it is barely glowing at all.  But NONE of the videos give a complete picture of their setup and I don't think any of those producers understand metallurgy at all.BTW, don't get all excited about this cheap induction heater just yet.  It runs a too high a frequency (about 100 Khz) to get iron hot enough to do any real forging.

Pete Stanaitis

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Glenn   

First you need to know the latitude of the recording device and the recording media, as well as the recording spectrum. Many of the cameras see and record beyond the human eye spectrum. Some of this can be filtered out. 

The other issue is the range or ratio of brightness between forging or welding heat and ambient light of the blacksmith shop. This can be adjusted by raising the ambient light of the shop or subject and background.

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JHCC   

Glenn, what kind of filters would you recommend? All of the articles I've found on filtering IR, for example, focus on removing IR filters, to photograph in non-visible light.

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It goes beyond just filters..   The problem is calibration of all items used in the process..  From camera to computer to TV's to cell phones.. Etc etc.. Each has there own color palette (Gama) and spectrum of colors the software converts to.. 

White balance on the camera and the ambient light as well as iris of the camera and lens play in..  The 3D cameras I have been using work great when there is ample ambient light but as the lighting fades it starts getting brighter as the CMOS sensor starts trying to scavenge more light (algorithm).. so the image takes on a halo effect.. Once the the bright metal  drops off enough the color seems to get a closer to what I am seeing in person but you can't see anything in the back ground details are washed out..

Once the ambient light is bright enough then you have to mess with ISO settings and F stops ..  I find it is even different between camera.. 

I do find that camera today try to do a better job at processing the colors without filters vs my Digital 8 camera but back then it was going from Digital 8 to VHS  or I should say Super VHS...  

My Samsung S7 edge shoots amazing video... With a few of these set to HDR It might actually produce a decent film..  The footage on the chain making video of the forge with chain ring inside was shot with the S7 and the chain ring with flux on it.. 

On video I shot few days ago with both cameras set exactly the same, the video was brighter on one vs the other.. 

When I can come up with 4000.00 I'll buy some new video cameras

 

 

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