The setup was simple, one flash (580EX II) set on E-TTL and a shoot through umbrella camera left, the camera was set to fire the 580EX II with the popup flash output disabled, i.e. it will only act as a trigger and will not fire during the actual exposure.
To my surprise I found that all of the pictures I took had the popup flash appearing in the eyes of my subject, I double checked everything and you can see both the umbrella's and the popup flash catch lights, why does the popup flash appear in the actual exposure? It is supposed to send pre-flashes only!!!
The fix in post is really easy and only took 5 seconds per photo, but I was really pissed off, I will start searching to see if other people are facing the same issue. I faced other limitations as well with this shoot but that's for another article.
It's the same issue with Nikon. One solution is the SG-3IR infrared panel. It's made by Nikon but apparently it's also possible to use it with Canon (with some modification)
ReplyDeletehttp://photography-on-the.net/forum/showthread.php?t=785999
An alternative that works for Nikon and may work for Canon is to shoot above the sync speed. With Nikon, the popup flash has no HSS so the flash from the popup doesn't appear.
I hope this helps!
Best regards,
Mic
Same problem with Master mode on the Nikon D90. It gets really bad with in dark environments with close objects, where the Master mode contribution of the pop-up flash is prominent and creates a horrible lens hood shadow.
ReplyDeleteThe official solution is the SG-3IR panel, as Mic Ty wrote, but that's a bit cumbersome.
My soution is to stick a small IR gel filter on the pop-up flash. To make an IR filter out of standard gels, you can get a sheet of Rosco's "Roscolux Medium Gray" gel (Adorama item RO98, $6.50) and stack 4 layers: that reduces visible light by 4 steps, but lets through most of the IR (look at the transmission spectrum curve -- it goes up towards the red side). Or, if you have a Roscoe sample pack, just look for a few gels of different hue whose transmission curves approach 100% on the red side, and stack them. Works great and has a very small effect on signal range.
Attaching gels to a the pop-up flash is a bit tricky -- I use a velcro had some careful folding.
Because of this problem (especially the pop-up shadow), I always use this IR filter with optical triggering, unless I'm intentionally using the pop-up for fill flash.
Thanks both Mic and Opt, after a bit of research it seems that I am not alone, I will certainly try both Mic's HSS and your gel solutions and report back of my findings, the Nikon solution requires me buying from Amazon and shipping over to Egypt which is both a hassle and will be expensive (especially that I already have radio triggers).
ReplyDeleteWhat I was wondering about is the gel color, I never bought any gels, I downloaded a PDF with the standard gel colors then printed it on a transparency paper then cut them, I wonder if I can find the medium gray color.
But thanks for the idea, will definitely try it.
mshafik, that's an interesting approach to gels. How well do these home-made gels survive the heat and light intensity of flashes? Did you use a color-calibrated path to print them? Are you assuming that the PDF files are in sRGB color space?
ReplyDeleteIt probably won't work for IR filters, though: your printer will only try to approximate the colors in the visible spectrum, and who knows what is the infrared spectrum of the printer's ink/pigments...
A popular trick for cheap IR filters is to use developed unexposed slide film (or developed fully-exposed negative film).
About gel availability, I know what you mean - I'm in Israel and it's hard to find this stuff here too. But I have some spare CTO and Medium Gray (cut from large sheets) that I can send you. If you have a use for them, let me know and I'll contact you privately for your mailing address. It would be interesting to compare Rosco CTO to home-printed CTO.
Hey Opt, you just gave me an idea to a new post, I didn't give much thought to home made gels vs real gels, I will quickly answer some of your questions then I promise you to do a full post about these home made gels, my next post will be about my newly acquired 580EX II flash then the next one will be the one about the gels, and I think I will do one more flash post with the new honeycomb grids that I got.
ReplyDelete- I never had any problems with heat, I printed on the transparency papers that are used for old projectors, these projectors usually generate more heat for extended periods of time.
- I assumed the PDF was sRGB (I will share it in the post), and I used a color laser printer.
- They work pretty well for me, I don't believe you need 100% accurate gels since the tungsten bulbs already have vastly different color temperatures, and at the end of the day I shoot RAW and adjust the WB in post.
Thanks for your offer about sending the gel sheets, I will probably get back to you on this one.