Playing with the Yongnuo

[Grumpy John]

I've started this topic to document my endeavours to reduce the reflections I get when using my Yongnuo ring flash to photograph hard surfaces. I have managed to obtain some diffuser material used in skylights and using two different sized hole saws I made some rings which I can cut to fit over the lenses on the flash unit. I also have a piece of frosted acrylic and a home made diffuser

kevinj, this may be of interest to you.

#1 The skylight material.


#2 The frosted acrylic.


#3 The home made diffuser.


I made the diffuser from sandwiching a piece of packing foam between 2 pieces of a cut up opaque document holder.

#4 The foam


#5 The document holder.


#6 I will cut the diffusers to fit over the white lenses. I will use double sided tape to secure the diffusers to the lenses.

[Grumpy John]

The first test shots without any diffuser fitted. Four images using the same settings, except for different metering settings.
All images are virtually SOOC except for lens correction and setting white balance to Flash, this was done in ACR. They were resized using save for web in CC2020. No cropping or any other PP.

f8.0, 1/200, ISO 100. Flash unit set to TTL.

#1 Metering Mode: Evaluative.


#2 Metering Mode: Partial.


#3 Metering Mode: Spot.


#4 Metering Mode: Centreweighted-Average.

[HansE]

Do youhave an observation? I don't see a lot of difference. have I missed something?

[Grumpy John]

My understanding is that the camera does the metering and if you have a compatible TTL flash the flash will adjust its' power to give a correct exposure. I may be wrong, perhaps Isac, or kevinj could join the conversation.

[Grumpy John]

Some reading for you @HansE
https://www.whatdigitalcamera.com/te...-it-work-67370

[HansE]

Understood. Interesting how much technology has gone into the simple flash.

[Grumpy John]

Continuing on with my diffuser experiment I decided against using the berries as the subject matter. As the berries aged their reflective properties changed and as such, the results would not be accurate. For this reason I chose glass marbles, very reflective surface and not subject to change.

As with the berries these images are basically SOOC with the only adjustments made being lens correction and white balance set to Flash. Once again they were resized in CC2020 using Save For Web.


f8.0, 1/200, ISO 100. Flash unit set to TTL. Metering Mode: Evaluative.

#1 Reference image, no diffusion.


#2 Using one of the diffusers made from skylight diffuser.


#3 Using the frosted diffuser material.


#4 Using the home made diffuser.


For me there is very little difference between any of the images. #4 with the home made diffuser is a tad under exposed most likely because of makeup of the diffuser, but the reflections are just as prominent.

#5 A composite of all the images.


Conclusion: It is my belief that the diffusers are not working because they are too close to the light source. It would not be practical to move the diffuser further away from the ring flash as that would make it very difficult to get up close for macro shots, which is what the ring flash is intended for. Looks like I'll have to practice up on my photoshop skills .

[Isac]

Tip for all who might use it:
Select the Spot Healing Brush Tool (J)
Use settings: Normal OR Replace / Type: Content Aware / Check Sample All Layers
Make a new layer above your subject layer. This will be used for the healing brush to work on so it can be adjusted if needed.
Adjust the brush tool diameter (using the Right and Left bracket keys), to make the circle cover the item to be removed.

With the new layer selected, and the circle around the part you want removed, click and it will be replaced with the surrounding pixels.

It will even try to find contrasting lines or in this case, the curve.