My foam diffusers taped directly to the heads are not diffusing the light enough.
Now I am trying to make new better diffusers.
What I know. Or at least I think I know is:
1. The diffuser are shall be larger than the flash head. (Mine is not at the moment).
2. To keep the flash duration as short as possible the diffuser shall not be too thick and the distance from the diffuser to the subject shall be as short as possible.
3. A thick diffuser will make the flash duration longer and this makes the risk of glare higher.
Please provide any info you have based upon experience. Please also post pics of your diffusers.
Do not agree fully with #2 & certainly not #3. The thicker the diffuser the less risk of blown glare on the subject but yes the flash duration will be longer. Obviously there is a difference between simply blocking light and diffusing it but having tested quite a few diffusing materials, I always seem to end up with something that loses 2 stops of light compared to no diffusion. You can check this by using the flash in manual and finding where you get equivalent exposure.
Be aware though that there is a delicate balance between diffusion and detail showing - the more diffusion, the less fine detail will show.
You just need to strike a balance that gives you the shots you want.
My only requirement on flash duration is to be able to shoot around 4 or 5 shots without the flash recycling and that is only because often I need to take a fast sequence shots for focus stacking.
Thank you for your valuable input. I have an arm for one of the flashes. I am thinking about making a fill flash with a larger diffuser on top and a smaller for the direct flash.
The problem with the MT-24EX Anden is that the actual flash tubes are not that much larger than the one in your camera's built in flash -very small, very harsh light source. Brian can afford to lose two stops because he's using a standard camera flash -but you can't. Try to find a way to diffuse the MT-24EX so that you are losing no more than one stop compared to an un-diffused flash.
As for your points:
1) You need to make the diffuser bigger than the flash head -you can only get the MT-24Ex's heads so close and they are just too small.
2) True -diffuser thickness and distance to subject will effect flash duration, and also your ability to produce diffused light.
3) I have found this one to be true -the longer the flash has to turn on the more time reflective surfaces have to bounce photons back into the lens. Longer flash durations also seem to adversely effect the red channel in the histogram (easier to blow it out).
Now I'll add some additions:
4) The material that you use to diffuse the light can and will effect the quality of it -and not just the temperature. Some materials pass certain parts of the light spectrum better than others, so just because you can use something to diffuse the flash doesn't necessarily mean that you should. If you don't want to spend money on diffusion plastics that are designed for photographic use then you'll need to experiment to find something that will give you the light quality that you want for your photos.
5) The flash mount that comes with the MT-24EX is just about the best thing that you can use for the MT-24EX. I spent a lot of money experimenting with getting more distance between the flash heads only to watch the quality of the light suffer for it. For 2x and higher shooting push the flash heads so that they are pointing all the way down toward the lens. For 1x bring the flash heads "one click up".
6) Ratio control just makes one flash head more brutally harsh than the other, so just turn it off. As long as you do not place the flash heads 180 degrees apart the light won't look flat.
7) I use a Kaiser adjustable flash shoe to change the angle of one flash head relative to the subject, so that I don't have both flash heads hitting the subject at the same relative angle (reduces glare). Details at my blog. Also allows me to get a lot of detail in a critter's compound eye -the lenses look convex and not just flat reflection points. Click on the image on this page for a 1600 pixel wide version and take a close look at the eyes on that bee. Here's a smaller version:
I'll add more as it comes to me. The MT-24EX is a very difficult flash to tame, but if you can get good light out of it then you can use just about any flash...
Brian can afford to lose two stops because he's using a standard camera flash -but you can't. - I thought Brian also uses the MT24-EX?
Now I'll add some additions:
4) The material that you use to diffuse the light can and will effect the quality of it -and not just the temperature. Some materials pass certain parts of the light spectrum better than others, so just because you can use something to diffuse the flash doesn't necessarily mean that you should. If you don't want to spend money on diffusion plastics that are designed for photographic use then you'll need to experiment to find something that will give you the light quality that you want for your photos.
Anden says: I think that the foam plastic I use works pretty good. I will look into new options for referenc though. THe reason I am building my own is that I like to experiment and also from the various reports here that the ones built for the flash are not very good.
5) The flash mount that comes with the MT-24EX is just about the best thing that you can use for the MT-24EX. I spent a lot of money experimenting with getting more distance between the flash heads only to watch the quality of the light suffer for it. For 2x and higher shooting push the flash heads so that they are pointing all the way down toward the lens. For 1x bring the flash heads "one click up".
Anden says: That is what I am doing too. I have read your tutorials many times.
6) Ratio control just makes one flash head more brutally harsh than the other, so just turn it off. As long as you do not place the flash heads 180 degrees apart the light won't look flat.
Anden says: I have not even tried the ratio yet. Thanks to you :-)
7) I use a Kaiser adjustable flash shoe to change the angle of one flash head relative to the subject, so that I don't have both flash heads hitting the subject at the same relative angle (reduces glare). Details at my blog. Also allows me to get a lot of detail in a critter's compound eye -the lenses look convex and not just flat reflection points. Click on the image on this page for a 1600 pixel wide version and take a close look at the eyes on that bee. Here's a smaller version:
Anden says: That is why I go the flash shoe for my setup. Do you use the same diffusers for both heads?
I have a pair of Sto-Fens that I cut the front out of (so I could use them as a frame) and hot glued a pair of Puffer diffusers over them. The stock Sto-Fen will work, but IMHO it's still too small of a diffusion surface.
Dalantech wrote:
I have a pair of Sto-Fens that I cut the front out of (so I could use them as a frame) and hot glued a pair of Puffer diffusers over them. The stock Sto-Fen will work, but IMHO it's still too small of a diffusion surface.
I have looked at the sto-fens but I didnīt buy them for that reason. Great suggestion to combine them with puffers. How far do they protrude?
The easiest way to answer both of you was to take some pics with my iPhone, email them to myself, and then push them to Flickr
The details: I cut the front out of a set of Sto-Fens to use as a frame that I hot glued a set of Garry Fong Puffer diffusers to. Also I used a metallic insert from a Lumiquest Big Bounce to fill in some of the gaps (easy to cut).
I didn't understand your comment, unless you're talking about the metering mode. It really depends on the scene n0b0 -IMHO no one mode is going to work well for every situation unless the flash is set to manual...
What I meant was that the highlight isn't gonna be very even with the center being brighter because of the more concentrated light there from the flash. Here's an example, look at the round highlight, the center part is slightly brighter. http://farm4.static.flickr.com/3391/3482854995_0f608f6a65_o.jpg
Since you can't make the area around the center brighter, you'll have to lose some more light in the center to make the highlight more even. That's what I meant.
What I meant was that the highlight isn't gonna be very even with the center being brighter because of the more concentrated light there from the flash.
I think I'm eliminating that problem with the Puffers, since they are curved...
