buckscop Loc: Bucks County PA

Hoggers. Hobbyist here. Newish owner of a Canon R7. As a favor, today I am taking pictures of a family on the beach. I had a Canon T7i, that had a built in flash that i could set to use for fill-in flash. The R7 does not have a flash, so i purchased a Speedlite 270exii. The pics will be shot in the mid-afternoon, with most likely the sun to their back causing shadows. I want to shoot some of the pics on Av as to get the background blurry, and have the fill-in flash because of the sun position. I cannot find a way for the flash to fire on Av (without it being dark). If i set it to the 'portrait' or 'group' mode, it will fire, but not on Av. Can anyone with a 'R' unit help. I searched both manuals and cannot find a clear cut 'do this' for a fill-in flash situation.

Thanks in advance for any help.

BobPeterson Loc: Massachusetts

From the Canon web site about flash in Av.
"If you set a very wide aperture on a bright day, the camera might not be able to select a shutter speed fast enough for correct daylight exposure. The result will be an overexposed image. You can avoid this by checking the shutter speed value displayed in the viewfinder before shooting. If the value is flashing, it means you are out of range and should set a smaller aperture."
If the camera thinks the scene will be overexposed then it won't fire the flash. Maybe spot metering will help??

gvarner Loc: Central Oregon Coast

Use Manual mode on your camera, expose for the ambient light. Use flash EC to get the fill that you want. You can also underexpose the ambient light. Remember that when using flash there are two light sources, ambient and flash on the subject and you have to expose for each.

PHRubin Loc: Nashville TN USA

I have the R7 and use manual after a test shot to determine fine setting adjustments.

williejoha

Use manual mode and adjust your flash output accordingly.
WJH

Architect1776 Loc: In my mind

stan0301 Loc: Colorado

Disney, who must have researched it up one side and down the other mostly sets the flash to minus two - but - never photograph direct sunlight on the face

IHH61 Loc: Homestead Fl

Try setting your flash to High Speed Sync. Then use both EC and FEC to get the right balance

Hugh

amfoto1 Loc: San Jose, Calif. USA

The problem is that your large lens aperture is forcing the camera to use too fast a shutter speed, which is faster than the flash sync speed (1/250) and therefore the flash won't fire.

I don't know if it's possible with the 270EXII in particular, but with the 400EX, 500EX and 600EX series flashes you can set "high speed sync" (HSS) that allows you to use the flash with shutter speeds faster than the camera's sync speed.

HSS does reduce the distance that the flash can reach, but you are shooting portraits and that means you won't be very far from your subjects, so I imagine this won't be a problem.

Assuming you are using ETTL or ETTL II with the flash (i.e., not using "manual" flash), Canon cameras and flashes automatically go into "fill flash" mode whenever you use any of the camera's auto exposure modes like Av (also Tv and P... and probably M + Auto ISO). This means the flash will fire with reduced power. Typically it's -1.66 stops.

Again, I don't know about the 270EXII, but the bigger flashes allow you to dial in "flash exposure compensation" (FEC) to adjust the amount of fill flash. (Note: It is also possible to dial "full" flash up or down with FEC... With ETTL/ETTL II "full" flash is the default only when the camera is set to M manual exposure mode.)

I don't have an R7 (yet) but many of the newer Canon cameras have means of controlling the flash's settings via the camera's menu. If there is no way to enable HSS on the 270EX II, you may be able to set it in the camera's menu.

And, yes, Exposure Compensation (EC) can be used to tweak the camera's auto exposure, if wanted. This is separate from the FEC mentioned above.

Another solution, if the flash doesn't offer HSS, is to use a neutral density filter on your lens to slow the shutter speed down to 1/250 or longer. Take a meter reading with the camera set to M, the lowest ISO 100, the aperture you want to use and 1/250 shutter speed. Observe how many stops of overexposure the camera's meter is indicating with those settings, then use an Neutral Density filter that's at least that strong. It will be okay fine if it's one or two stops more, but try not to go too far and cause the shutter speed to be too slow to freeze subject movement (a lens with IS or the camera's IBIS will correct for any handheld camera shake at slow shutter speeds, but can't help at all if your subjects move).

If you go the ND filter route, you may have trouble seeing your subjects in the viewfinder to compose. Turning on "Exposure Simulation" can help with that by brightening up the viewfinder.

Do not set your camera to a "scene mode" such as "Portrait". That will override your settings with some programmer's idea of how a camera should be set to take a portrait, rather than the settings you want.

Both the "back lit" portraits below were shot with camera in Av mode, flash set to ETTL and HSS... one was at 1/320 shutter speed, the other at 1/500 (I forget what that camera's sync was.... 1/200 or 1/250 I'm sure)... my focal length was around 160mm (70-200mm lens) because I was being careful to not use flash too close to the horses. No FEC was used, so the fill flash was around -1.66 stops... just enough to open up shadows and add catch lights to eyes. The camera EC for the left hand, more side lit image was -1/3 stop and -2/3 stop for the right hand, more back lit image: