?: Using flash with HDR

[greyhoundrick]

Hello everyone,

Always great to be with you!

Im brand new to HDR photography and I also enjoy taking images with off camera flash. I wanted to combine the two and see what I can do, however, Im not exactly sure as to the best approach.

If I am shooting at sunset in the desert and want to add flash to say, a cactus, would it be best to use the flash on just one of the exposures and take the other bracketed shots without the flash? Or, rather take them all with flash and just bracket the ambient light?

In addition, I guess you can do the bracketing with all flash images as well.

What would be the best approach to this? Is it a situation where its just trial and error or do you think there is an ideal way to tackle this?

Thank you so much for your expertise and time. I always appreciate hearing from you!

best,

Rick

[Shadowman]

Hi Rick,

Best to do trial and error, think about what flash does to a scene and also the purpose of HDR to enable you to capture the dynamic range of a scene. What light source would you find in a desert scene at sunset, would it be in your frame or would you use the light source to expose the shape of the cactus?

[greyhoundrick]

Great points John. Thank you!

At sunset the ambient light is really starting to fade and the flash lights up the foreground. Here is a shot, though not HDR, that I did some years ago in the same general area. I used one bare Alien Bees 1600 and underexposed the sky a bit. Then hit it with some post processing in Photoshop.

https://www.flickr.com/photos/greyho...posted-public/

Sorry to post the link instead of the image. I need to figure this out ha ha.

Will give trial and error a shot and see what happens. I think I will try ambient bracketing and flash bracketing and see what I get.

Thanks again!

Rick

[Manfred M]

I rarely find the need to use HDRI any more. Modern cameras with their extremely high dynamic range (just over 14 eV on my old D800 at base ISO). The data is recorded and all I have to do is use PP to draw the data out of the raw file.

With respect to your aim of using off-camera flash to create an HDRI image, if it were me experiment to see what works out best for the final image. I assume that you would be using a fixed aperture, fixed ISO and varying the shutter speed to control the amount of ambient light hitting the sensor. If you use a single flash exposure, the shot with the off camera flash will have lighting that is significantly different than any exposures made without it, so blending these with HDRI software will probably give you a rather strange bit of lighting (it might be worth experimenting as the look might or might not be good).

I would suggest you vary the flash power output in proportion to the changes in exposure value (eV) for the ambient. As you are shooting studio lights, you have a lot of power to play with. The main concern I would have is the quality of the light. Even a very large softbox is still going to give you a fairly hard light, given the size of your subject and the distance you would be away from it. I don't shoot the Alien Bees, but have four Paul C Buff Einstein 640 lights, so I do have some feel for what you are up to.

I would also look at gelling the light. Getting a mix of daylight + golden hour light is going to give you a strange combination of mixed light. I normally would start with 1/4 cut of CTO (Color Temperature Orange), but you might need a 1/2 cut or even full cut at that time of day, especially as the sun gets closer to the horizon.

Good luck and I look forward to seeing what you come up with.

[greyhoundrick]

Thanks so much Manfred! Excellent advice! Will give it a shot!!

[inkista]

I would suggest you vary the flash power output in proportion to the changes in exposure value (eV) for the ambient. ...

At last! A use for FEB in this age of digital chimp-adjust-reshoot.

[greyhoundrick]

At last! A use for FEB in this age of digital chimp-adjust-reshoot.

[sharaff]

I've never come across any tutorial that suggest using flash for HDR photos (e.g. https://aurorahdr.com/how-to-shoot-hdr). @GrumpyDiver has a point, lighting might be rather strange. But since it's your idea you have to try. I'm curious about the results