If photography is a priority, the optimal times are within 90 minutes after sunrise and before sunset, when the sunlight is at its golden best.
If possible, fly with the door off, which is ideal for aerial photography since it eliminates reflections and distortions caused by the perspex canopy, but be careful not to poke your lens or anything else beyond where the door would normally be, the wind is ferocious.
For the same reason, keep your camera well tethered and don’t leave other equipment or lenses lying loose.
If you’re using an SLR camera, the ideal lens is a zoom with a focal length of around 24-70mm, regardless of whether it’s a DX or FX-format sensor.
Focus the lens at infinity, but aperture is less critical than shutter speed.
On a quality lens you should get crisp images just a couple of f-stops down from wide open, and you want at least 1/1000 second for sharp shots.
If necessary, adjust the ISO until you can achieve this.
Be careful if you’re using a wide-angle lens because it’s easy to get the helicopter rotor in the frame without realising, and at 1/1000 second the blade will create a black blur on your image.
Don’t rest your hands or arms on any surface since they’ll transmit vibrations.
If you do have a door in the way, keep the front of your lens away from the perspex, it might leave scratches.
Also you’ll annoy the pilot and that’s never a good idea.