Cobra 440AF

[chorleyjeff]

This flash works fine on my 700si but will it work properly without harming my Alpha 100?
I'm going to Lancaster butterfly house tomorrow and the weather forecast is for the rain to continue so the light levels are likely to be low. I should like to take my non flash RAW pictures using a high ISO setting - say 800 ( tripods not allowed). Would this be OK for good quality A4 sized pictures?
Cheers
Jeff

[David Kilpatrick]

Use 400 for natural light not 800, there's a quantum leap in quality between the two.

Use ISO 100 for flash. The flash will only fire on full power, but this is not a disaster. You need to be working at f11 to f16 for butterflies. Even with the larger ones, f8 gives too little depth of field. Do not use f22 or f32, you will destroy the fine detail sharpness no matter what lens you are using. The best bet is a longer lens rather than shorter - 100mm macro, or a 70-300mm, or 70-210mm.

Wrap the head of the flash in a white handkerchief, and do some tests to find out how many layers you need. Another old trick is to tape the lid of an old Kodachrome or similar 'semi-opaque' white slide box over the flash head. Aim to get f16 at minimum focus distance. You will need extra batteries, and you will have to wait for the flash to recycle. Just do tests at home tonight.

The Cobra does not, I think, have manual fractional power but if it does, then use that (if the camera permits). It can not harm the A100 but it won't function fully. Use manual exposure on the camera.

David

[chorleyjeff]

Thanks very much for the advice.
But I read it too late for the visit so used the on camera flash but mostly no flash.
Results mixed. Depth of field was a big problem!
Will go back with the benefit of the advice.
Cheers
Jeff