---

Sorry for the bad photo:(. Is it possible to tell the species?

location: Barcelos, Portugal
date: 08/03/2008

---

Meigenia ?

---

Thank you for your suggestion Stephane:)

---

This is hardly a suggestion, seems 100 % correct.


Theo

---

Thank you Theo, for confirming the excellent "sugestion" of Stephane;)

---

Not that bad a photo. The image is sharp and full of detail, but dark. Can readily be brightened in something like Photoshop.
What happens is that cameras try to make every image having a brightness of a neutral grey; usually an 18% reflectance.
Thus when you have a lot of white in an image, the camera typically underexposes to make the white more like a grey. If you have a dark fly on a white background the fly will be very underexposed - as in your image.
If you have a dark fly on a dark background the camera will overexpose both the background and the fly to get everything grey with everything overexposed.
The solution: If lots of white in a subject adjust the EV (exposure value) on your camera to +1 or even +2.
If lots of blacks on your image, and you want to keep the blacks as black, then adjust the EV to -1.
If lots of green in your image leave the EV at 0; plants give an 18% reflectance.

---

Thanks a lot Tony, I really am needing those tips:)

I'll try to do what you explained me, and I'm anxious to give it a shot.;)

---

First class tip by Tony


Theo

---

In the studio/lab, it is better to set the white balance, which also adjusts for colour cast. In the field you usually don't have the opportunity/time to do this. To be honest, I usually fix this sort of thing from a field shot in Photoshop - but that's probably because I am a lazy point and shooter and Tony is a zillion times better photographer than me.;)

---

yeah, Tony is right.

I use those tips all the time. :)
And a good diffuser is important so the light can spread much better and don't concentrate just in one part of the object.

---

White Balance and Expoposure Values are not the same.

In this image WB looks OK; the blacks on the 1st abdominal seg. and the 1st femur are pure (i.e., equal values of R, B, G) - no colour cast. The wall is a tad too green but this is probably correct as it will reflect some green from nearby foliage. Usually just leaving the WB at A works well for outdoor shots.

This photo is underexposed (to us) but perfectly exposed from the camera's point of view (actually for the person who programmed it at manufacture). The camera should have a button "+/-"; pressing this button and turning a control wheel either clockwise or anticlockwise will change the EV values in 1/3 or 1/2 values. Plus values make the image brighter, minus values make it darker. This is what needs to be adjusted in the field (or in the studio).