Your shutter speed, and iso will effect The ambient light, or constant light exposure, aperture, will too when just using constant,ambient, available light. The aperture and iso will effect the flash exposure, (if your using a flash) and depth of field.

If you want more of the picture in focus you need a smaller aperture. f8,f11,f16. But using a small aperture will slow your shutter speed down. Ok so to get your shutter speed up. The only thing left to do is raise your iso. When you go up on your iso. You get more noise in your image. ISO is how sensitive your sensor is to light.

Your 18-55mm and 55-250 mm lens. Im pretty sure have a variable aperture. I think your 18 to 55 is a 3.5 to 5.6 or something like that. So that means your widest aperture you can get on that lens is 3.5. But thats only at 18mm. If you set your lens at 18mm, and aperture of 3.5 or whatever the widest is . Then you zoom to 55mm. Your aperture changes. You widest aperture at 55 is 5.6. So if your zooming in and out. Your aperture can be changing. That will effect your exposure. If you think your shooting at 3.5, but you zoom in to 55mm. Your now at 5.6. but your shutter speed is still set for a good exposure at 3.5. Same with the 55-200. Thats if your shooting in manual mode. If your in aperture priority or an auto mode. The shutter speed will change with it, to get what the camera things the proper exposure is.

Slow shutter speed you will get blur from camera moving, and your subject moving. Id say start off with at least a 1/125th for your shutter speed, to freeze motion. Faster the subject moves, the faster shutter speed you may need. If your shooting your 55-200 at 200. (a good rule of thumb) Your shutter speed should = or + your focal length. That will help cut down the camera shake,if hand holding your camera. So shooting at 200mm then your shutter speed, can be set at 1/200th or faster, to help with camera shake.

Use a smaller aperture to get more of the subject in focus. f/8, f/11, f/16. Again using a smaller aperture, you are letting less light in. So you need to compensate for that somewhere else. Shutter speed, or ISO. Aperture effects the amount of light coming into your sensor. Shutter speed effects the duration of light. (How long the light hits the sensor.)

So faster shutter to freeze your subject, smaller aperture, to get more in focus, Bump up your ISO up. Be careful with the ISO. It will add noise to the image the higher it goes. If your still not getting a proper exposure, then you may need more light..

I used constant light for a long time. Flash really freaked me out.. Now that I have started shooting with flash, I will most likely never go back to constant lights. I still shoot a lot of available light stuff. Id check into getting one of these flashes, and radio triggers, Just make sure they will work with your camera first. That way you can get the flash off camera. These are not top of the line, triggers, or flashes. But they are great for what they cost. A great low cost way to get into off camera flash..

http://www.amazon.com/Yongnuo-YN-560...2995965&sr=8-1

http://www.amazon.com/Yongnuo-Wirele...ref=pd_sim_p_7

I took these pictures with a single flash, A nikon sb600, in a westcott 28in softbox. With the yongnuo flash triggers. The softbox was placed over the top of my old Rubbermaid tub light box. I was shooting at 1/125th at f/8 to f/11, Iso 100/200


Female 1 Second one out by SDReptiles, on Flickr


20120322-SDA_3311 by SDReptiles, on Flickr


20120322-SDA_3302 by SDReptiles, on Flickr


20120322-SDA_3300 by SDReptiles, on Flickr

They are not the greatest images. The setup still needs a bit of tweaking. The background is just black poster board. But its a start, and just a single small nikon sb600 flash. Pointed down from the top. I hope this didnt confuse you more. I kind of bounced around a bit.

A few more things. I was shooting at a somewhat small aperture. And not the whole snake is in focus, in some of the photos. That had to do with my lens. I was zoomed all the way out to 50mm, and I was maybe a foot away from the subject. So it gave me a more shallow depth of field. If I would have zoomed out to 17mm, the widest that lens would go. Pretty much everything would have been in focus. But I would have had some distortion from the wide angle lens.

Camera used is the Nikon d7000. With the Sigma 17-50mm f/2.8 OS lens. A single sb600 flash, 28 inch softbox. Thats pretty much it.