Hi everyone! I am having trouble with my indoor pics of geckos. I'm a reptile breeder of crested and gargoyle geckos which range from the size of your pinky finger to the full length of your hand. Capturing their colors and being in focus is key in the hobby. Normally, I can take pretty decent outdoor pictures because of all the natural light. I am trying to take photos with a light tent and a sunny window from the side. Not enough of the geckos are in focus and the colors don't show as vivid.
I need tips/help/all the things. I'm using a Nikon D3100 with the stock 18-55. Not sure if I should get another more useful lens or what. Or just guidance into settings :)