Courtroom video presentations can range from images on small screens installed in the jury box to images on courtroom video monitors or projection screens. Does video image size affect jurors' perceptions of information presented during trials? To investigate this we manipulated video image size as well as defendant emotion level presented during testimony (low, moderate), the defendant–victim relationship (spouses, strangers), and the strength of the evidence (weak, strong). Participants (N = 263) read a case and trial summary, watched video of defendant testimony, and then answered a questionnaire. Larger screens generally accentuated what was presented (e.g., made stronger evidence seem stronger and weaker evidence seem weaker), acting mainly upon trial outcome variables (e.g., verdict). Non‐trial outcomes (e.g., defendant credibility) were generally affected by defendant emotion level and the defendant–victim relationship. Researchers and attorneys presenting video images need to recognize that respondents may evaluate videotaped trial evidence differently as a function of how video evidence is presented. Copyright © 2014 John Wiley & Sons, Ltd.