Photoshop lý tưởng muốn ba lần so với RAM như là kích thước của hình ảnh bạn đang chỉnh sửa. Khi bạn sử dụng một ổ đĩa (hoặc phân vùng) nó có thể bị phân mảnh, có nghĩa là, nội dung của nó có thể được lan truyền trên tất cả các ổ đĩa. | Chapter 9 Shooting Digital Video 199 . Focusing a Canon XL1 Some DVcamera lenses notably the zoom lens that comes with the Canon XL1 . do not hold focus if you use the manual zoom ring on the lens to recompose your shot. Instead use the mechanical zoom button on the lens. You can also focus by composing your shot first and then adjusting the focus ring on the lens the same way you would with a prime lens. The only problem with this method is that the wider your shot the harder it will be to tell if your subject is truly in focus. You can also center your subject press the autofocus button until it finds the right focus then turn off the autofocus feature to lock the focus in place. Then recompose your shot as desired. The XL1 has a Find Focus button that allows you to set the focus without using the auto-focus features. Measuring Focus If your camera lens has a focus ring with distance measurements marked on it like the lens in Figure you can measure the distance between your subject and the lens to ensure perfect focus. Of course you can t be sure of the focus markings on your lens unless you ve tested them and found the marks to be accurate. If you plan to eventually transfer your video image to film proper focus is critical. When the image is projected and blown up to 25 times its normal size what looked in focus on a small video monitor may appear out of focus. Luckily most images have a depth of field that exceeds the depth of focus. In Figure the depth of focus is eight feet from the camera but the depth of field the part of the image that appears in focus starts a couple feet in front of the subject and extends to infinity. The woman seated behind the subject will appear in focus even though she s not on the plane of focus. If you re having trouble focusing use your manual iris control to iris down go to a higher f-stop number . This will increase your depth of field and improve your chances of shooting focused. If you re shooting in a low light .
