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<blockquote data-quote="J-see" data-source="post: 454605" data-attributes="member: 31330">I don't really understand the question Bill. My DOF depends upon the magnification/aperture combination. Anything I add to the lens, like the close-up or extension tube, only indirectly affects my DOF since it affects the minimum and maximum focus distance of my lens. It's because I have to get closer to focus, or can get closer, my magnification changes and that's what has an effect on my DoF.Adding diopter to my lens makes it just as hard to focus as any other. I have more working distance and thus can add a bit more before I start squeezing my subject but it doesn't make it easier to find focus.Here's a table to check your focus distance according the diopter you have:[ATTACH]158132[/ATTACH]If you know the focus distance of your lens and add the 4.8 or 8 of the Raynox, you know where your focus is situated.My lens focuses from infinity to 50cm which is from 0 to 2D. If I add 4 diopter, the focus shifts from 4D to 6D which implies I lose infinity and can only focus between 25cm and somewhere around 17cm. My focus range from max to minimum suddenly is only 7-8 cm which explains why it becomes so hard to focus on the subject.</blockquote>

[QUOTE="J-see, post: 454605, member: 31330"] I don't really understand the question Bill. My DOF depends upon the magnification/aperture combination. Anything I add to the lens, like the close-up or extension tube, only indirectly affects my DOF since it affects the minimum and maximum focus distance of my lens. It's because I have to get closer to focus, or can get closer, my magnification changes and that's what has an effect on my DoF. Adding diopter to my lens makes it just as hard to focus as any other. I have more working distance and thus can add a bit more before I start squeezing my subject but it doesn't make it easier to find focus. Here's a table to check your focus distance according the diopter you have: [ATTACH=CONFIG]158132._xfImport[/ATTACH] If you know the focus distance of your lens and add the 4.8 or 8 of the Raynox, you know where your focus is situated. My lens focuses from infinity to 50cm which is from 0 to 2D. If I add 4 diopter, the focus shifts from 4D to 6D which implies I lose infinity and can only focus between 25cm and somewhere around 17cm. My focus range from max to minimum suddenly is only 7-8 cm which explains why it becomes so hard to focus on the subject. [/QUOTE]

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