Michael R
9-Aug-2016, 07:02
Yes, I searched old threads first, but found no definitive conclusions.
A friend exiting LF gave me his Rodenstock 4x Magnifier. It seems to be brighter than my old cheapo loupe so I'd like to use it. Some questions:
1) The instructions for "focusing" read as follows: "To focus, keep the magnifier steady in front of the eye and turn the focusing ring until optimal sharpness is achieved. This process will also correct sight defects up to -2.5 dptr."
I'm confused. Is it focusing or adjusting the diopter correction? Isn't it one or the other? Since I wear glasses, I wouldn't use diopter correction. I would have thought a "focusable" loupe would need a separate ring for focusing.
2) Is the whole "focus" thing a red herring when it comes to loupes and ground glass viewing? You frequently read people saying to make sure the loupe is focused on the ground side of the ground glass to avoid focus error, but isn't the image we see through the loupe formed on the ground side anyway? Even if the loupe is "focused" on the near side of the ground glass, we're still seeing the image formed on the ground side, right? Maybe it won't be quite as crisp, but when focusing the camera "best" would still be "best" (for lack of a better phrase). It's not like an out-of-focus loupe would cause you to focus on some "alternate" image leading to out of focus negatives.
A friend exiting LF gave me his Rodenstock 4x Magnifier. It seems to be brighter than my old cheapo loupe so I'd like to use it. Some questions:
1) The instructions for "focusing" read as follows: "To focus, keep the magnifier steady in front of the eye and turn the focusing ring until optimal sharpness is achieved. This process will also correct sight defects up to -2.5 dptr."
I'm confused. Is it focusing or adjusting the diopter correction? Isn't it one or the other? Since I wear glasses, I wouldn't use diopter correction. I would have thought a "focusable" loupe would need a separate ring for focusing.
2) Is the whole "focus" thing a red herring when it comes to loupes and ground glass viewing? You frequently read people saying to make sure the loupe is focused on the ground side of the ground glass to avoid focus error, but isn't the image we see through the loupe formed on the ground side anyway? Even if the loupe is "focused" on the near side of the ground glass, we're still seeing the image formed on the ground side, right? Maybe it won't be quite as crisp, but when focusing the camera "best" would still be "best" (for lack of a better phrase). It's not like an out-of-focus loupe would cause you to focus on some "alternate" image leading to out of focus negatives.