focusing loupe vs magnifier loupe?

[francesco_bertelli2]

<p>there is any valuable, substantial, difference between a fousing loupe and a magnifier for negatives?<br>

just asking because I want to change mine, Im using a old loupe for slides as a focusing, but I dont want to buy two of them but just one, a good one...</p>

[bob_salomon]

<p>The best way to focus sharply is to have the magnifier adjusted so that it is focusing on the grain side of the gg where the image will be formed. To do this simply you just take the lens off the camera, point the camera at a light source and focus the eyepiece of the magnifier until you see the grain of the gg in sharp focus. Then you are in focus at the actual image plane.<br>

Most non-adjustable magnifiers will be in focus on the back side of the gg, not the grain side. So when you focus sharply with that type of magnifier you will actually be out of focus by the distance from the side the magnifier is resting on to the grain side of the gg.<br>

Same when using a magnifier for viewing film. If you can not ajust it to be in sharp focus on the grain side then you are not actually seeing how sharp, or unsharp, the image really is. Good loupes/magnifiers have adjustable eyepieces to focus on the actual surface that the image is formed on.<br>

And we do import and sell both types to our dealers so we really don't care which type you use.</p>

[francesco_bertelli2]

<p>wow, that's an interesting explanation! i never thought about ti...thanks!!! i'll try it tonight!</p>

[ian_gordon_bilson]

<p>A loupe that cannot be adjusted for focus is pretty much useless for any practical application to do with a view camera.</p>

[rodeo_joe1]

<p>The main difference is that a focusing magnifier is set in a solid opaque tube, whereas most general-purpose loupes have a transparent section to let light in on whatever is being magnified. You obviously don't want too much stray light falling on the focusing screen. Other differences are that a focus magnifier is sometimes a bit longer than a loupe so that you can use it more comfortably while it's resting on the GG screen. Also some focusing magnifiers have a focus-adjustment locking ring so that they're always set at the correct distance from the screen for your eyesight. Loupes have a focusing adjustment but usually have no way of locking it in place.</p>

<p>Apart from these subtle differences the two things perform almost exactly the same and there's no reason why a loupe can't be used for focusing as long as its adjustment will allow for the thickness of the GG (and rear Fresnel if fitted).</p><div></div>

[francesco_bertelli2]

<p>yesterday I bought a Silvestri 6x loupe with tilting base, and honestly i can't see a real value of that compared to an older Horizon 4x made in russia. Actually there are more cons than pro, first off you can rotate smoothly but I feel the best focus is always when i rotate all the way down...who's gonna use all the way up? or am i mis-using it?</p>

<p>when i rotate all the way down the loupe is so short than is quite uncofortable...I'm really disappointed overall considering that I paid it 90 bucks... I know the scheiner 4x is 150$..but at least is way bigger and eaier to use...am i right?</p>

[francesco_bertelli2]

<p>@<a href="../photodb/user?user_id=47422">Bob Salomon</a> i dont get waht you mean by grain side, given that my GG has the grain on the back side...what kind of gg are you taling about?</p>

<p>also i have another camera with a fresnel and a back plastic glass that has no grain...so your example cant be applied right?</p>

[bob_salomon]

<p>Most cameras that are properly set up have the grain side facing the lens. Otherwise the focus plane can be off by the thickness of the gg and, possibly, the Fresnel screen, if it is under the gg.<br /> There are some screens, the long discontinued Linhof Super Screen was one, that combined a focusing surface with a Fresnel screen. That type of screen was properly installed if the grooves of the Fresnel side faced the eye.<br /> Another type of screen was the Boss screen that was made from two pieces of glass with a parrafin layer between them that became the focus plane. To use that type of gg you had to have one made for your camera so the wax layer was at the correct point.<br /> Was your gg installed by the factory that way or was it replaced by someone at some time?<br>

If your magnifier has good correction ability like the Rodenstock 4x and 6x aspherics then they can focus on the grain when a cover plate is on top of the gg. So can the Wista loupes.<br>

<br /> Joe,<br /> Good loupes, like the Rodenstocks have either reversible skirts or sliding skirts so you can use them with prints or on a gg. Others from Wista and Schneider also have the ability of using opaque or translucent skirts. Just the Rodenstocks don't require an extra part to keep track of when you change from viewing a gg to viewing a slide or print or leaf.</p>