problem with xenar 150mm

[visionarte]

hi everyone. this is my first time in this forum, i just bought a second hand toyo view with couple of lenses (90mm super angulon f:8 and 150mm f:4.5). i had used only few times in the past a lf camera and always wanted one so finally i got one. anyhow trying if everything works alright with the set purchased i found that there is no way that i can focus with the 150mm lens. in the glass everything looks blur ( like in a enlarger when the ring adaptor is put on in the wrong way around, it starts out of focus and it goes worst). with the wide angule everything is perfect and i don't understand what is going on. the lens seems in perfect condition tough. i would appreciate if somebody has idea of what's the problem. i hope is something that i do wrong, so i don't want to give back the camera that i just bought. schneider 150mm compur is the lens.

please some help

[Gem Singer]

You might have the front and rear standards too close to each other when starting out.

Try doing a rough focus by sliding the front and rear apart until the image begins to come into focus on the ground glass.

Then, obtain fine focus using the focusing knobs.

Should be no problem focusing a 150 with that camera.

[visionarte]

hi gem, the problem is that nothing is near to be in focus even sliding standars from far to close. closing the aperture to 22 and being very close (as for wide angule more or less) is the only way of recognise shapes, but imposible to focus o refine. i don't get it. the few times i work with this camera was with a 150mm lens and never had this problem.

[Gem Singer]

You stated that there is no problem focusing the 90.

Therefore, since you cannot get the 150 Xenar to focus at any distance, there probably is something wrong with the lens.

Check to make sure the front and rear elements are screwed into the shutter properly.

[Andrew]

maybe someone slipped on the wrong rear element by mistake?

[IanG]

It sounds like the front standard is in the wrong position on the focus rail, you need to move it substantially forward compared to the 90mm, approx 4 inches, for infinity focus.

Ian

[Vick Vickery]

Welcome to group therepy! Since you have no problem focusing the 90mm, which is normally a harder lens to focus than a normal lens, and assumming (dangerous!! ) that you are pulling the front standard out a little less than 6" from the ground-glass to start, there almost has to be a problem with that lens. Just to be sure, take a tape or a ruler and set the center of the front standard at 5.0" ahead of your ground glass (measure from the front of the glass to the center of the standare from the INSIDE with your lensboard removed to make sure) then put on the lensboard with the 150mm lens on it. From this position you should get to a sharp infinity focus by moving the lens forward only...go slowly and see if it doesn't come into focus with less than and inch or so forward movement. If it doesn't, I'd have an expert look over the lens to make sure the elements match and are correctly spaced. Good luck!

[aduncanson]

This sounds like the behavior of a Xenar missing its rear cell. Have you got all the pieces together? There should be two elements cemented together behind the aperture.

[IanG]

This sounds like the behavior of a Xenar missing its rear cell. Have you got all the pieces together? There should be two elements cemented together behind the aperture.

One would hope you're wrong there should be a lens cell that screws in behind the aperture ,on the rear of the shutter, this contains the cemented cells

Ian

[visionarte]

i think is what andrew have mentioned, that the rear element of the lens has been swaped by mistake for a diferent lenght one, but i can not be sure. I tried everything and something is wrong. this is driving me crazy