Help with my lens!

[Keytarjunkie]

Hi, So far I haven't bought a decent lens for my mediocre japanese wood 4x5 camera I just got. I found two lenses in a drawer so I decided to just use those until I could afford anything (college student!). One is an old 90/8 Graflex Optar in a Graphex shutter...it's the first one I tested out and it's terrible! Not even worth keeping!

The second lens is a Caltar II-E 150mm f/6.3 (multicoated). However, I don't think it is actually a 150mm at all. When I mount it onto my camera, the front standard reaches infinity only a few mm's farther than my 90mm, and based on my eye, it looks to be acting more like a 100mm or 110mm on the ground glass. I also have a 127mm lens attached to my 4x5 rangefinder which I don't want to take off for fear of it becoming uncalibrated. However, based on how extended that lens is at infinity, it looks like it's much farther away from the film plane than the "150mm"! I have used a 150mm in the past and it is much more like a "classic 50mm" whereas this Caltar seems to be acting as a wide angle lens. So I guess I'm asking if it is possible that the rear element of this lens was switched with another one at some point in time, and how bad this would be optically. Honestly the ground glass looks fine to me but I have no idea if it will show up any better or worse in print...I guess I will try it out today but I was hoping to get some feedback on it here, where you people are so knowledgeable about everything and I'm just a newbie...thanks a bunch!

[Jim Noel]

It would not be a surprise if some time in the past the rear element of the 150 was switched. The 150 Caltar II-E is a very good lens when unaltered.
I am surprised that the 90 Optar is so bad you are considering throwing it away. While certainly not the best 90 ever made, it should be at least serviceable unles it also has been altered.

Make an exposure or two with each of the lenses before you make a final evaluation.

[Robert Oliver]

have you measured the lens to film plane distance with your 150? 127?

[Keytarjunkie]

I don't have a ruler, otherwise I would...but I put my ground glass on the rangefinder just because I can't judge by the framelines, and the 127mm is MUCH longer in focal length than the 150mm. The 127mm is definitely optically correct and acts as a 127mm should, in my experience.

Please bear with this very unscientific test. I held up my real 4x5 w/150mm and rangefinder with 127mm at my window from the same distance and photographed the GG.





As you can see, the 127mm image looks much more cropped (but they are both 4x5, rest assured). This is both lenses focused at infinity, with the film planes of both cameras in roughly the same plane...the 150mm looks way farther back than it should be, yeah?