110 XL Soft Focussing

[JPlomley]

I had a chance to try out a 2005 manufactured 110XL recently and had considerable difficulty getting a sharp focus point on the GG of my Arca. I had no problems whatsoever with my 135 Sironar-S or 90/4.5 Grandagon-N against which I was testing this optic, on the identical subject. The focus play on the 110 was about 0.2 - 0.5 mm of spread, whereas with the Rodies, the focus point just "popped" with virtually no play. The resolution of the Rodies on the GG was also significantly better than the 110XL. Could there simply be an issue with this particular sample? Or is this typical of the Symmar design?

[Kevin Crisp]

I know that back when I could focus with just reading glasses (no loupe) the one lens I would make mistakes with was the 110. With a loupe I could easily see when it was in focus when wide open. You are comparing it to a longer lens (135) that would have a more shallow depth of field, and a bigger image at the same distance, and that might explain why it seems to pop in and out of focus for you more easily. You are also comparing it to a 90mm, which is a shorter lens but is also faster, which would give back some depth of field and give you a brighter image on the ground glass. Mine is plenty sharp for focusing wide open, unless there is some other explanation for this maybe you have a sample specific problem.

[Bruce Watson]

The focus play on the 110 was about 0.2 - 0.5 mm of spread, whereas with the Rodies, the focus point just "popped" with virtually no play. The resolution of the Rodies on the GG was also significantly better than the 110XL. Could there simply be an issue with this particular sample? Or is this typical of the Symmar design?

My sample of the 110mm SS-XL doesn't do that. Very easy to focus wide open. It has a definite "correct" focus point -- not a spread like you are finding.

Some of the 80mm SS-XL lenses were soft wide open. I don't remember the cause, but I'm thinking it was an element spacing problem. But my 80mm SS-XL doesn't have that problem either.

So I'm thinking it's a problem with your particular sample. It's very unlikely that it's a problem with the Super Symmar design; the Super Symmars have earned sterling reputations.

[JPlomley]

Cheers folks. Sounds like I would be better off getting another sample.

[Ron Marshall]

The sample I had was easy to focus and one of the sharpest lenses I owned.

[Dave_B]

The sample I had was easy to focus and one of the sharpest lenses I owned.

ditto

[JPlomley]

It is that measured performance by so many on this forum that has driven me to get a good copy. I ran out of IC in Zion last year too many times with my 135 Sironar-S, so I need the 110XL before I head to Sequioa in three weeks and Midwest is out of stock!

[Kevin Crisp]

If you focus at f:8 is this a problem? Is the finished product sharp?

[Rob Champagne]

It is that measured performance by so many on this forum that has driven me to get a good copy. I ran out of IC in Zion last year too many times with my 135 Sironar-S, so I need the 110XL before I head to Sequioa in three weeks and Midwest is out of stock!

Lens spacing on the 110XL is more crtical than on other symmars since it is not a true symmar. If you are having focus problems with that lens, then I suggest you first have it bench tested as all that may be required is an additional spacer ring. Mine came with two when it was new. If yours has none I suspect that may be the culprit.

[Glenn Thoreson]

Wide angle lenses are more difficult to determine when they are in sharp focus. That's their nature. Folks with very good eyesight may have no trouble focusing them. Folks with questionable eyesight, such as myself, can have various degrees of difficulty with them. That doesn't necessarilly mean the lens is faulty. I have several examples of lenses, some of which are a snap to focus, and some are very hard to focus. They all produce sharp negatives, though.