New Member Registered: June, 2017 Posts: 15 | | Review Date: January 8, 2018 | Recommended | Price: None indicated
| Rating: 8 |
| Pros: | Very good price/performance ratio for an 80s zoom | | Cons: | COMMENT ON "The only problem I have is that the objects that are very far away are not sharp!" | | Sharpness: 8
Aberrations: 7
Bokeh: 7
Handling: 9
Value: 10
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If a lens won't focus at infinity
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Your lens here is plenty sharp - so the problem is not optical. It is either haze in the atmosphere, mechanical or a result of movement.
The haze issue may be checked on a cold-crisp frosty morning in the mountains when the air is clear. On the coast in the summer is never ideal !
Then - check you are using a minimum of the focal length as shutter speed (200mm lens at ≥1/200th of a second and ideally twice that (1/400-1/500th) you should have minimised camera shake (often it is a rotation movement induce by the shutter press or vibrations transmitted from the mirror inertia). Remember it is better to have a grainy/noisy image that is sharp than smooth photo without resolution.
If a lens still won't focus at infinity that means that it can't move IN far enough.
Generic lens Makers are prone to this as they have to adapt one design of lens to many makes of camera body.
The commonest reason is the lens mount - especially if you are using an adapter; for example Pentax M42 to PK where most adapters are 1-2mm thick. Other times the mount needs loosening and resetting - as heavy zoom lenses - such as this half-kilogram Hoya - can cause strain over time significant enough to loosen the setting.
It can also be caused by the rear element of the lens bumping into the mirror or something else inside the camera body. For example a sensor frame or mirror housing.
Sometimes the lens has been disassembled for cleaning. Tiny errors in re-siting the lens elements can cause this problem. Often tiny thin "shim" washers are found in telephoto lenses to ensure optimal positioning. Gently shake the lens - has an element come loose (the front and rear elements can often be adjusted without lens disassembly and are those most prone to coming loose)?
It might also be that the lens needs to be adjusted. Some can be adjusted to infinity fairly easily. For others, it's very difficult. Doing this at home usually involves
[1] taping some wax paper over the film plane then adjusting the lens while looking at the image through the back of the camera if it is a film one or using the sensor in a digital
[2] Adjusting the helicoid screw inside the lens - which is usually locked with a grub screw at infinity. This is often deep inside the lens structure and can be a real struggle to reach as many lenses are manufactured with only 1-way intent (i.e. are not made to be disassembled)
Unfortunately, there is so much variation in lens design that there are no common instructions for adjusting infinity focus for all lenses.
Best of luck getting this lens right. As the pictures from sosnovska show - this can be a very capable performer and is often way cheaper in the HOYA rather than Tokina or Vivitar versions.
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New Member Registered: June, 2017 Posts: 2
1 user found this helpful
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