[Johnny Brown]

at that limit its 'nearly' ok

At the limit it looks fine - at least for a shaky hand on a dull day with an old lens. Dan's left leg is showing impressive resolution considering the lighting, the inherent low contrast of an old lens wide open, and the movement blurring. The flowers in front of Grimer equally look fine.

and then gets progressively worse as you tend towards infinity

This is the phenomenon we discussed earlier, known as 'depth of field'. Depending on the parameters you decide, some of that may be acceptable, some not, but the lens is actually focussed only at the point of maximum sharpness. The longer the lens, and the larger the sensor, the more quickly you will see acceptable sharpness drop off as you move in front/ beyond the focussed distance.

[Paul B]

so by stopping down a bit I can use the lense nearer the focussing limit because of the increased 'acceptable' level of focus.

[Johnny Brown]

Yes - but a 135mm on a Dx sensor will never give a huge amount.

eg, at f16:

Subject distance      10 m
 
Depth of field
Near limit     8.59 m
Far limit     12 m
Total     3.38 m
 
In front of subject     1.41 m (42%)
Behind subject     1.97 m (58%)
 
Hyperfocal distance     60.1 m
Circle of confusion     0.019 mm

Problem is, at f16 on a dull day at Kilnsey you'll need a tripod and 1/4 sec to get the lens steady, but your climber will still be blurred.

Get busy with those grub screws.

[dave]

crazy solution: use it on a praktika body?

[Paul B]

its f*cked. It was more like I had this stuff kicking about in a cupboard so for 12 quids worth of adapter it seemed worth a punt.

I'll get on those grub screws when I can find a 'driver small enough. I take it its likely to be the three on the focussing ring and not any others?`

[Johnny Brown]

They'd be the ones I'd try first. You should find the ring comes loose and you can set it so you have more movement in the direction you want.

If that doesn't work, take the mount end off the lens and see if there's a screw/lug which limits the movement, and if you can adjust it.

[SA Chris]

I'll get on those grub screws when I can find a 'driver small enough

You can get a set of watch screwdrivers for about a fiver. Worth it if you are going to be fiddling around with lenses and stuff.

[lagerstarfish]

crazy solution: use it on a praktika body?

That's just crazy talk.

His adaptor is for Canon EF

[slackline]

Nikon Fisheye anyone?

[dave]

Is that the ones made for taking 220degree circular fisheye shots with the lens pointing directly up into the sky? I read somewhere they were designed for polar expeds, basically stand the camera on the floor and you get a full horizon in all directions. Monster.

[Paul B]

Hadn't really used the MF lenses since JB tweaked them for me but the results seem somewhat improved, behold: Uncle Tradbury.


Uncle TRADbury by travelswithmyt4, on Flickr

[cofe]

This gave me a pretty epic boner this morning. Not been able to find what it locks at for APS-C sensor cameras mind. I'd hope no more than 10-11mm.

[slackline]

I also need these lenses ........Thanks to share information about it .

  Another  ?