Please recommend me some Manual Focus EF lenses!

[kye]

2 hours ago, maxJ4380 said:

I was going to suggest one of those friction clothes, mum has a few in the kitchen drawer for hard to open jam jars. If that didn't work, one drop of wd-40 on the threading left to  sit over night, only one drop mind you as you dont want to find out that wd-40 might be also good at delaminating glass elements

It actually feels like it's in a softer set of threads, so it's not like metal on metal where it grips and then slides easily, this just requires a certain level of force to get it to move and once moving it requires the same force to keep it moving.

I would absolutely never ever put something like WD-40 into an optical assembly!  Not only would it potentially dissolve or melt any plastic it comes into contact with, but solvents can 'wick' into things and spread across surfaces (especially bad if those surfaces are on the inside and you can't get at them to clean them), and solvents will evaporate and likely fill every void or space with fumes, which can potentially condense on the surfaces of the lenses and dissolve the coatings etc.

I've glued things together before with PVA glue, which is water based, and after the glue had dried (ie, the water in it evaporated) it had condensation all over the sensor and lens etc.  I set it on a windowsill in the sun to dry for a few days and it cleared up fine, but I think that was mostly because it was water and that didn't interact in any way with the lens or sensor elements.

[eatstoomuchjam]

Famously, the greases that Leica used in their old lenses would evaporate and deposit on lens elements over time.  It can be cleaned, but the danger of evaporation/depositing is real!

[Emanuel]

39 minutes ago, eatstoomuchjam said:

Famously, the greases that Leica used in their old lenses would evaporate and deposit on lens elements over time.  It can be cleaned, but the danger of evaporation/depositing is real!

Not only the Leica :- )

[kye]

Further lens contemplation reminded me of my Tokina RMC 28-70mm F3.5-4.5 for m42 mount, which is deliciously imperfect, and when combined with an ultra-cheap wide-angle adapter gets even tastier..

I've struggled with this lens because the main issue with it is that it's a dumb lens and so there's no way for the cameras IBIS to know what focal length it's at.  This is fine for tripod work, but that's not really how I shoot, and if it was tripod work is slow enough that I could just use primes.

Then I realised that as I now own an EF speed booster I can get an EF zoom lens and it should report the current focal length to the camera and the IBIS challenge goes away.

As such, I started looking for the absolute worst, most imperfect, least sharp, EF zoom lens I could find.  Luckily, if you search ebay in ascending price it makes these gems obvious and you can peruse at your leisure.

So I have now snapped up a lovely Tokina zoom that according to the Pentax forums has decidedly poor optical performance.  Hooray!!  Pics when it arrives, but I'm excited.  

I was also made aware of the existence of the Tokina AT-X PRO F2.8 zooms, which are interesting, but a long way from the top of the (price ascending) ebay search results.  I also found a couple of the F2.6 Angie designs too, those were $3-4K..  wow!!  Being famous on the internet sure makes things more expensive!