Minolta af 35-70 f4 aperture
I have just realised the aperture blades on my copy of this lens are sticky! This means it doesn't stop down correctly - it gets to about f5 and slightly sluggishly opens again.
Does anyone know how I might repair this? Cheers in advance!
So, I was waiting to see if anyone else would chime in with more helpful information. I have never cleaned aperture blades before but know it can be done DIY. I have only ever cleaned the lens elements before which at least for front elements is straight forward. I imagine accessing the blades would require going from the rear or at least further down the front which always complicates things, and then require some care not to break any of the springs/systems that manipulate the blades.
Thanks - I found a teardown of the lens and I decided that maybe wide open is just fine!
I can pick up another for a song anyway... 🙂 maybe in a few months I'll grab one. Still has use wide open.
Looking at my copy of that lens, you'd need to open it up from the back.
I'm no pro but taken a handful of lenses apart. Generally my thoughts are:
- Find a guide or YouTube video
- Failing the above, decide if you have nothing to loose by taking the lens apart. AF lenses are typically harder.
- If you decide to get adventurous, then get a good set of tools. Precision screw drivers, plastic guitar pics, lens lock ring spanner, tweezers of various types, mini suction cup, lens cloth, cleaning solution / isopropyl alcohol.
- setup a clean area to work in. Make sure that whatever you drop (you will drop screws!) you can find. IE don't work over black shag carpet.
- take pictures along the way.
- if you encounter a situation where you don't have the right tool, just stop. Put the project away (where the kids and dog won't find it) and resume when you have the right tool.
- don't take apart more than you need
- cross your fingers!
I normally don't attempt this unless the lens is worthless otherwise (with the exception of my Tamron 70-200 which I take apart now and then because it inhales dust). I have cleaned oily aperture blades on a handful of breach lock canon FD lenses and a MF Vivitar zoom. Each time I hit that moment ... "what have I just done". Once you accept the lens may be trashed, it can actually be fun for an evening trying to take it apart.
Good luck whatever you do!
Cheers. I'll consider having a go if I find a cheap replacement - then I either have a spare, or I can pass on a freebie to someone like you!
So if anyone runs across this the easiest way to remove oil from blades is lighter fluid. It eats the oil up and evaporates within seconds.
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