Search results for 'back focus' - page 2125
Problems with Sigma 24mm Superwide lens
Hi, seem to be getting a few problems lately, turns out my focusing issue with my K5 was more down to user error than camera error but now I have a different problem. I have a manual focus Sigma 24mm f2.8 lens and for some reason the when I change the aperture on the camera it will not go down past...
Posted by bigdaddybucks on 17/09/2015 - 17:12
Problems with Sigma 24mm Superwide lens
I used to have the manual focus "A" version and now have the AF version, both work(ed) fine down to f2.8 on my K5. Normally the problem is dirty contacts on the lens (or occasionally body) Give them a clean with a lens cloth and see if that helps.
Posted by StephenHampshire on 17/09/2015 - 19:42
Lack of infinity focus with m42 adapter
Hi all, I'm new here and haven't been able to find help with this via a search, so here is my question: I have just bought a Super Takumar 50/1.4 in m42 thread mount. I recently learned what a legend this lens is. I just received a Fotodiox m42-Pentax K mount adapter so that I could use the lens on ...
Posted by BazK on 30/09/2015 - 08:10
Lack of infinity focus with m42 adapter
I'd be very surprised if it is the lens. To reach infinity you need an adapter that sits right within the K mount. Some cheaper models have a flange that moves the lens further out, loosing infinity focus. There are cheap adapters without the flange. I tend to remove the spring from one of the...
Posted by petrochemist on 30/09/2015 - 08:16
Lack of infinity focus with m42 adapter
The Pentax Adapter K fits flush inside the mount and allows infinity focus. You need an adapter that fits the same way. Any thickness will prevent infinity focus and such adapters are only good for close up use. It's just the way your adapter is designed that's the problem, so it's not really fit...
Posted by johnriley on 30/09/2015 - 08:16
Lack of infinity focus with m42 adapter
Thanks Mike and John. I was pretty sure the fault was with the adapter. I note that some adapters get around this problem by incorporating a lens element to achieve infinity focus, namely the Fotodiox adapter for Nikon cameras. This utterly defeats the purpose in my opinion. I would never compromise...
Posted by BazK on 30/09/2015 - 09:01
Lack of infinity focus with m42 adapter
Just found the answer to my question. I saw the Shop tab on the menu bar. I'll try there for a Pentax Adapter K.
Posted by BazK on 30/09/2015 - 09:04
Lack of infinity focus with m42 adapter
You might find one on eBay at a reasonable price.
Posted by johnriley on 30/09/2015 - 11:11
Lack of infinity focus with m42 adapter
I've used the same cheap adaptor on a few lenses and just one of them won't focus past a meter or so ahead of me. It can happen, but the first place to check is with another adapter.
Posted by richandfleur on 30/09/2015 - 14:12
Lack of infinity focus with m42 adapter
Thanks, I had the same comment from Fotodiox - they suggested that I return it and ask for a replacement. They said: "Most of our adapters focus to infinity before the infinity focus mark on the lens, if this is not the case maybe the is an issue with the adapter". I'm a bit surprised they admitt...
Posted by BazK on 30/09/2015 - 22:11
Lack of infinity focus with m42 adapter
It sounds like the adapter you have is one with a big, thick flange that sticks out from the mirror box after inserting it (like the top one of those shown here). You need one like the lower pair (showing front and back). They are available now and then on Ebay. The genuine Pentax ones fit to pe...
Posted by davidwozhere on 01/10/2015 - 00:48
Lack of infinity focus with m42 adapter
I measured mine this morning and it's only 0.62mm in thickness - hard to imagine anything thinner, and possible even thinner than the ones above. It seems that the genuine Adapter K is the best option. I'm assuming that this one stays in the camera and that other m42 lenses screw into it, rather tha...
Posted by BazK on 02/10/2015 - 01:01
Lack of infinity focus with m42 adapter
Any flange at all will loose infinity for wide angles, as you say it wouldn't be practical to make a flange much thinner, but you need to get about 100 times thinner before you're getting the sort of tolerances required. Longer focal length lenses get to be more tolerant needing more extension to af...
Posted by petrochemist on 02/10/2015 - 08:24
Lack of infinity focus with m42 adapter
To attach the adapter, first attach it to a lens. Then bayonet it onto your camera. After that, just screw lenses on and off in the usual way, you have effectively converted your bayonet camera into a screw thread one. So just one adapter is all you need. To remove, hold the camera mount down,...
Posted by johnriley on 02/10/2015 - 09:10
Lack of infinity focus with m42 adapter
Just check that the flush-fitting adapter will release easily! The genuine Pentax ones do, and so does a second-hand one marketed by Jessops that I bought a while ago. It was much cheaper than second-hand Pentax brand ones usually are. Beware of some of the cheaper flush-fitting adapters. It can...
Posted by OldTaffy on 02/10/2015 - 18:05
Lack of infinity focus with m42 adapter
the Kood i have came with a release key and has never given a problem to remove, don't push the key all the way down, only go just enough to actuate the spring when rotated
Posted by redbusa99 on 02/10/2015 - 18:52
Lack of infinity focus with m42 adapter
Thanks for the helpful comments everyone. I've learned a lot. And it seems my troubles may not be quite over, as I've also bought a couple of wides, 35/3.5 and 28/3.5, both Super Takumars. If infinity focus is more critical for wides, I might run into more trouble. However there are no problems like...
Posted by BazK on 02/10/2015 - 22:31
Lack of infinity focus with m42 adapter
Fortunately, I don't bite my fingernails and therefore have the perfect adapter spring release tool on the end of my right thumb. Forefinger against the inside of the mount, thumbnail releases spring and grips the metal ring which can be gently rotated out. I have found no problem with infinity on a...
Posted by davidwozhere on 02/10/2015 - 23:39
Lack of infinity focus with m42 adapter
Thanks for the helpful comments everyone. I've learned a lot. And it seems my troubles may not be quite over, as I've also bought a couple of wides, 35/3.5 and 28/3.5, both Super Takumars. If infinity focus is more critical for wides, I might run into more trouble. However there are no problems like...
Posted by petrochemist on 03/10/2015 - 08:26
Lack of infinity focus with m42 adapter
I'm entirely uncertain about having an adapter on each lens because either the spring will have to be forced every time you remove it or you will have to remove the spring (giving a plain bayonet on the end of the lens). In this latter case, there is now no locking mechanism and you could easily twi...
Posted by petrochemist on 03/10/2015 - 08:30
