help which type of converter?

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young_turk

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Hi I have the Nikon d3100 with the basic kit lens.

I want to use some of my dads old lenses from his SLR, it is a Chinon

He has various lenses, Chinon, Sigma and a Miranda all have the same attachment threads.

What converter would I need to get to enable me to use them on the DSLR?

They have the Pentax K stamp on the lens covers.

Many Thanks
 
Hello and welcome to TP.

Unfortunately, what you're trying to do isn't a particularly good idea. If you can get an adapter to make the lenses fit, you won't be able to focus them on subjects in the distance. So they won't be terribly useful.

Here's why.

Any given type of lens mount (Canon FD, Nikon F, Olympus OM, etc etc) has a design characteristic called the registration distance or the flange distance. This is the distance between the plane of the sensor (or film) and the flange on the lens mount - the back of the lens, in other words.

Your dad's Chinon camera will have used the Pentax K mount which has a flange distance of 45.46mm, which means that the lenses need to be mounted 45.46mm away from the sensor to work properly. But the Nikon F mount on your camera has a flange distance of 46.5mm, which means Nikon cameras hold the lenses 46.5mm away from the sensor. If you stick an adapter in there, you can only increase the distance between the lens and the sensor, so you simply can't achieve the 45.46mm you need for Pentax K lenses. The result is that the lens doesn't work 'properly' - in particular, you can't achieve infinity focus. You need extra bits of glass in the adapter to achieve that.

It could work the other way round - you could get an adapter to mount a Nikon lens on a Pentax / Chinon camera. (The adapter would have to be 46.5-45.46 = 1.04mm thick.) But obviously that's not much use to you.

There are lots of web sites with tables of flange distances for different mounts. Here is one on Wikipedia. Here is another.
 
Last edited:
StewartR said:
Hello and welcome to TP.

Unfortunately, what you're trying to do isn't a particularly good idea. If you can get an adapter to make the lenses fit, you won't be able to focus them on subjects in the distance. So they won't be terribly useful.

Here's why.

Any given type of lens mount (Canon FD, Nikon F, Olympus OM, etc etc) has a design characteristic called the registration distance or the flange distance. This is the distance between the plane of the sensor (or film) and the flange on the lens mount - the back of the lens, in other words.

Your dad's Chinon camera will have used the Pentax K mount which has a flange distance of 45.46mm, which means that the lenses need to be mounted 45.46mm away from the sensor to work properly. But the Nikon F mount on your camera has a flange distance of 46.5mm, which means Nikon cameras hold the lenses 46.5mm away from the sensor. If you stick an adapter in there, you can only increase the distance between the lens and the sensor, so you simply can't achieve the 45.46mm you need for Pentax K lenses. The result is that the lens doesn't work 'properly' - in particular, you can't achieve infinity focus. You need extra bits of glass in the adapter to achieve that.

It could work the other way round - you could get an adapter to mount a Nikon lens on a Pentax / Chinon camera. (The adapter would have to be 46.5-45.46 = 1.04mm thick.) But obviously that's not much use to you.

There are lots of web sites with tables of flange distances for different mounts. Here is one on Wikipedia. Here is another.
Click to expand...

I surprised the swear filter didnt kick in! ;) :lol::lol::lol:

Sorry, I'm very immature... :|
 
Ok thanks for your reply I think that sorts it out for me. I wanted to try to practice the basic stuff using my dads kit prior to purchasing other lens, but it looks like I will have to do some more reading around and get another lens anyway now. I am enjoying using the kit lens.

Thanks again
 
A cheaper way is to buy a M42 converter from say eBay for a couple of pound then buy the old Pentax screw lenses for a few quid each.
 
Your dad's Chinon camera will have used the Pentax K mount which has a flange distance of 45.46mm, which means that the lenses need to be mounted 45.46mm away from the sensor to work properly. But the Nikon F mount on your camera has a flange distance of 46.5mm, which means Nikon cameras hold the lenses 46.5mm away from the sensor. If you stick an adapter in there, you can only increase the distance between the lens and the sensor, so you simply can't achieve the 45.46mm you need for Pentax K lenses. The result is that the lens doesn't work 'properly' - in particular, you can't achieve infinity focus. You need extra bits of glass in the adapter to achieve that.
Click to expand...


I have the NIKON specific m42 adaptor with the correction lens built in to make it work on Nikon, I can then use my old Chinon lenses , but they aren't terribly good, in fact even though i have a 50mm f1.4 it is unusable below f3, so may as well use the kit lens.
 
You can use optional lenses but it really doesn't give look and feel to your photographs.
It will not be able to focus subjects clearly.You must try original lenses and it will be a better option as compare to use other lenses and converter is really not a good idea as it affects the quality of photo.
 
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