Using M42-mount lens on Nikon camera (Page 2): Been there, done that.... Not worth the time and effort. The elements in most of the adapters are sub par and ,as noted, the mechanical...

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

Been there, done that.... Not worth the time and effort. The elements in most of the adapters are sub par and ,as noted, the mechanical only adapters will not allow infinity focus (they only focus to several feet out). I never tried the expensive optical correction adapters, but if I'm going to spend that kind of money, it will be on something more compatible with fewer "gotcha's". I use my orphaned film era lenses on my Olympus mirrorless (except for my older Nikon F mount lenses) as I can use a simple mechanical adapter and still get infinity focusing. I have older screw mount M42, Leica M39, Konica, Minolta, Pentax & Canon film lenses that I use this way. Forget trying to adapt the older M42 to your Nikon DSLR, it's not worth it.

Architect1776 Loc: In my mind

rehess wrote:

I'm wondering whether anyone knows for certain how much a particular correction lens affects IQ.

A correction lens is needed. It does affect the quality.
How much depends on the quality of the adapter.
I use FD lenses on my EOS cameras with such an adapter and bout a less expensive one, it sucked. Bought an expensive one and it was pretty good, still some loss but on the web hard to tell at all.
I am lucky that the M42 on the EOS does not require a glass element to get infinity.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

It all depends on the registration distance of the camera. Nikon has one of the longest registration differences and thus few other mounts can be successfully adapted to it unless an element is added... See this link for flange distances

https://en.wikipedia.org/wiki/Flange_focal_distance

Architect1776 wrote:

A correction lens is needed. It does affect the quality.
How much depends on the quality of the adapter.
I use FD lenses on my EOS cameras with such an adapter and bout a less expensive one, it sucked. Bought an expensive one and it was pretty good, still some loss but on the web hard to tell at all.
I am lucky that the M42 on the EOS does not require a glass element to get infinity.

Architect1776 Loc: In my mind

Screamin Scott wrote:

It all depends on the registration distance of the camera. Nikon has one of the longest registration differences and thus few other mounts can be successfully adapted to it unless an element is added... See this link for flange distances

https://en.wikipedia.org/wiki/Flange_focal_distance

Exactly.
I wonder if it was planned by Canon when they developed the R mount to be able to attract Nikon owners to get a simple adapter so they could switch and possibly the same thought when the EOS system was developed as the Nikon lenses adapt to it with a simple adapter not needing additional optics.

wilsondl2 Loc: Lincoln, Nebraska

T mount lenses are 42mm but have different threads than the Pentax 42mm. T mounts work on Nikons. Most T mount lenses lenses were pre sets. 9look them up0 Mine work in A on my D7100 but not on my D90. So all manual with some cameras. - Dave

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

T mount lenses have a 55mm flange distance and are 42 X .75 thread pitch, Pentax Screw mount (M42) are 45.46mm flange distance with a 1.0 mm thread pitch. Do not attempt to use one on the other as you will ruin the threads since the pitch is different.. The D90 does not meter with manual lenses and the D7100 does, that is why the T mount lenses will meter on your D7100 in either A or M modes but not the D90.

wilsondl2 wrote:

T mount lenses are 42mm but have different threads than the Pentax 42mm. T mounts work on Nikons. Most T mount lenses lenses were pre sets. 9look them up0 Mine work in A on my D7100 but not on my D90. So all manual with some cameras. - Dave

Architect1776 Loc: In my mind

wilsondl2 wrote:

T mount lenses are 42mm but have different threads than the Pentax 42mm. T mounts work on Nikons. Most T mount lenses lenses were pre sets. 9look them up0 Mine work in A on my D7100 but not on my D90. So all manual with some cameras. - Dave

M42 as asked about by the OP and is the "Pentax" screw mount The T mount series is a completely different system using camera adapters.

JPL

rehess wrote:

How difficult is it to use a M42-mount lens on a Nikon camera??
{Yes, I understand that everything will be manual - I'm interested in the mechanical connection}

I have tried adapting different lenses to different cameras. If you need adapter with glass for infinity focus it is not worth it. If you are adapting to lets say mirrorless camera where you will not need adapter with glass for infinity focus it often gives you excellent results. Bascially the rule is to avoid adapting to dslr and if you want to use old glass and adapters you need a mirrorless camera for that.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

Thankfully my older Nikon film lenses all work on all of my Nikon DSLR's (I only have 2 Pre-Ai Nikkors that won't work on the DSRs)

JPL wrote:

I have tried adapting different lenses to different cameras. If you need adapter with glass for infinity focus it is not worth it. If you are adapting to lets say mirrorless camera where you will not need adapter with glass for infinity focus it often gives you excellent results. Bascially the rule is to avoid adapting to dslr and if you want to use old glass and adapters you need a mirrorless camera for that.

Architect1776 Loc: In my mind

JPL wrote:

I have tried adapting different lenses to different cameras. If you need adapter with glass for infinity focus it is not worth it. If you are adapting to lets say mirrorless camera where you will not need adapter with glass for infinity focus it often gives you excellent results. Bascially the rule is to avoid adapting to dslr and if you want to use old glass and adapters you need a mirrorless camera for that.

You would be surprised at how many old lenses adapt to EOS system and do not require glass in the adapter for infinity.
Including, Exacta, Olympus M, M42, Pentax K, T Mount (Oviously) and Nikon to name some more popular ones.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

That fact drives up the prices on older Nikon MF lenses. Plus the fact that many Canon video shooters use older Nikon glass too and they de-click the aperture rings.

Architect1776 wrote:

You would be surprised at how many old lenses adapt to EOS system and do not require glass in the adapter for infinity.
Including, Exacta, Olympus M, M42, Pentax K, T Mount (Oviously) and Nikon to name some more popular ones.

texaseve Loc: TX, NC and NH

I just bought one on eBay yesterday and read reviews on Amazon that said even with the glass, most adapters won’t focus to infinity.

rehess Loc: South Bend, Indiana, USA

Thank you to everyone who replied! I have better understanding than I did yesterday.

Kuzano

RWR wrote:

It acts as a 1.4X teleconverter. I don’t believe there is a light loss, but haven’t actually checked that.

Typically a 1.4x teleconvertor would kick in a one stop light loss. Presuming these adaptors have the same 1 stop loss.

RWR Loc: La Mesa, CA

Kuzano wrote:

Typically a 1.4x teleconvertor would kick in a one stop light loss. Presuming these adaptors have the same 1 stop loss.

I normally just go by the camera’s meter, so haven’t noticed. I plan to run some tests soon with M42 and Exakta adapters, with and without the glass, and will check for sure.