graybeard

I am an old film shooter and have avidly gone digital. But I still use a lot of my old M42 mount lenses with a Canon adapter. Generally, results are good, but I do have a question. What part, if any, does the aperture ring on my old lens play ? When I shoot manual, I am in the habit of setting my camera ap to say 1.4 and my ring to the same. When I do this everything seems fine. But I am thinking is 1. set aperture ring to most open setting 1. set camera aperture to whatever you want as long as it is not lower than the ring setting. Is this right ??

speters Loc: Grangeville/Idaho

If you shoot in manual, all you need, is to set the lens to the required aperture, than that's it! Aperture set, simple!
That's what gives you the desired DOF. No need to set anything on/in the camera for that, with an M42 adapter, you do not have the communication between the lens and camera! You can see the working aperture in the viewfinder, or if you want in live view!

graybeard

I am not sure about communication. I am able to meter OK. Then according to you, the lens ring does it all. But what about camera setting? Isn't there a conflict here?

brucewells Loc: Central Kentucky

I know little about this, but my older Nikkor “D” lenses had an aperture lock at f/22, if I remember correctly. From there, the camera managed it all.

frankie c Loc: Lake Havasu CIty, AZ

If you use a manual lens on your new school digital camera/DSLR/Mirrorless.. the meter works just fine. Somewhere on your camera you have a meter scale/the new version of the old needle in the circle usually a set of tick marks with a scale reading with 0 in the center indicating the correct exposure. If you are using Manual mode adjusting either the aperture (via the aperture ring) or changing the shutter speed will adjust/change the position across the scale indicating a change in exposure. Get it to center at 0 and there is your recommended exposure. If you are in any other mode the meter still works the same way as it did on your OLD SLR. I use old lenses on both my Nikons/DSLR and my Olympus/Mirrorless.... never had a problem. I hope I explained this well enough and It helps. I did not mention ISO but this is also an adjustable factor to obtain the exposure you desire Using the cameras meter. Good Luck and have a great day.

BebuLamar

Yeah right! You said new school digital camera/DSLR so I think there are quite a number of Nikon DSLR's are old school and the meter simply doesn't work. Namely the Nikon D5xxx and D3xxx like the D5600 and D3400.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

I use a number of old manual lenses on my Canon DSLRs. To get accurate metering they need to meter in stopped down mode, although they focus more easily wide open. This works with adapted Canon FL/FD/FDn lenses, Contax, Nikon, and M42 Helios lenses. They are fun, but it helps to have full control over the aperture to have full aperture to confirm focus, then stop down to meter and get the preferred expose / depth of field. It works well in either manual moder or aperture priority with most lenses so long as there is aperture control manually.

alycat Loc: Canton OH

They used to make"pre-set lenses. You would set shooting apature on one ring, and rotate another ring to wide open, focus and compose, rotate the ring to the preset apature and shoot.

graybeard

Thank you for your reply. I wasn't questioning how to read a light meter. I was wondering, in the camera's "brain" how it reconciles an f stop dialed in the camera versus an f stop dialed in the lens aperture ring. I know it can be done wrong, because I did it !!

blackest Loc: Ireland

It doesn't really, there is no way for the camera to control the f-stop. it measures the light and calculates an exposure for that light entering the camera. That light may be because you are shooting at night or because you are stopped down to f16 it doesn't matter. With most manual lenses focus wide open in aperture priority mode so the camera has best shot at finding focus and then stop down to get the depth of field you want. In aperture priority mode you will see the shutter speed drop as you stop down. Unless there is an auto manual switch which switches between open and stopped down modes in which case you just see the wide open and stopped down shutter speeds.

Pentax does it differently with km lenses there is an aperture lever normally held open which is released when the shutter is pressed stopping down to the aperture on the ring because its impossible to predict what that will be automatically pentax has the green button in manual mode which you press it releases the aperture lever stopping down and taking a meter reading to set the shutter speed. when you press the shutter button it uses the exposure calculated from the green button press and releases the aperture lever and takes a photograph.

Later ka lenses also use an aperture lever but the movement is proportional to f-stop and it releases the lever to a controlled amount. Doing the same kind of mental calculation you might do say knowing that the shutterspeed is say 1/200th for wide open at f2.8 then f4 would be be 1/100th. Part of the magic of the ka lens is a lens code which gives the max and minimum apertures for the lens which lets the camera know how much to release the aperture lever for any f-stop.

frankie c Loc: Lake Havasu CIty, AZ

The camera doesn't have a brain it has logic circuits. The brain is all us :) anyway. the camera doesn't reconcile the fstop the fstop reconciles the meter.... if you are using a completely manual lens (the lens cannot be read by the cameras electronics) then you turn the aperture ring to adjust the amount of light coming into the camera. things like shutter speed and ISO are part of the camera's internal logic therefore can be set by the cameras logic/via turning a dial or changing it in the menu. There are lenses that couple and can be read by the cameras electronic sensors that also have aperture rings. Usually those get set in a locked position on the camera at usually f22 and after that the cameras logic takes over and when you set the aperture on the camera the lens response to the chosen f stop when the shutter button is pressed. So you are kind of comparing apples and oranges. Usually the first example is when using a lens that is not compatible with the cameras electronics. The second is a lens which is compatible electronically (those little contact points on the lens match the cameras contact points). They only line up correctly if you lock the lens at the correct fstop setting (usually fully closed).... Usually your talking about a systems generation of lenses for a given series of cameras. Nikon D series lenses and earlier usually have aperture rings. G series lenses do not. The older lenses are still compatible with the newer camera bodies. The newer series lenses are not compatible with the older camera bodies. That's why you can still use your SLR lenses on the new cameras DSLR and you can't use your new lenses on the old cameras/SLR's. That's the best I can do splaining. I wish you well. Thank you for wadding through my splaining :)

graybeard

There are supposedly 3 type of adapters. The simplest just facilitates the mounting of the lens, in my case M42 to Canon. Next comes one with chips on the back, just like a Canon lens chips. It is called A/F confirm or something like that. This ring seems to be black in all the examples I have seen. The third type is silver, and it is called "programmable" where you set lens speed, focal length and a few others I forget. The process is extremely tedious. Anyway, I have types 2 and 3, and can't discern any difference (other than price) between them. When in mode M everything works fine when I set the f stop in the camera to match the lenses aperture ring, and the shutter speed and ISO match to fit the exposure triangle. The light meter goes back and forth as I adjust either the shutter speed or aperture ring, just as if I had an automatic lens on. I get over and under exposures if the lens setting and camera setting for the f stop are different. Or so it seems to me. Did I splain that right ??

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Each camera brand is different, but you seem to have the basics about right for Canon. The color of the adapter is irrelevant, it either has a chip that allows focus confirmation or it doesn't. The chips vary in whether they can be programmed or not, and how complex it is to do. It's useful if each chip / adapter is dedicated to a specific lens, but not for an adapter used with different lenses in my experience.

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

Except for base model DSLR's, Nikon makes it easy to use older lenses with Nikon F mounts (except Pre-Ai mount). Shooting in Aperture preferred, you set the aperture with the ring, and the ISO, then the camera sets the shutter speed and the aperture is held open until the shutter button is pressed. The consumer & upper-level Nikons will meter in aperture & manual modes with older lenses and there is no need to set anything other than the shutter speed & ISO on the camera, no stop down metering needed. I use an Olympus mirrorless camera for all of my older non-Nikon mount lenses since they don't adapt well with adapters due to Nikon's long registration distance. Not sure if Canon adapted lenses hold the lens aperture open until the shutter is tripped or whether they have to be shot as a preset lens would. Either way, there is no need to fiddle with the knob that controls the aperture on the camera body. That's just for electronically controlled lenses.

speters Loc: Grangeville/Idaho

Yes, the meter works fine, that's why I said, you do not need to do any more than that for adjusting the aperture,. You'll be able to see the working aperture through the viewfinder (just like DOF preview)and the camera as well acknowledges the aperture set and will meter accordingly! You will however need to set all the other parameters yourself, since you're in manual!