Can a lens cause a metering issue? Nikon FE SLR inconsistencies

sygyzy · May 11, 2013

Hi,

I have two Nikon FE's with two Nikon lenses. I was curious how their metering worked so I did a test.

Equipment:

Nikon FE A - Set for ISO400, No EC, has fresh Energizer batteries measuring about 1.55-1.58 volts each.
Nikon FE B - Set for ISO400, No EC, has mix of old/used generic batteries measuring about 1.50-1.52 volts each.
Nikon 50mm f/1.8
Nikon 35mm f/2.0
Sekonic L308S meter - Set for ISO400 and 1/60th second
Panasonic DMC-LX3 - set for ISO400, No EC, Shutter priority 1/60 second

Setup:
I am standing inside my bedroom and facing the other side of a narrow hall way to drywall frame to the left of the hallway bathroom. To the right is the bathroom which is dark inside, the door is open. It's 4PM in the afternoon and there's a window to the left high, and the sun is shining in.

Results:

Nikon FE A
- 50mm lens - 1/60 is between f/5.8 and f/8
- 35mm lens - 1/60 is exactly f/2.0
Nikon FE B
- 50mm lens - 1/60 is f/8
- 35 mm lens - 1/60 cannot be achieved. f/22 gives 1/1000th reading.
Sekonic light meter
- Facing wall incident: f/2.0
- Facing wall reflective: f/5.6
- Facing lens incident: f/2.8
- Facing lens reflective: f/5.6
Panasonic LX3
- At 1/60th, it reads f/5.6

I assume f/5.6 at 1/60 is the correct metering. How come the 35mm lens gives such bad readings? I also noticed that when I put the 35mm on Nikon FE B, it is really tight. Once it's on, the aperture ring is really tough to turn. The 50mm on Nikon FE B is fine. Both lenses are fine on Nikon FE A. Is this a metering issue or something is wrong with the mechanical coupling of the lens to the body?

Any help would be appreciated.

Tom1956 · May 11, 2013

That's a head scratcher. But before anybody can answer of any worth, you need to do some careful observarton as to why the lens mounts so tightly. Was the lens dropped and the bayonet bent ever so slightly? Obviously it has the camera resistor out of contact, resulting in no reading. Establish trust with the camera that behaves best, then proceed to the other one. Too many irons in the fire means some calves will heal their too-cool brand so that a rustler can re-brand them.

fstop · May 11, 2013

Did you swap batteries so you are comparing apples to apples? Batteries can read voltage in the range that should work but can be weak enough to not deliver enough amperage.

Check the metering coupling ring on the body to make sure it springs back and the tab is in the proper position

rwreich · May 11, 2013

Are you sure the 35mm is notched out for AI? If it isn't, perhaps the connection is getting jammed... of course, I am not an expert.

bdial · May 11, 2013

First off, it seems like you have some sort of mechanical problem between the 35 and FE B, seems likely it may not be engaging the meter coupling lever correctly. The aperture ring should not ever be tough to turn, and if it is, find out what's wrong before turning it more.

Then to get a good test of the metering, first you should either use the same batteries in both cameras or else get a set of fresh batteries for both cameras.
Next, meter some evenly lit featureless surface like a wall so that it fills the frame with both lenses, and meter the same area with the hand held meter (reading off the wall). Make sure there are no shadows in the area you're metering. Better yet, use a grey card.

Incidentally, if by "a mix of old/used generic batteries" you mean that you have mixed battery types, brands or two batteries that have different states of charge (like one newer than the other), get them out of the camera asap, as you are inviting them to leak. (the stronger of the two tries to charge the weaker one causing it to leak).

sbuczkowski · May 11, 2013

This also doesn't really explain your results but, keep in mind that the 50mm and the 35mm (and likely the two meters) have different fields of view. They are integrating light from two related but, essentially, different scenes. When you have the other issues already brought up under control, you may still see differences because of this. A frame filling grey (any color really) card or wall lit with a common light source would be a better test source.

Ambar · May 11, 2013

Added to the suggestions above.. I would also conduct a simpler test and start eliminating variables.
Batteries are swappable and inexpensive for the most part so simply discard the older generic dubious set and use the same fresh set for both cameras.
I would then start by taking both cameras and taking a meter reading with NO lens attached. Same batteries, same NO lens. My FM2n will give a reading.. I believe the FE will as well.
Check the deviation on that and then add the lens variable with the same battery set.
I once did a similar test to check the meter on a couple of camera bodies I had and see how much they deviated from each other. I found it easier to do this at night on a white , (somewhat) evenly illuminated wall.

BMbikerider · May 12, 2013

I think that the type of metering is the answer, not the battery voltage. As good as those meters were - generally - they were inconsistent when it came to differing focal lengths. An inbuilt spot meter in these circumstances would be more accurate so long as the meter was pointed at the same place.
Even my F100 and F80 show different exposures for different focal lengths especially with my 17/35 where the scene contains a large amount of different tone, even using the matrix meter, but are almost parallel when it come to using the spot meter.The simple answer is to meter off a piece of grey card.

Chan Tran · May 12, 2013

Although I wouldn't use the same testing method as you did but I have to say that the problem is in your 35mm f/2.0 lens. Is the lens an AI lens?

BMbikerider · May 12, 2013

I don't think that if it was an Ai or AiS lens would make any difference. It is the difference between the acceptance angles of the different lenses where a wide lens may/will take in more high or low light areas than a shorter focal length lens which will produce the different results. This is one of the main drawbacks of an averaging metering system

Chan Tran · May 12, 2013

BMbikerider said:
I don't think that if it was an Ai or AiS lens would make any difference. It is the difference between the acceptance angles of the different lenses where a wide lens may take in more high or low light areas than a shorter focal length lens which will produce the different results. This is one of the main drawbacks of an averaging metering system

The op didn't say what kind of lens it was. It could be pre AI lens. In such case it could be the cause of the problem.

Lamar · May 12, 2013

Sounds like your 35mm lens is either pre-ai or has a problem with the how the aperture ring engages the AI follower. Some cameras like the F4 have the AI follower on a hinge so you can flip it out to allow mounting pre-ai lenses and stopped down metering. I know the FE2 and most likely the FE has a fixed follower and you should not mount pre-ai lenses.

benjiboy · May 13, 2013

BMbikerider said:
I don't think that if it was an Ai or AiS lens would make any difference. It is the difference between the acceptance angles of the different lenses where a wide lens may/will take in more high or low light areas than a shorter focal length lens which will produce the different results. This is one of the main drawbacks of an averaging metering system

The Nikon FE hasn't got an "averaging metering system" but the standard Nikon centre weighted system, that is, 60% weighted to the central doughnut and 40% from the rest of the screen.

fstop · May 13, 2013

The FE has the flip up tab, if its flipped up with with an AI lens it would read 1000th @ f22 as posted above. Not sure why its stiff.

sygyzy · May 13, 2013

Hi, I realize I am a new member here so I don't want anyone getting the wrong idea. I have been busy this past weekend or else I would have done a retest! I am very appreciative of everyone chiming in with their theories. Let me try to answer as many questions as I can!

Yes, I will try the test again with your suggestions - same batteries in both cameras and preferably a white wall that fills up the entire frame.
Lenses: as far as I can tell, here are the stats of the lenses
- 50mm f/1.8 Nikkor, Type Ai, made 1978-1982
- 35mm f/2.0, Type K, made 1975-1977
I cannot see that the 35mm is damaged at all or anything looks out of place. Of course, I am not an expert on these lenses. I will say that nothing looks GLARINGLY wrong such as chips, dents, bends etc.
Despite both cameras being Nikon FE's (not FE2 or FM, etc), if I look into the lens coupling, they look slightly different. I am not sure why or how this is possible. I will attach a picture tonight.
Why would a Pre-AI lens cause a problem? I bought the FE because I read it was one of the most reliable film SLR's and it's advantage over it's newer counterparts was that it could accept ALL lenses.
I am very careful putting on the 35mm lens on my second FE body. I can't see any issue with me using the wrong angle or too much or too little force or cramming anything in. It's VERY stiff though when attaching and turning the aperture wheel takes two hands, one to steady the lens body and one to twist the ring. Certainly very disconcerting.

Thanks again for everyone's help. I secretly hope it's an issue with it being Pre-Ai ... can someone explain that to me?

Chan Tran · May 13, 2013

I didn't know until now but Nikon type K lenses are the latest of Pre AI lenses. Any yes they were made from 75-77. To use these lenses on the FE you will have to flip the AI coupling out of the way and use stop down metering. Not flipping the coupling out of the way you can damage the camera by mounting the lens. My guess that there is some differences in tolerance between the 2 cameras and thus one move the coupling the other less but both gave you wrong meter reading. Actually both should be tight because the lens hit the coupling.

sygyzy · May 13, 2013

I have no idea what an AI coupling is so I will investigate as soon as I get home from work!

rwreich · May 13, 2013

That was my take on it... back from post #4 in this thread;-)

Lamar · May 13, 2013

Fstop said there is a flip out ai follower on the FE and from what you say the 35mm lens is pre-AI and won't have the AI cutout on the aperture ring of the lens , which is where the AI follower on the camera engages the aperture ring on the lens. The follower moves around the circumference of the lens mount and gives the camera aperture info it needs for metering. If you don't know about the flip out follower then you are probably mounting the pre-AI lens incorrectly with the follower in it's normal position.

See the pic of my F4 with the follower in it's normal position for AI lenses:

For pre-Ai lenses the follower should be flipped out. I don't know how it's done on the FE but on the F4 there is a small pin on the follower that you depress allowing it to be flipped out:

Here is an AI lens that has the cutout for the AI follower just below the coupling prong (metal bit that is sticking up):

And a pre-AI without the cutout. Note the smooth aperture ring base with no notches:

Here is a picture of the pre-AI lens on the F4 with the follower flipped out. Note the lens is not binding because the follower is moved out of the way:

And here is a picture of the Ai lens being mounted with the follower up in its normal position for AI lenses. Note the AI cutout on the lens. In this pic I haven't fully rotated the lens yet to lock it but when I do the notch in the lens engages the follower and rotates it.

The non-flip out AI follower on the FE2 doesn't allow for use of pre-AI lenses without modification:

Just for good measure this is how the meter coupling works on the non-AI cameras:

Tom1956 · May 13, 2013

Well, post #2 was mine, and was a failed attempt at humor, until more info was brought to light by the OP. Having worked on a number of camera meters, I've see the wide-open metering can differ from the reading obtained by stop-down, among the 2 lens styles. This points to a weak meter cell on the camera with such a big variation from all other instruments used in the comparison tests.
I maintain the same position now as in the corny analogy; that camera 1 and meter 1 were out of agreement by a full stop. At that point the introduction of a second camera would only confound the finding of the culprit as to why camera 1 and meter 1 were a stop apart. So far, not a single piece of gear mentioned ended up close enough in agreement to know where the accuracy was. Chasing down the truly accurate meter is one of the toughest things I've ever done. But it needs to be found in these kinds of tests. One of those camera meters or one of the hand-helds is the truest, and emerges as the standard.

Chan Tran · May 14, 2013

The Sekonic 308 has a 40 degrees angle when measuring reflected light. That's the same coverage of a 50mm lens but the Nikon is center weighted giving more weight to the center thus their readings are a bit higher. The FE#2 is different from #1 about 1/2 stop which is normal. When measuring incident light the Sekonic read 2 stop lower because the wall is about 80% reflectance instead of 18%. Pointing the reflected light meter toward lens or pointing the dome toward the subject when in incident mode don't make good reading. So I have to concluded that there was something wrong with the 35mm lens. Having wider angle should result in somewhat lower reading but not as much as the OP experienced.

E. von Hoegh · May 14, 2013

sygyzy said:
Hi, I realize I am a new member here so I don't want anyone getting the wrong idea. I have been busy this past weekend or else I would have done a retest! I am very appreciative of everyone chiming in with their theories. Let me try to answer as many questions as I can!

Yes, I will try the test again with your suggestions - same batteries in both cameras and preferably a white wall that fills up the entire frame.

Lenses: as far as I can tell, here are the stats of the lenses

50mm f/1.8 Nikkor, Type Ai, made 1978-1982

35mm f/2.0, Type K, made 1975-1977

I cannot see that the 35mm is damaged at all or anything looks out of place. Of course, I am not an expert on these lenses. I will say that nothing looks GLARINGLY wrong such as chips, dents, bends etc.

Despite both cameras being Nikon FE's (not FE2 or FM, etc), if I look into the lens coupling, they look slightly different. I am not sure why or how this is possible. I will attach a picture tonight.

Why would a Pre-AI lens cause a problem? I bought the FE because I read it was one of the most reliable film SLR's and it's advantage over it's newer counterparts was that it could accept ALL lenses.

I am very careful putting on the 35mm lens on my second FE body. I can't see any issue with me using the wrong angle or too much or too little force or cramming anything in. It's VERY stiff though when attaching and turning the aperture wheel takes two hands, one to steady the lens body and one to twist the ring. Certainly very disconcerting.

Thanks again for everyone's help. I secretly hope it's an issue with it being Pre-Ai ... can someone explain that to me?

There's your problem."[*]35mm f/2.0, Type K, made 1975-1977". This lens does not couple with the meter in your camera, it is what's called a "pre-Ai" lens. If you look in the instruction manual for your camera, it will explain how to use stop-down metering.

E. von Hoegh · May 15, 2013

sygyzy said:
...snip
[*]I am very careful putting on the 35mm lens on my second FE body. I can't see any issue with me using the wrong angle or too much or too little force or cramming anything in. It's VERY stiff though when attaching and turning the aperture wheel takes two hands, one to steady the lens body and one to twist the ring. Certainly very disconcerting.
[/LIST]

Thanks again for everyone's help. I secretly hope it's an issue with it being Pre-Ai ... can someone explain that to me?

This should have been your first clue. Nothing, absolutely nothing on any camera requires that much force unless something is very very wrong. Whenever something requires that much force to move, STOP and find out why.

sygyzy · May 15, 2013

Hi everyone, thanks again for your expertise and help. I am new to all this and learned lots about the different Nikon lenses and the the mechanics of the camera. I tried flipping the tab up and of course the 35mm fits like a treat. Now I need to figure out stop down metering (by reading the manual).

Lamar your photos were ESPECIALLY helpful. Thank you for uploading them.

GarageBoy · May 15, 2013

Stop down metering is exactly what is
Hit the DOF preview to stop down the lens, take your reading and shoot
or in AE mode, press down DOF preview, and shoot

Can a lens cause a metering issue? Nikon FE SLR inconsistencies

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