[BruceBanner]

Hey everyone,

I was linked this page in a different thread, and I got to studying it when something jumped out at me;



Circled blue 'Spot metering connected to AF point'. For a start I didn't think this was possible. When using 'Spot' metering (as opposed to Matrix or Centre) I thought it was always dead centre. For example, if you chose your focus point to be 'SEL' and chose a red dot/square to be the focus point that wasn't dead centre (say to a pretty far right position for example), then trying to do that with those settings wouldn't work (unless of course that was the desired effect, silhouette etc).

But that suggests that if you turn the subject matter menu item on (select 2), then that indeed would shift the Spot meter with the chosen AF point in SEL mode?

But then i am also doubly confused because circled red you can see he has Matrix as the metering, not spot. Can anyone weigh in here and tell me what's going on?

I have a feeling I have been missing out on utilizing a great feature!

Cheers,

Bruce

[Ex Finn.]

then that indeed would shift the Spot meter with the chosen AF point in SEL mode?

It does. Is there some setting maybe disabling that with your K1?

[Ex Finn.]

KP can do the same also.

[BruceBanner]

It does. Is there some setting maybe disabling that with your K1?

Thanks for replying.

I realise it can do it (by the fact it's in the options lol), where I'm more confused over is having the setting on when in Matrix mode (as circled red with the above chart). This guys an awesome photographer so it's not accidental. He's choosing to show the fact that Matrix is his metering but also has ' C Menu 1 - 5 Link AE and AF Point' as being 'on' (by way of showing 'Spot metering connected to AF point' as being on in his chart).

So what's going on? Is exposure calculated via the Matrix with a extra bit of Spot metering on the AF point?

[aleonx3]

Thanks for replying.

I realise it can do it (by the fact it's in the options lol), where I'm more confused over is having the setting on when in Matrix mode (as circled red with the above chart). This guys an awesome photographer so it's not accidental. He's choosing to show the fact that Matrix is his metering but also has ' C Menu 1 - 5 Link AE and AF Point' as being 'on' (by way of showing 'Spot metering connected to AF point' as being on in his chart).

So what's going on? Is exposure calculated via the Matrix with a extra bit of Spot metering on the AF point?

That setting does not apply if you choose spot metering, it would only apply if you select Matrix metering. In which case, the metered exposure remains the same even if you change your AF point as long as your camera does not move.

[Ex Finn.]

So what's going on? Is exposure calculated via the Matrix with a extra bit of Spot metering on the AF point?

This could be the case, in my limited testing I did not see as big of the difference in exposure as I had expected. But surely the exposure kinda followed my focus selection.

[BruceBanner]

That setting does not apply if you choose spot metering, it would only apply if you select Matrix metering. In which case, the metered exposure remains the same even if you change your AF point as long as your camera does not move.

Wait? None of that makes sense to me...

If you had said "That setting does not apply if you choose Matrix metering, it would only apply if you select Spot metering..." then that woulda made more sense.

Don't you mean that? What you're suggesting is that in this case having Matrix on but having C Menu 1 - 5 Link AE and AF Point as being On somehow overides all metering chosen (matrix, center), which I doubt and instead forced Spot on the AF.

[aleonx3]

Wait? None of that makes sense to me...

If you had said "That setting does not apply if you choose Matrix metering, it would only apply if you select Spot metering..." then that woulda made more sense.

Don't you mean that? What you're suggesting is that in this case having Matrix on but having C Menu 1 - 5 Link AE and AF Point as being On somehow overides all metering chosen (matrix, center), which I doubt and instead forced Spot on the AF.

Yes, I stand corrected.. if you choose spot metering - it will only meter on the spot where you focus on (it will ignore the surrounding). That's why if you left spot metering on by default, you will get over and under exposure quite often.

[BruceBanner]

Yes, I stand corrected.. if you choose spot metering - it will only meter on the spot where you focus on (it will ignore the surrounding). That's why if you left spot metering on by default, you will get over and under exposure quite often.

The question is however, why has the fella (beholder3 with the spreadsheet) have that info selected tho, like why have it on with Matrix. Like this guy is a pro shooter, so I'm thinking he knows something we don't. I might have to test this but I have a feeling it's doing some kinda weird stuff like using Matrix AND a little emphasis of exposure over the AF point, kinda like a hybrid meter...

Gonna have to set up some stable lighting and test...

---------- Post added 03-11-18 at 01:37 PM ----------

This could be the case, in my limited testing I did not see as big of the difference in exposure as I had expected. But surely the exposure kinda followed my focus selection.

I suspect a slight emphasis on the Spot exposure, but still Matrix overall, kinda like a hybrid metering? I felt the same way, it did change the exposure of the frame but not hugely.

[Ex Finn.]

I suspect a slight emphasis on the Spot exposure, but still Matrix overall, kinda like a hybrid metering? I felt the same way, it did change the exposure of the frame but not hugely.

Concur.

[stevebrot]

Gonna have to set up some stable lighting and test...

Always a good idea. This sort of thing is simple to test.

FWIW, this is a feature that I have turned off and generally suggest that others do the same. Every once in awhile we get a help request where exposure is simply strange and finally someone figures out that the camera was set to have exposure follow (biased to) focus. The evaluative (matrix) mode is very good at scene analysis and will generally perform as well or better with the feature turned off.


Steve

[twilhelm]

So... I have this feture turned on. I generally use Matrix, but with the press of a button I’m on spot metering. Which is where this really works nicely.

For instance: I’m shooting a wedding and the camera is on matrix but I want to catch the bride off center of the image. She doesn’t care what the rest of the scene is, as long as she is in focus and properly exposed. Switch to spot metering and focus on her, she will be properly exposed regardless of where she is in the shot.

It does take some serious practice to make it work, but once you have it down you can have some great control on the fly.

[BruceBanner]

So... I have this feture turned on. I generally use Matrix, but with the press of a button I’m on spot metering. Which is where this really works nicely.

For instance: I’m shooting a wedding and the camera is on matrix but I want to catch the bride off center of the image. She doesn’t care what the rest of the scene is, as long as she is in focus and properly exposed. Switch to spot metering and focus on her, she will be properly exposed regardless of where she is in the shot.

It does take some serious practice to make it work, but once you have it down you can have some great control on the fly.

But that's not entirely quite what this is about here.

We understand the difference between Spot and Matrix metering. The above spreadsheet shows a contradiction in settings, he's in Matrix mode but also has enabled Spot metering to follow focus point... but he's still in Matrix mode?! Otherwise he'd have set his metering mode to Spot in the spreadsheet rather than Matrix.

We're trying to ascertain if when turning on Custom Menu 1 - '5 Link AE and AF Point' still has some effect when in other metering modes such as Matrix or Centre, or whether it's simply ignored completely (until like you say you toggle quickly to spot metering.

[BruceBanner]

It does appear to me to be doing a hybrid kinda metering, have a look at the following pics;

First of all forgive the lack of focus or care in regards to content, it's late, I'm tired, I just shot this near my desk to illustrate, and I thought a strong contrasting scene would illustrate best (perhaps not).
The camera was tripodded, and the focus point far right, so that it focused on the lamp (tho u wouldn't notice from the awful focus I got lol).

1st shot (5312), Multi segmented or Matrix as we call it.
2nd shot (5313), Spot metered, but not using the C menu 1 - 5 AE AF Point on at this time. This makes sense, the picture exposed the darker area of the middle of the frame, and the lamp is blown/brighter.
3rd shot (5314), Spot metered but now using the C menu 1 - AE AF Point turned on. Now the lamp is better exposed, remember all these shots were taken with fixed AF far right on the lamp.
4th shot (5316), Matrix metered but still using the C menu 1 - AE AF Point on.

If you compare the 1st and last shot (5312 and 5316) they are similar, but with the spot metering ae af point turned on I feel it better exposed the lamp.

[leekil]

The question is however, why has the fella (beholder3 with the spreadsheet) have that info selected tho, like why have it on with Matrix. Like this guy is a pro shooter, so I'm thinking he knows something we don't. I might have to test this but I have a feeling it's doing some kinda weird stuff like using Matrix AND a little emphasis of exposure over the AF point, kinda like a hybrid meter...

Why didn't you ask him?

---------- Post added 03-11-18 at 11:18 AM ----------

OK, this is all pretty straightforward, though there is little description in the recent Pentax manuals. In the K-3 and K-1 manuals, the description of this setting is "Sets whether to link the exposure value and the AF point in the focusing area". But when you look on the display of the camera when turning this setting on and off, the "Off" setting is described as "Exposure is set separately from the focus point", where as "On" is "Exposure is biased for the focus point." The use of the term "biased" indicates that it might not be a total spot metering on the focus point, but instead it does give more weight to that area when determining the metering.

The K-3 and K-1 manuals are a simpler type of manual than the previous manuals. The only description of the setting is in a table, and there is not additional info available. However, in the older K-1 manual, it has a small section specifically about this feature, and gives more detail. It describes the feature as "Link AE to AF Point during Multi-segment metering".

There is no contradiction here with spot metering vs. matrix metering; you were hung up above because you were relating "spot metering" to the "spot" AF mode. Generally spot metering (or focus) is used to refer to a center-oriented spot, but it doesn't have to be. The "set 1" focus mode is also spot focus, but you can move the spot around.

---------- Post added 03-11-18 at 11:20 AM ----------

P.S. on the K-5 screen display, the setting is described as: AE value is linked [or not linked] to AF Point in multi-segment metering