[GoremanX]

I'm a little confused about the AF Adjustment feature in my K-7. There's an "Apply All" field and an "Apply One" field, each of which goes from -10 to +10. I understand most of this; "Apply All" applies to every lens, and "Apply One" applies to the specific lens currently attached.

However, I don't understand if the values affect each other. For example, if I set "Apply All" to -5, and I set "Apply One" with my DA* 50-135mm to -3, does that make a total of -8 when I'm using that lens? Or does the camera ignore the "Apply All" setting and just use the -3 value?

[Nass]

It's clearly explained in the manual on page 122.

Any apply all value, if set, takes precidence

[aerodave]

I'm not sure that's exactly what it says. Then again, I'm not sure what it *does* mean. Here's what the manual says:

Even when an adjustment has been saved using [Apply One], if you press the OK button with [Apply All] selected in Step 3, the [Apply All] value is used instead of the [Apply One] value.

It doesn't say what happens if you have values set in both fields and press OK with the [Apply One] selected. What does it do with the [Apply All] value then? Are they additive, or is just the "One" applied?

[Rondec]

I had assumed that they were additive, one applied to all lenses, the other added to one particular lens.

[Russell-Evans]

the [Apply All] value is used instead of the [Apply One] value.

I don't see why there is confusion?

Thank you
Russell

[RBellavance]

I don't see why there is confusion?

Well, strictly speaking, the manual does not say what happens with the "Apply All" value when you select "Apply One", it only talks about the reverse. And I remember from my logics courses that A => B does not necessarily mean B => A...

[aerodave]

After a little semi-scientific testing, it seems to me that choosing the "Apply One" value for a lens causes the camera to completely ignore the "Apply All" value. They are not additive.

I used an FA50 (since it's my only lens that I know doesn't need AF adjustment) and a focus test chart. If I dial -10 on "Apply All" and press OK with "All" selected, it back focuses. If I do the same thing with +10, it front focuses. This is with the "Apply One" field set to 0 (or any other value for that matter). No surprises there based on what the manual says.

If I then change nothing else, and select the "Apply One" field, press OK once to make the value editable and again to save it at 0, then take a picture, the focus is accurate. The results are the same whether the "Apply All" setting is -10 or +10. Similarly, adding extreme values of -10 and +10 have the familiar front- and back-focusing effects regardless of what value is in the other field. The more I experiment with it, the more it's obvious that the camera only uses one of the values: the one that was selected.

I had always assumed that the numbers were additive. That is, the "All" value set the baseline, and the "One" value provided on offset from that for each lens. It appears that it doesn't work that way at all. "Apply All" is more like the default value for any new lens, and can be overridden by selecting a value in the "Apply One" field.

[Russell-Evans]

Well, strictly speaking, the manual does not say what happens with the "Apply All" value when you select "Apply One", it only talks about the reverse. And I remember from my logics courses that A => B does not necessarily mean B => A...

Be practical, how would you tell if you set "Apply One" before or after "Apply All" after you did it? Both conditions would look the same as far as the interface goes. If it was the case that "Apply All" acted differently in the two cases, then wouldn't there have to be an indication in the interface to make it workable for the user so that they would know what was going on a month or two after they set it up? I personally wouldn't be able to remember what I did after three minutes.

If you could set "Apply One" and have the setting be applied to "Apply All", the first time you changed "Apply All", you would have to go back in and reapply all twenty "Apply One" settings as we know that setting "Apply All" means the "Apply All" setting is used when this happens. Sound practical? Something you want to do? Something anyone would want to do? Does it make sense for the Pentax engineers to design it like this?

I think the logic is more like C=A+B and therefore C=B+A, but I don't usually practice logic this early in the morning. :ugh:

Thank you
Russell

[RBellavance]

Be practical, how would you tell if you set "Apply One" before or after "Apply All" after you did it? Both conditions would look the same as far as the interface goes. If it was the case that "Apply All" acted differently in the two cases, then wouldn't there have to be an indication in the interface to make it workable for the user so that they would know what was going on a month or two after they set it up? I personally wouldn't be able to remember what I did after three minutes.

Oh, I was not arguing that both settings were indeed additive. I was just pointing out how I thought some people could be confused.

[aerodave]

If you could set "Apply One" and have the setting be applied to "Apply All", the first time you changed "Apply All", you would have to go back in and reapply all twenty "Apply One" settings as we know that setting "Apply All" means the "Apply All" setting is used when this happens. Sound practical? Something you want to do? Something anyone would want to do? Does it make sense for the Pentax engineers to design it like this?

Well, what actually happens is that the adjustment type that was chosen for each lens is remembered in the interface. If the last AF adjustment you saved for a lens was the "Apply One" setting, the arrow on the interface will be parked on "Apply One" when you go back in later—even after using other lenses. If the last adjustment you saved for a lens was confirming the "Apply All" value, thereby ignoring the "Apply One" setting if it exists, then the interface arrow will be back on "Apply All" when you return to the dialog for that lens at any point in the future.

That's how you'd know which value you set last for that particular lens. You can have the camera remember an "Apply One" value that never gets used for that lens, even though it's always retained. The decision to use the default value or the individual value for that lens is retained in the camera's memory.

[RBellavance]

That's how you'd know which value you set last for that particular lens. You can have the camera remember an "Apply One" value that never gets used for that lens, even though it's always retained. The decision to use the default value or the individual value for that lens is retained in the camera's memory.

Very interesting ! I did not realize the "Apply All / Apply One" choice was on a per-lens basis. I just tested it and it is indeed.

So the adjustements are not additive, but one can choose whether to use the "All" or the "One" setting for each lens.

[GoremanX]

wow, I thought it was a simple enough question, and it turned into this.

Fascinating...

Thanks for clearing that up! Now I need to come up with a better focusing chart.

[Russell-Evans]

That's how you'd know which value you set last for that particular lens.

I never noticed that or connected the two. Thank you


Thank you
Russell