[stevebrot]

The strength and also weakness of Pentax is it can work will all the legacy lenses going back a long way. The body may be able to communicate and function with the older lenses, but that doesn't mean its perfectly compatible.

If it won't meter very accurately with some of the old lenses, I guess that's a compromise we have to accept.

Anyway there's no comparison with the competition. Nikon, Canon etc. simply won't work with most of Their old legacy lenses.

Kitty,
I does not meter accurately in stop-down (green button) mode even with modern lenses of recent manufacture. That simply does not make sense. It is to the point that I am tempted to pick up a used Luna Pro and work the old-fashioned way.

However, as you point out, at least we can use the old lenses and have some meter function. In addition, it not like we can't use the genuine digital advantage of immediate feedback as to whether things are working right. And (as a last resort), we also have the option of adjusting the curve in post-processing. The available data from the sensor supplies significantly more latitude than was available using film.

Steve

[GearHead]

I used to have the same problem with the old ZX series cameras. I buy and sell a lot and found they all have a problem with over-exposure, but only when using the matrix metering. Using center-weighted (selectable on the ZX-5(n)) or using exposure lock on the ZX-L (places the camera in CW mode), the exposure is much better.

Are the pictures above using matrix metering? Or can matrix metering not be used with the old M lenses?

[stevebrot]

I used to have the same problem with the old ZX series cameras. I buy and sell a lot and found they all have a problem with over-exposure, but only when using the matrix metering. Using center-weighted (selectable on the ZX-5(n)) or using exposure lock on the ZX-L (places the camera in CW mode), the exposure is much better.

Are the pictures above using matrix metering? Or can matrix metering not be used with the old M lenses?

Matrix metering is disabled in "M" mode. CW is default, with spot as an option.

[Lowell Goudge]

Kitty,
I does not meter accurately in stop-down (green button) mode even with modern lenses of recent manufacture. That simply does not make sense. It is to the point that I am tempted to pick up a used Luna Pro and work the old-fashioned way.

Steve

Steve I agree, it makes no sense at all. I guess I would have just accepted the problem and continued on with the lenses as you suggest, by reviewing and adjusting exposure as required, but for one very annoying fact. My *istD does meter correctly, therefore it is not a question that it can't be done, only a question of why was it not recognized.

Remember, although not really pushed as a marketing point with the *istD family, the KXXX family of DSLRs are marketed explicitly as being able to use any of the 23 million lenses made by pentax. OOPS!

As I understand it, the real issue is the focusing screen and the way light reflects off the microlenses in the focusing screen to the meter, that are the cause of the problem. People have changed focusing screens and claimed better performance in manual metering at the expense of metering on AE lenses. (I suspect due to the software correcting for this in AE mode)

If this is truely the case, why can't pentax offer users one of the following options.

1) either a revised viewing screen (perhaps not as bright) that will meter correctly (along with correction for AE lenses in software) or

2) the ability to input minimum and maximum apature for lenses where the camera senses no AE function available, and then control the apature as it does in AE mode.

either of these can work, and my preference is for the second, because it would also allow for P-TTL flash with manual apature lenses.

While I am happy that I don't need to replace all of my old lenses like many nikon and cannon owners have done, I wish they could be used just a little more spontaneously. I can't ask people to re-enact the photo of the century because my light meter was wrong, when it should not have been.

[Lowell Goudge]

I used to have the same problem with the old ZX series cameras. I buy and sell a lot and found they all have a problem with over-exposure, but only when using the matrix metering. Using center-weighted (selectable on the ZX-5(n)) or using exposure lock on the ZX-L (places the camera in CW mode), the exposure is much better.

Are the pictures above using matrix metering? Or can matrix metering not be used with the old M lenses?

Matrix metering needed the apature information to work, and is disabled on non AE lenses on all DSLRs.

Issues exist with spot metering defintiely (this is what I rely on most)

[Sailor]

Most people seem to have more trouble with apertures over 5.6 overexposing here is an example of a shot from my m135 3.5 taken at f5.6 f8 f11 and f16. I have more if you'd like to see..Bob

Exactly my experience with my very early K10D (my DS2 handles M lenses perfectly). I'm betting later versions of the K10D (and I assume the K20D, as well) don't experience this problem.

Jer

[robert]

I did some further testing with my takumar and m lenses. I put them on my old istds and I have to admit the exposure was much more consistant and accurate than with my k10d. Maybe I'll just keep my ds to use with the older lenses...Bob

[Stratman]

I just did a test with my K110D Vs. My K10D, both at ISO 200, spot metering, same lens, Ricconar 55 MM F 2.2 K110D is MUCH better with "green button" Metering.

First 7 are the K110D
@ F 2.2


@ F 2.8


@ F 4


@ F 5.6


@ F 8


@ F 11


@ F 16



Now the K10D same settings and lens

@ F 2.2


@ F 2.8


@ F 4


@ F 5.6


@ F 8


@ F 11


@ F 16

[stevebrot]

I just did a test with my K110D Vs. My K10D, both at ISO 200, spot metering, same lens, Ricconar 55 MM F 2.2 K110D is MUCH better with "green button" Metering.

Hmmmm...Looks familiar...

[madhurvyas]

Metering with M & M42 lenses is bit tricky, I dont have M lens but few M42 are there which I use mostly.
I'm planing to take some time & do some strict metering test, then mark the EV componsation on the lenses using marker pen, Whenever I will set the aperture I can adjust the EV accordingly.
Any way I use the manual lenses where I have lot of time to adjust, so this way it would be easy for me to do the correction.

I recently changed the focusing screen, after that it seems to me that metering has improved.

[morfic]

If it makes you feel any better, your K10D acts just as well as the Canon 30D i just sold, and from what i hear all other Canon's do the same, i like your K110D samples though.
Makes me wonder now how the K20D that hopefully is now on its way will do that, if it acts like your K10D, i'll feel right at home, if it acts like your K110D, i need to learn to not automatically compensate as i stop down

[jeffkrol]

I just did a test with my K110D Vs. My K10D, both at ISO 200, spot metering, same lens, Ricconar 55 MM F 2.2 K110D is MUCH better with "green button" Metering.

Hmmm.. you win the prize.. those shots w/ the K110 are the first I saw w/ ANY K series camera
that have decent green button metering w/ a manual (or any lens) lens....
Actually that is more of a mystery than the K10's screwed up manual metering..

[jeffkrol]

Exactly my experience with my very early K10D (my DS2 handles M lenses perfectly). I'm betting later versions of the K10D (and I assume the K20D, as well) don't experience this problem.

Jer

Bet they do....

[morfic]

One thing i always meant to test on the 30D and never did: how do K10D meter in stop down metering when using spot instead of average or evaluative/matrix metering.
I once read the theory the closing iris affects how the outer zones meter compared to the still bright center. Always meant to test it, seeing how this is a hot topic here, if i encounter the issue on the K20D as well, i may have to test it. Right now all i can wonder while the cam is in a UPS truck or plane somewhere.

Hope this helps any.

[Stratman]

I am pretty sure you can only meter in spot metering in "M" mode