[Stratman]

Both my M lenses prefer f/5.6 to f/8 for metering. Don't use a stop specified by anyone else - you don't have the same lens. f/4 probably works for a 50/1.7, but it sure doesn't work for a 100/4 or a 400/5.6. Do the aperture, green button, aperture, green button all the way across the aperture list with the camera on a tripod or bean bag, looking at something average. Then run the histograms and you will find the sweet stop. Use that to meter.

I was just going by my experiences with my K10D, seems, with faster lenses, like 1.4, 2, 2.8, ..F4 is the magic number to get a good exposure. I really have not tried with any of my slower manual lenses, will have to check out the Vivitar 400 MM with the green button, and see where the sweet spot is.

[Canada_Rockies]

I was just going by my experiences with my K10D, seems, with faster lenses, like 1.4, 2, 2.8, ..F4 is the magic number to get a good exposure. I really have not tried with any of my slower manual lenses, will have to check out the Vivitar 400 MM with the green button, and see where the sweet spot is.

It's probably right around the same f/8 as my Pentax M 400/5.6. It meters (with the regular screen!) well at f/8 through f/11. The macro also meters well at f/8, so I just went back to f/8 and be there. I might not have to do it with the LL-60 screen. The shutter speed progressioin matched the aperture settings stop for stop, which is an encouraging sign.

[fwcetus]

I answered the unwritten question. You are indeed 100% correct. They should not expose badly. But they do.

Understood. And, I was not really "correcting" you, but merely trying to state what ~should~ be true about K-mount backward compatibility. And, your answer was more ~useful~ than mine anyway - my answer was just the "grumbley" one - <g>. So, no "Mea Culpa" needed at all, Canada. ;-)

[Timarete]

Pulling the on/off switch into optical preview position stops the lens down and turns on the meter. With the K10 and K20, an exposure scale shows in the viewfinder and the top LCD. You do match needle metering, basically. I prefer it. It also gets around things when you know the meter is going to be underexposing because everything is white. You just add the appropriate set of bars. Think snow. Meter the snow, add two stops of exposure on the scale, and you are set. You don't have to green button, then open up two stops. Try it. You might like it. You might hate it, too, but that's ok by me. Different strokes.

Thank you for these very clear instructions. I must have a setting wrong somewhere. When I pull the on/off switch to the preview position, it actives Live View, and no scale appears anywhere--neither in the viewfinder nor on the top LCD.

[Canada_Rockies]

You need to change the preview setting to [Optical] in the [Custom] menu [Preview Method]. This will turn off live view (K20D only) and/or the preview on the LCD on the back of the camera. The K200 and K100 will display a number at the bottom right of the view screen. Under -3.0 to 0.0 to 3.0 (overy)

[Timarete]

You need to change the preview setting to [Optical] in the [Custom] menu [Preview Method]. This will turn off live view (K20D only) and/or the preview on the LCD on the back of the camera. The K200 and K100 will display a number at the bottom right of the view screen. Under -3.0 to 0.0 to 3.0 (overy)

Ah, it was that custom setting that I was missing. Now it works as you described. I do get a different shutter speed with this method. Many thanks for taking the time to explain it all!

[Canada_Rockies]

Ah, it was that custom setting that I was missing. Now it works as you described. I do get a different shutter speed with this method. Many thanks for taking the time to explain it all!

That's what we are all on this forum for. I automatically went for the scale exposure because it thinks the way all my other Pentaxes thought. I had the camera nearly a year until I twigged (on these forums) that pressing the green button set the shutter speed.

[chhayanat]

The short answer is "Yes". Both the k20d and k10d have metering issues with non - A lenses. I have just received an LL-60 screen (meant for *istD) and it seems to be better with the manual lenses. It will be a week or so before I've run all the tests, but it is looking pretty good right now. Depending on the aperture you set with the stock focusing screen, the non-A lens might over or under expose.
The other option is with the on/off switch last position set to optical preview, holding the dof position will bring up the exposure scale in your viewfinder. Turning the front e-dial while watching will allow you to set your preferred aperture and shutter speed.

Just bought a GX20 (K20D) bundled with the 12-24mm Schneider (read Pentax DA) for lowish price, USD666. They refused to sell just the body.

SMCP-M lenses overexposing by two stops. Good for flying birds with 400mm but an impediment with other M lenses. At present using exposure scale to compensate. Will do a more thorough check with other M lenses.

If the LL-60 screen is said to be more accurate with SMCP-M lenses, does it continue to monitor DA lenses accurately. I find that Pentax has a new LL-80 screen now. What is known, if anything, about its properties with SMCP-M lenses?

Is the LL-60 screen user installable on the K20D? if yes, is there any guide for users for this work? The GX20 should be similar and I will start looking for a screen.
Best wishes

[Marc Sabatella]

"Lowish?" $666 for *either* of those items would be a fine deal. $666 for both is *incredible*.

[dlacouture]

chhayanat : yes, the LL60 can be easily installed by the average Joe... Look for videos on YouTube...

And as for DA lenses, I find that my k20 exposes waaaaay better with my FA & DA lenses than with the original screen...
I don't know about the LL80, but I'd bet it's the same as the original screen...

[chhayanat]

"Lowish?" $666 for *either* of those items would be a fine deal. $666 for both is *incredible*.

As I already have a K200D with a 16-45mm DA ($828 with 4GB Sandisk Ultra II, 5-in one reader and lithium batteries from Adorama+Amazon), and two MX bodies, the GX20 was, frankly a bit of an overkill, but the price was compelling. If you find anyone travelling to Romania please ask them to visit F64 Studio - Echipamente fotografice, aparate foto compacte si digitale, obiective, accesorii. It's still on sale there. Possibly the only consumer electronics item actually cheaper than elsewhere.

Which was why, after experiencing overexposure with M lenses, and having forgotten prior posts in Pentaxforums, I thought the GX20 I had been sold was a defective piece.

Although somewhat off-topic, there is no harm in writing that the K200D is an excellent camera and the single wheel is a non-issue for users of manual Pentax lenses. I have transferred functionality for M lenses to the rear wheel in the GX20 to match the K200D. The K200D does almost everything right, like the MX did for the manual bodies. The GX20 is essentially a backup for the K200D, as DSLRs are unlikely to have the longevity of the MX bodies (I once got a written reprimand for poor upkeep from a repair guru who serviced one of the MXs).
It was a gross error for Pentax to concentrate on the KM while writing off the K200D.

[Canada_Rockies]

chhayanat : yes, the LL60 can be easily installed by the average Joe... Look for videos on YouTube...

And as for DA lenses, I find that my k20 exposes waaaaay better with my FA & DA lenses than with the original screen...
I don't know about the LL80, but I'd bet it's the same as the original screen...

Yes, I just replaced the LL-80 with the LL-60. All it has over the original screen is the grid lines that my crooked eyes need to keep things straight. If you buy your LL-60 from a reliable vendor (such as Japan Camera Store) there are all the tools and instructions included. It's very easy to do, and I can assure you that it is even more easy to get dust in the viewing system.

I have tested the LL-60, and the metering is spot on for every lens I have. M, A, FA, DA. Makes no difference with the newer lenses. I cannot say by my tests that it meters better with my DA lenses, but it definitely meters accurately. I used the histograms and there is almost no movement across the scale with varying apertures. Any difference I can put down to my own testing regimen, which is "point it, shoot it, look at histogram." This is not exactly a rigorous testing regimen, but I have no exposure errors.

This came to a head while I was attempting to use the AF 1.7X with the M 400/5.6. Nothing worked right except wide open. Now I can set any aperture, and get the correct shutter speed. Unfortunately, the green button does not work. The old lens is just too slow with the stop down mechanism for the brief period that the green button holds it open. I therefor use the other system, which matches my too many years with manual exposure cameras - scale exposure with the optical depth of field preview.

[Squier]

Thats a nice report on the LL-60, because its still on my purchase list along witht the split prism thats in the post.

[5teve]

I have tested the LL-60, and the metering is spot on for every lens I have. M, A, FA, DA. Makes no difference with the newer lenses. I cannot say by my tests that it meters better with my DA lenses, but it definitely meters accurately. I used the histograms and there is almost no movement across the scale with varying apertures. Any difference I can put down to my own testing regimen, which is "point it, shoot it, look at histogram." This is not exactly a rigorous testing regimen, but I have no exposure errors.

This came to a head while I was attempting to use the AF 1.7X with the M 400/5.6. Nothing worked right except wide open. Now I can set any aperture, and get the correct shutter speed. Unfortunately, the green button does not work. The old lens is just too slow with the stop down mechanism for the brief period that the green button holds it open. I therefor use the other system, which matches my too many years with manual exposure cameras - scale exposure with the optical depth of field preview.

Hi Canada

I had quite high hopes for your method, so eagerly rushed home tonight and tried it. if im not mistaken its using the optical preview while holding the preview lever? this shuts the lens down, shows the meter and with your fifth hand allows you to set the exposure correctly by altering the shutter?

well comparing to the green button im not getting much in the way of differing results in controlled condition, it may well be different in the real world so i'll try it and time will tell.

interesting that you say about the lens stopping down too slowly and the metering happening too quickly.. its a thought that crossed my mind, however according to the manual all manual lens default the camera to centre weighted metering with the option to choose spot. therefore as the exposure would be calculated behind my diagonally split prism by the camera the prism blacking out would cause over exposure.

all well and good.. except i get a variation of over and under exposure. its even been happing in real use situation on my sigma lens's!

im sure its something that can be fixed via firmware... isnt it?

Thanks

Steve

[GeneV]

Well, actually, the ~correct~ answer to the question "Should K20D overexpose with M lenses?" is ~NO~!

Unfortunately, due to the crippled K-mount, the answer to the question "Does the K20D overexpose with M lenses (or K lenses)?" is indeed YES.

:-(

Took the words from my mouth. My single biggest complaint because it turns most of a 30 year lens collection into a PITA to use. IMO, all other issues are niggling compared to the lobotomized K-mount.