I need some expert help on the K10D and manual lenses

<p>I finally bought me a second dSLR system after I had the chance to play around with Pentax cameras last year. I wanted a versatile platform for my manual focus gear with built-in image stabilization and now I have my own second-hand K10D.<br /><br />I have quite a few K-mount lenses so I could do a lot of trial-and-error. Of course I use the custom function to allow the usage of lenses without an "A" setting. But I noticed a few things and I would like some input on if this is normal, or if I am missing anything completely, or if my camera is at fault.</p>

<ol>

<li>The camera does NEVER adjust exposure when I stop down a lens. It meters at full aperture and if I turn the aperture ring to a smaller f-stop, the shutter speed stays the same and the resulting image is underexposed. Huh?</li>

<li>With <em>many</em> lenses (especially Chinon and Agfa, but also some Cosina) the stopping down does not work. When using the optical preview it clicks, but the aperture is not stopped down at all. When taking a picture I can see the aperture closing, but this does not happen at the time of exposure. All pictures are actually shot wide open. Please note that these lenses work fine on regular Pentax-K cameras. It is normal that not all K-mount lenses are fully compatible on Pentax dSLRs?</li>

<li>I use the manual focus lenses in Av mode. But I can never change the exposure compensation. Turning the correct dial does not have any effect. With an AF lens mounted it works fine, but why can't I adjust the EC when I use a manual lens?</li>

</ol>

<p><br />Thanks for your help!</p>

<p>That camera metering problem might be fixed with an adjustment in the "Custom Settings" menu; so it is with the K200D. If you can find a similar adjustment on the K10D, that might answer most of those aperture-related problems. The camera metering adjustment has a name like, "Metering: Accept aperture ring", or something like that.</p>

<p>Try scrolling down about halfway through this thread: http://www.photo.net/pentax-camera-forum/00SUOg There will be a specific list showing how I reset the K200D to deal with manual lenses; maybe some of those setting ideas can help you with your equipment.</p>

<p>Or, try this link from my blog for the same info in a different format: http://www.agxphoto.com/search?updated-max=2009-03-04T04%3A55%3A00-05%3A00&max-results=1 I don't have any directions specific to the K10D, so if you figure it out, it might help somebody if you post back a sentence or two on how you figured it out. </p>

<p>Good luck. J.</p>

<p> </p>

<p>When turning the ring, you have to press the Green Button to meter (next to the shutter).</p>

<p>Av mode will not work at all because in Av mode the camera only meters wide-open but stops down the aperture to the ring setting when you trip the shutter.</p>

<p>So the only reliable mode is M mode. Put it in M, press the green button to take a reading at your preferred aperture.</p>

<p>Caveat: the metering is wrong. At aperture settings from 1.4 to 2.8 (roughly) it under-exposes by two stops. So after pressing the green button, apply a +2 stop correction.</p>

<p>From 4.0 to 5.6, add +1 stop.</p>

<p>From 8 to 11, usually it's spot on.</p>

<p>Below that, it starts over-exposing.</p>

<p>This is not a problem unique to the K10D, because modern SLR focus screens and metering systems are optimized for slow consumer zooms. The "A" lenses avoid this because they can tell the camera what their maximum aperture is, and the camera can compensate.</p>

<p>Thank you both very much!</p>

<p>This is very interesting and quite disappointing for me to hear. I have heard so much about the wonderful backwards-compatibility of Pentax that I expected too much I guess. I wanted this Pentax camera to be my fun system for the use with fast, older prime lenses, and not buy a complete autofocus kit again. But if MF lens usage is so uncomfortable and slow, then I guess I will sell the K10D again. It is very sad to hear that Pentax crippled their dSLRs like Nikon.</p>

<p>I can use a lot of adapted manual focus gear on my Canon camera where the internal light meter works fine with aperture-priority and is pretty accurate (within ½ stop) with stop-down metering. But I was blown away by Pentax' built-in SR, so I had high hopes as a prime lens shooter.</p>

<p>But still it does not explain why so many of my lenses are not correctly stopped down. Can anybody confirm this that third-party gear is less compatible?</p>

hi

 

you said you use the lenses in Av mode.

I think that unless the lens has an "A" setting (ie, like the pentax A lenses) then you must set the camera to M.

Then, when you set the desired aperture, you press the green button, you actually then hear the camera stopping down the lens for a bit, to

meter, and then the shutter speed would change.

 

hope this helps

 

christos

<p>Bueh B.,<br>

Whoa! I don't think you have gotten very good or accurate information here, partially because you have not provided much detail about your lenses, and the respondents have had to make some assumptions. Your conclusion is basically wrong. Your Pentax DSLR is very compatible with just about any K-mount lens made during the past 40 years. I've used three DSLR models over the past 4 years with dozens of older manual focus lenses and all have provided reasonable exposure.</p>

<p>All K-mount manual focus lenses are not the same. Some are A-type lenses meaning that you have auto-exposure capability. The aperture rings locks in the A position. The lens can communicate this information to the DSLR which in turn uses it metering system to set proper exposure. You must activate in the custom menu the "use aperture ring" function. Then you can use the AV mode or the TV mode and control aperture using the dials.</p>

<p>Please share one or two examples of what particular lens you are testing with. You may be using a non-automatic lens. These are commonly the Pentax M-lens or a Pentax K-lens. These have no auto capability but with some practice and savvy they work great. Set the camera to M mode, press the green button and the camera returns the suggested EV. You can manipulate the shutter speed with a dial, you can move the aperture ring for DOF control. It is good old stop down metering.</p>

<p>You may need to adjust an EV variation off what the camera recommends. Depends on how accurate your camera meter is, personal taste, backlighting etc. But as a photographer this should not stop you from taking a good shot. With the K10D I tended to overexpose by a half stop but there was plenty of variation to keep me thinking. i like that. Most of my shooting includes auto-bracketing by a half stop on either side. This works with old lenses too.</p>

<p>You should also be able to obtain visual confirmation (the red light flash) when your manual lens has reached focus. Check to custom functions. Do you have a users manual?</p>

<p>Once you figure this stuff out I'm sure you will enjoy the camera a lot.</p>

<p>ME</p>

<p>The K10D mount is considered 'crippled.' It really wants lenses that kick data back to the camera body to use any sort of AE mode. That said, I use all kinds of manual lenses on my K10's, even screw mount lenses with an adapter. M42 lenses obviously won't stop down automatically, so I have to flip the auto/manual switch on the lens to manual unless I'm just shooting wide open.</p>

<p>As far as your Chinon, Agfa, and Cosina lenses, I guess anything is possible with 3rd party lenses. Some Ricoh mount lenses have a pin that will jam into the Pentax AF drive hole on the camera mount. Others have a flange that will conflict with the body and require grinding or removal to mount the lens.</p>

<p>Are you are using the optical or digital preview? I typically use a digital preview with histogram for checking exposures, but I'm curious about you seeing the lens start to stop down but open back up by the time the shutter is open. Is the behavior the same when releasing the shutter, hitting the green button and DOF preview? This sounds like some sort of failure either in the lens or the camera. Since it is only on 3rd party lenses causing you problems, I wonder if the pins are too short or something. You wouldn't be the first to have some sort of break down in that system, I've seen it on a old SMC M 50mm that the pin was just plain worn down too far. It is, however, just as possible that the camera side of the linkage is malfunctioning.</p>

<p>I've also seen repeated reports of the metering being off when using pre-A series lenses, but mine have always been spot on. Call me weird.</p>

<p>Thanks for all your comments! I am a newbie in regards to Pentax digital, but I have lots of experience with Canon dSLRs and Nikon film cameras (plus several Mamiya medium format systems and dozens of "classic" cameras). I am still surprised that speed of operation and meter accuracy is so much better with the EOS system when I adapt M42 or PK gear in comparison to a "native" Pentax dSLR (I do have an original Pentax M42-PK adapter, by the way). Poor backwards-compatibility was the main reason for me to abandon Nikon and choose Canon when I went digital. With my EOS 20D I can use all adapted lenses in Av with full exposure-compensation control and excellent e-TTL flash support. The only drawback is the manual stop-down operation (and the lack of SR/IS/VR).</p>

<p>For me, 35mm and digital is all about speed and convenience. I don't want to fiddle with "M" and "the green button" to guestimate each time I take a picture. And I am definitively not ready to use my Sekonic incident meter when I shoot with a 21st century camera!</p>

<p>To answer your questions: Yes, I have the user's manual and read it. I get focus lock information with the manual focus lenses although it is not that accurate. My manual lenses all lack an "A" position, unfortunately (they are from before-1982 or so). I use optical (DOF) preview -- for digital preview I can just take a picture. I don't know if the shutter opens before or after the aperture is stopped down and opened up, but with the "issues" lenses the aperture-closing is not in sync with the shutter opening. The same applies to "the green button" usage. Worn-out lens mechanics could be a possibility, but with so many lenses...? If I have the time tomorrow I will make a list which lenses work fine and which ones have this aperture-operation issues. My K10D looks pretty nice and according to PhotoME the shutter count is less than 9000, so I guess I would be equally strange that the camera is worn out. As Orlando said, with my fast lenses the camera's meter is about 2 stops off, so count yourself lucky, Matthews!</p>

<p>Replacing the focusing screen with the LL-60 from the ist-DS has been known to reduce (but not eliminate) the metering issues.</p>

<p>In my personal experience with an EOS 350D, at large apertures (f/2 on a Jupiter-9) it also does tend to under-expose. So I don't consider this a problem exclusive to Pentax. Olympus users also report similar issues when using OM lenses on 4/3 bodies.</p>

<p>In my experience if you're at around f/4 to f/5.6 which is generally the sweet spot anyway, the metering errors are acceptable (within 1/2 stop or so). I usually chimp the histogram as well when using M or screw/M42 lenses.</p>

<p>The reason Nikon (higher-end) bodies meter perfectly with legacy Nikon glass is because they have the aperture-coupling lug and can read off the mechanical aperture.</p>

<p>Certain Pentax film cameras do have this coupling lug. It's a pity that Pentax did not put this lug in at least the K10D / K20D which are their higher-end cameras as the MZ-5 and friends do have it.</p>

<p>I think Pentax did the minimum necessary to claim "compatibility with the 20 Million Pentax lenses out there" --- aperture stop-down works, and metering works (after a fashion). Just remember to apply your offsets...</p>

<p>I use my K10D mostly with all my manual focus lenses. And I rarely use anything other than M mode and Green button. Works great. At times, I do have to change exposure by one stop, but thats not very often.<br>

Please consider K10D (and manual focus lenses) as a very good choice you have made. Don't regret ;-)</p>

<p>I have a K10D and several M42 and old K mount lenses. I am very happy with the functionality and results of the combination.<br>

They are manual lenses and operating in a manual fashion is necessary and well worth it.</p>

<p>You enable the aperture ring, then put the camera in M mode, select your aperture, hit the green button for the camera to meter and adjust shutter speed for correct exposure. It is quick and easy. Since you are selecting your aperture, you are in reality operating in AV mode. Metering is accurate if you do not go smaller than about f/11 or so. Although TTL flash is not usable, you can get a low-cost older flash having its own auto sensor but no P-TTL, like the AF 280T, which will provide very good exposure.</p>

<p>Sounds like Canon has developed a good system to resurrect use of their old MF lenses on their DSLRs with an adaptor. I do not know if that applied to their film AF SLR bodies.</p>

<p>With Pentax, most of the film AF bodies accept the old K mount MF lenses with no adjustments necessary at all. Even TTL flash is usable. On a DSLR, you also get the advantage of having SR with these old lenses. I pushed that feature to the limit recently, just to see how much I could get away with- shooting my 30 year-old K-mount Pentax "M" 135mm (think 205mm on digital) f/3.5 wide open in very dim lighting, just using ISO 100 at 1-1/15 sec on my K200D. I got better than 50% shots clear at this extreme setting! I could have gone to a higher ISO for a greater success rate, but I just wanted to see if I could still shoot ISO 100 under such an extreme situation. This lens is from about 1978!</p><div></div>

<p>Sorry, I meant 1/15 sec!! So this was giving me about 3-4 stops over normal, hand-held.</p>

<p>I am happy to know that my camera seems to be okay. I was really surprised by the awkward operation of my K-mount lenses (except for two that feature an "A" aperture setting). Fortunately, it seems that most of my lenses stop down correctly when used in "M" -- although none of my 135mm lenses do and with some lenses there seem to be irregularities.</p>

<blockquote>

<p>I use my K10D mostly with all my manual focus lenses. [...] At times, I do have to change exposure by one stop, but thats not very often.</p>

</blockquote>

<p>With my fast glass (i.e., f/1.2-2.8) I have to dial in <em>a lot</em> of exposure compensation, which considerably slows down shooting these old lenses.</p>

<blockquote>

<p>I have a K10D and several M42 and old K mount lenses. I am very happy with the functionality and results of the combination.</p>

</blockquote>

<p>Good for you, I still consider this slow operation a dealbreaker as I work fast and often under changing lighting. The inability to use a P-TTL flash with these old lenses is also not great.</p>

<blockquote>

<p>Since you are selecting your aperture, you are in reality operating in AV mode.</p>

</blockquote>

<p>No, I am not. Maybe you should read about what aperture-priority AE mode is. The K10D with manual lenses is not adjusting the shutter speed and the "green button" metering is very inaccurate, resulting in me having to set the "correct" exposure compensation for pretty much each and every shot.</p>

<blockquote>

<p>Sounds like Canon has developed a good system to resurrect use of their old MF lenses on their DSLRs with an adaptor. I do not know if that applied to their film AF SLR bodies.</p>

</blockquote>

<p>No, you cannot use manual focus Canon FD/FL stuff at all on any EOS cameras due to the short lens register. However, you can adapt virtually all Olympus OM, Nikon F, Leica R, Pentax K and M42 lenses (plus various medium format gear). Even on full-frame and film cameras. Only with PK it is a bit tricky on full-frame camera since the aperture pin has to be removed on some lenses because it goes to far into the mirror box (this is mostly a non-issue in APS-C). As I said, Av mode fully works and the camera adjusts shutter speeds on-the-fly and accepts EC. Even e-TTL flash (and flash exposure compensation) works great. The biggest drawback is the manual stopping down of a lens, resulting in a darker viewfinder image.</p>

<p>Hi<br>

I also use "K" and M lenses a lot and find it easy and very rewarding. I cannot answer for your non-Pentax lenses, but for the "K" and M lenses:<br>

1. As has been pointed out you must use M mode and the green button; or M mode and activate the DOF preview button and adjust according to the light meter bar that apears.<br>

2. If you want to shoot wide open you can use Av mode<br>

3. Change the focus screen to LL-60 to get accurate exposure at all apertures. Or change to a split prism screen and get better focus accuracy than using the AF confirmation.....you will still have exposure inaccuracy, but I get used to this very quickly depending which lens I am using.<br>

4. Use the histogram!<br>

5. M42 lenses meter just fine in Av mode.</p>

<p>You mentioned your shooting style in your last post, and to be honest if I had that shooting style I would not consider using an old lens...you wont be able to use them as quickly as a modern lens.</p>

<blockquote>

<p>If you want to shoot wide open you can use Av mode</p>

</blockquote>

<p>Not if I need exposure compensation!</p>

<blockquote>

<p>Change the focus screen to LL-60 to get accurate exposure at all apertures. Or change to a split prism screen and get better focus accuracy than using the AF confirmation</p>

</blockquote>

<p>What's the drawback of this? Will autofocus lenses still work fine or will this turn the camera into manual focus-only dSLR?</p>

<blockquote>

<p>M42 lenses meter just fine in Av mode.</p>

</blockquote>

<p>Not if I need exposure compensation!</p>

<p>All in all, I still like the K10D. It's a very powerful camera with many excellent features that I miss on my EOS camera. Some other things bug me, though, like the "Fn" button instead of dedicated buttons for WB or ISO or the lack of a real thumb wheel, for example. And deleting pics in-camera is way slower than with the old EOS 20D. But if Pentax/Samsung would offer a full-frame body I would abandon Canon in a heartbeat!</p>