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Forum: Pentax Lens Articles
01-02-2016, 08:18 PM
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I've been through the various posts on this subject a number of times, but perhaps I need to read through them again. What I have found is this:
1. A Pentax OEM adapter is the best way to go if you can find one (just bought one on e-bay for $35, including shipping). I can install and remove it with my fingers. I had a Fotodiox and it nearly ruined a lens.
2. You can use the green button with K-mount lenses ONLY; I have been unsuccessful using it with M-42 mount lenses. Nothing happens.
3. The screw-mount (M-42) lens you're using has to be set to manual if it has a "manual"/"auto" setting, in order for the light meter to read it when you change the aperture.
4. On the K-50 (and others Pentax bodies with similar settings), you can use the TAV setting quite effectively with M-42 mount lenses. First, set it so it will only choose between ISO 100 and ISO 200 (or higher if you like). Then, when you choose the aperture on your M-42 lens, the camera will automatically choose shutter speed. This will produce consistent results—if you have limited the range of the ISO.
5. Because of #4 above, using M-42 mount lenses might be seen as an easier option than using a K-mount lens and having to remember to push the green button every time.
6. I haven't experimented with it yet, but I imagine AV mode would work with M-42 mounts too, probably easier than the TAV mode. I haven't seen either of these options mentioned by others. The Pentax/Ricoh website seems to indicate that the green button should work with M-42 mount lenses. It doesn't on my K-50.
I hope this is not redundant information. I'm just learning about Pentax cameras and loving every minute of the learning experience.
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Forum: Pentax SLR Lens Discussion
12-08-2015, 12:50 AM
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Great pictures, Sagitta. Thanks for sharing them. I can't wait to get my Pentax K-50 on Thursday and try out my legacy lenses.
Regarding Pinholecam's observations: Thanks for the information. And you're right; the f/1.4 is barely any bigger than the f/1.4 or the f/2.0. And, even if the f/1.4 were found to be a little soft wide open (some people's observation), one can save that aperture for emergencies. There's no rule saying anyone has to use a lens wide open—I've seen so many photos that could have been improved by stopping down—nothing wrong with stopping down to f/2 or f/4. What I noticed today in my 50mm f/1.7s (I didn't know I had two of them, but an extra one just showed up today) is that the iris pinwheels noticeably, which must affect bokeh, and not in a good way. I barely see this in the f/1.4, so I have to imagine the bokeh is cleaner.
This is what I have found in my four lenses, an SMC M 50mm f/1.4, two f/1.7s, and an f/2.0:
Wide open, the iris is a perfect circle of course, in all lenses.
The f/1.4 shows very minor pinwheeling (virtually unnoticeable) at f/2.0 and the next stop (the one in between f/2 and f2.8).
My f/1.7s are twins, showing major pinwheeling when stopped down to the stop before f/2.8 and at f/2.8.
The f/2.0 shows noticeable pinwheeling at f/2.8 and the stop before f/4, but it goes away at f/4.
So, apparently, this is something that is universal (and it applies to my 28mm f/2.8 as well): the iris is a perfect circle wide open, shows minor or major pinwheeling when stopped down once and then once again, and then the pinwheeling goes away completely when the lens is stopped down further.
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Forum: Monthly Photo Contests
01-02-2018, 07:55 AM
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Forum: Pentax Lens Articles
04-21-2016, 07:17 AM
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I can only speak for the K-50:
Using K-mount lenses with no "A" setting, you follow the information above, set the camera's mode button to "M", use the green button to stop down the lens and get a meter reading before shooting. It's usually within a stop or two of being correct, but I find adjustment is necessary almost every time to get a proper exposure. Regardless of the aperture setting, the iris remains open for focusing, and only closes down when the actual shot is taken or the green button is pushed.
Using M-42 mount lenses, you do NOT use the green button. Set the camera's mode dial to "AV" (or "TAV", but limit your ISO), choose the aperture you want on the lens, and the camera does the rest—well, you have to compose and focus, of course. With M-42 lenses, the aperture opens and closes as you turn the aperture dial. Focusing at f/8 and smaller apertures (higher numbers) can be a challenge, but exposure is usually right on the money—it's a bit like shooting with an automatic lens. Therefore, I actually prefer my M-42 lenses to my K-mount. Exposure is more accurate, and there's no futzing about with the green button.
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Forum: Pentax K-70 & KF
06-10-2016, 08:35 AM
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We're going to look back on the day when only a few of us brave-hearts (and independent thinkers) bought and used Pentax DSLRs against the marauding hordes of Canon and Nikon users. Cameras like this (at this price!) will put Pentax back in the running with the Big Two.
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Forum: Winners' Showcase
06-02-2016, 07:20 AM
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Has a bit of the Dutch Masters feel to it. I like it.
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Forum: Pentax Forums Giveaways
01-27-2016, 10:44 AM
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Need to modify an M-42 mount Adaptall lens for use on a Pentax K-mount camera without unscrewing delicate parts?
PROBLEM: My Adaptall lens, M-42 mount, would not stop down on my K-50—the small pin that closes the lens’s diaphragm does not get depressed by a digital camera.
SOLUTION: Using an X-Acto knife, I cut off the tip of an empty ballpoint pen refill (about 1/8 of an inch), slit it down one side to make a collar, and gently wedged that into the Adaptall ring—thus permanently lifting the little platform that the pin would push up.
Now, when I turn the aperture ring, the lens stops down, and the camera meters correctly (on the K-50, this works in AV mode). :)
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Forum: Pentax Price Watch
02-02-2016, 11:41 AM
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I sent my rebate info by certified mail and according to USPS it just sat in Promaster's PO box for more than two weeks from December 16th. I wrote to Promaster twice (at their "talk to a human" email address) and received no reply. When I received my rebate check (it took about a month in all), it was dated on 16 December. So, no acknowledgement from them at all, even in response to email, but the check finally did arrive. I got my new Pentax K-50 for $129! (after selling off the lens and the flash that it came with).
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Forum: Pentax Price Watch
11-27-2015, 10:35 AM
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I called Costco and was told that, if they could strike another deal with Pentax (Ricoh), a new ad would appear within 48 hours. If they did not get a new contract, the old ad would disappear. It disappeared. So, it doesn't look good for this amazing deal returning.
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Forum: Post Your Photos!
11-13-2015, 10:19 AM
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They both show beautiful, saturated colors, and no discernible noise (but I'm only viewing a small image)... nice artistic shots, but not really sharp.
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