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05-26-2016, 05:25 PM   #31
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QuoteOriginally posted by Wheatfield Quote
I find that I can fix fringing for the most part during raw conversion. As such I really don't care much if a lens fringes a bit. Pretty much any lens will show some issues if you push hard enough to find them.
When it comes down to the nub, old lenses don't have lens correction profiles embedded so the camera can't do the corrections. We have to fix it ourselves. That's an issue for a workflow-oriented photographer.

For me - I want to use old lenses - it's just another step in the process.

05-26-2016, 06:32 PM   #32
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QuoteOriginally posted by asharpe Quote
Does the K1 still have the exposure problem with old lenses that do not short out the mount contacts? This is the reason that I'm not using my (excellent) M42 lenses on my K3 so much anymore; I could not trust the meter to do the "right" thing. For a given aperture, I had to adjust the exposure compensation. For some of my photography, it was ok, since I used an external spotmeter. But I could not trust the K3's meter with M42 lenses, even using the green button instead of relying on Av mode. I'm using A lenses, and they are great, but I don't have the use of my amazing preset M42 1:1 macro-takumar, nor the M42 100 SMC macro.
I don't think any changes have been made in this respect, but for me a fixed exposure compensation did the trick.

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05-26-2016, 07:55 PM   #33
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QuoteOriginally posted by Adam Quote
I don't think any changes have been made in this respect, but for me a fixed exposure compensation did the trick.
Too bad. I (and others here) definitely have experienced the need to have a different exposure compensation for each aperture, and different compensation between lenses. I've heard that the other popular cameras that can use M42 lenses (Canon, Sony) don't have this "feature". Of course, Canon has trouble with old lenses hitting the mirror, and the Sony has an EVF, which I rather not have. I really don't understand why Pentax didn't "fix" this in the K1. The ability to use old lenses is really the most astonishing thing about Pentax, but I suppose those of us that use the old glass are still only a small minority.
05-26-2016, 08:56 PM   #34
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QuoteOriginally posted by asharpe Quote
Too bad. I (and others here) definitely have experienced the need to have a different exposure compensation for each aperture, and different compensation between lenses. I've heard that the other popular cameras that can use M42 lenses (Canon, Sony) don't have this "feature". Of course, Canon has trouble with old lenses hitting the mirror, and the Sony has an EVF, which I rather not have. I really don't understand why Pentax didn't "fix" this in the K1. The ability to use old lenses is really the most astonishing thing about Pentax, but I suppose those of us that use the old glass are still only a small minority.
Does the issue stem from the fact that matrix metering isn't selectable? You'd think there'd be a technical reason for that.


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05-26-2016, 09:42 PM   #35
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QuoteOriginally posted by Adam Quote
Does the issue stem from the fact that matrix metering isn't selectable? You'd think there'd be a technical reason for that.
I've heard (or read) that the issue is because of the calculations that Pentax does based on the fact that they know the aperture is wide open, and they know what it will be closed down to when the photo is taken. But with the old lenses, of course, the lens is not wide open when you take the reading, and the camera doesn't know what aperture is set (because of the crippled mount, or because the lens itself doesn't have a way to indicate the aperture, even on an M42 body). So, it calculates, but poorly. The green button is "supposed" to convince it to do the right thing, and it's better, certainly, but not as good as my A lenses.
05-27-2016, 03:38 AM - 1 Like   #36
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Is manual exposure that hard with manual lenses?

A test exposure using green mode then adjust to taste. This isn't film after all.

Anyway, this is how I use manual exposure lenses and even auto exposure.

If you are fussy with exposure, manual is always best.

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05-27-2016, 04:37 AM   #37
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I found green button metering to be way more accurate than on my K50 and haven't had any issues yet with it heavily under or overexposing.
05-27-2016, 06:13 AM   #38
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QuoteOriginally posted by Topsy Quote
I found green button metering to be way more accurate than on my K50 and haven't had any issues yet with it heavily under or overexposing.
I display histogram on the LCD, use Green Button to take a test shot, adjust until the histogram looks correct and change the aperture or shutter only when the light changes. Small adjustments made in post clean up the image, as necessary.

I suppose this works for me because I'm willing to take my time with manual lenses. I have modern lenses for situations where taking my time isn't possible. I do note that having the option to set up the K-1 with ISO on the third wheel opens a lot of possibilities.

It will be quite some time before I have fully learned the subtleties of the K-1 with manual lenses, but I bought the camera for that express purpose, and I have the time.

05-27-2016, 10:44 AM   #39
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QuoteOriginally posted by asharpe Quote
Does the K1 still have the exposure problem with old lenses that do not short out the mount contacts?
Are you talking about lenses with either anodized/painted/coated mount bases or bases that don't touch the contacts in the first place, like most M42 lenses?

I can't see how the K1 would fix those issues. The M42 stuff is specifically supposed to work that way. The lenses with coated bases get treated like M42 inappropriately, but they still work fine that way.

If you care about it a lot, there are a few ways to handle it:
-Sand off the coating (use appropriate precautions to avoid damaging the lens) - I did this with my porst 55/1.2 and one old 135 lens, and it works fine.
-aluminum tape on the lens mount base -- if the lens doesn't fit super tight on the camera, this works pretty well
-short the A pin inside the camera (I did this on my K5. It has some benefits and some detriments. It makes the camera think all lenses are A lenses, which is fine if you're shooting wide open or completely closed, but non-A lenses, the in-between apertures will be all kinds of screwed up because they changed the way the aperture blades move with the A series. I didn't bother with it on my K3 because it wasn't that useful in the long run)
- You can go total overkill, remove the mount plate, drill holes and add pins in the appropriate places to make the lens report itself with the correct aperture range.
05-27-2016, 10:57 AM   #40
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QuoteOriginally posted by narual Quote
Are you talking about lenses with either anodized/painted/coated mount bases or bases that don't touch the contacts in the first place, like most M42 lenses? I can't see how the K1 would fix those issues.
As I said above:
QuoteOriginally posted by asharpe Quote
I've heard (or read) that the issue is because of the calculations that Pentax does based on the fact that they know the aperture is wide open, and they know what it will be closed down to when the photo is taken. But with the old lenses, of course, the lens is not wide open when you take the reading, and the camera doesn't know what aperture is set (because of the crippled mount, or because the lens itself doesn't have a way to indicate the aperture, even on an M42 body). So, it calculates, but poorly. The green button is "supposed" to convince it to do the right thing, and it's better, certainly, but not as good as my A lenses.
The fact is, other cameras that accept M42 lenses (with adapters) don't have these exposure problems; they simply read through the lens and don't try to calculate anything. That's what the green button is supposed to do, but even that doesn't work as well as an A lens. So, yes, Pentax could indeed fix this, perhaps changing the way they calculate exposure if you set the Enable Aperture Ring setting.

Last edited by asharpe; 05-27-2016 at 11:02 AM.
05-27-2016, 05:13 PM   #41
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I've found green button metering is fine as long as I don't push the meter out of range when doing the measurement.
Your meter is only good to about EV -3, and is probably already not as accurate as it would be at positive EV numbers.
It's very easy to push a meter out of range when stop down metering is being used.
05-27-2016, 06:15 PM   #42
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QuoteOriginally posted by Wheatfield Quote
I've found green button metering is fine as long as I don't push the meter out of range when doing the measurement.
You lost me? Can you expand on this, and how it happens?
05-27-2016, 06:39 PM - 1 Like   #43
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QuoteOriginally posted by jatrax Quote
You lost me? Can you expand on this, and how it happens?
Your meter has an EV range of -3 to 20. -3 is equivalent to an exposure of f/1.4 for 4 seconds at ISO 400.
When we open aperture meter (any A series lens, be it auto or manual focus), we are metering wide open.
Using an M series or earlier, we are stopping the lens down to it's taking aperture and metering there.
If this stopping down cuts the amount of light going to the meter below EV-3, expect inaccurate exposures. I would be willing to bet that EV-3 is on the optimistic side and that metering accuracy will start to degrade a couple of stops above that.
05-27-2016, 08:41 PM   #44
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QuoteOriginally posted by Wheatfield Quote
If this stopping down cuts the amount of light going to the meter below EV-3, expect inaccurate exposures.
Got it, thank you. That actually makes a lot of sense, and might explain the OP's issue as well as the inconsistent metering I have seen with M42.
05-27-2016, 09:08 PM   #45
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QuoteOriginally posted by jatrax Quote
Got it, thank you. That actually makes a lot of sense, and might explain the OP's issue as well as the inconsistent metering I have seen with M42.
I wish it did (fully) explain it. It is certainly sounds like a contributing factor, but it does't explain why these lenses also meter incorrectly wide open and/or with plenty of light. As I have said before, it is likely the internal calculations that Pentax is doing that produce faulty readings; they assume that they have all the data about the lens, and with M42 they don't. So, instead of falling back to simply metering the light that comes through the lens, they alter that metering with a faulty algorithm.
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