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06-12-2019, 08:23 AM - 1 Like   #16
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Also try using CIF, it works pretty well when focusing fast, manual lenses.

06-12-2019, 08:33 AM - 1 Like   #17
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Maginified live view on F1.2 and 1.4 is the best option in my opinion. F2 can usually do OK with confirmation.

here is a cat shot at f1.4 on a MF rokinon 84 1.4 -- you can see the DOF is so shallow that even with a slight tilt of the head his nose and other eye are already out of focus

06-13-2019, 08:16 AM - 1 Like   #18
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I think what the original poster was referring to, is the suggestion that focusing screens nowadays have been optimized to work better with slower zoom lenses than old traditional ground glass type screens could ever do.

So many lenses these days have f5.6 apertures, and they would look pretty miserable if the finder had a traditional screen inside. Clever ways of molding optical patterns into the acrylic focusing screens make the image brighter to the eye - but at the expense of not looking brighter when using larger aperture lenses. So a 1.4 lens and 2.8 lens look equally bright to the eye - but that doesn't mean you can't accurately focus either, as previous posters have confirmed.

However (and here's the funny part), the 1.4 image is actually brighter through the finder as the light meter sees the same focusing screen you do, and the metering readouts reflect that. But the view through the eyepiece doesn't look brighter to the eye - it would have to do with the exit pupil diameter of the eyepiece, I gather.

The only real downside of all this wonderful tech is that a photographer shooting in truly low light (concerts, theatres, outdoors at night) doesn't benefit from the extra brightness of a fast lens when viewing through the finder. Back in the day, I remember that having a 1.4 lens on my camera made indoor photography a lot more enjoyable because I could actually see and compose better and faster - even if I was using flash and shooting at f8.0 or so.
Then again, really good cameras, like the K-1, have such good bright finders anyway, we don't usually worry about it.
06-13-2019, 09:09 AM - 2 Likes   #19
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There's some relevant information in this thread.
K-1 Automatically stops down my Pentax-a 50mm 1.4 in live view. - PentaxForums.com

My understanding is that Pentax AF is calibrated fro ƒ/2.8.
The issue with a wide opening lens is that it's anticipating ƒ2.8 DoF when locking focus, so the camera may choose a point somewhere within the 2.8 depth of field that is not exactly where you would have put it even though to the AF system it will be within acceptable focus.

But practically, shooting with mh DA* 55-1.4, the theoretical problem has never translate into an empirical issue.

You focus on the curly wire fence junction, you get the curly wire fence junction in focus in my experience, even at ƒ/1.4


If we listened to everyone who tells us what we can't do with our Pentax gear, we'd be missing out on an awful lot.

06-13-2019, 01:46 PM - 1 Like   #20
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QuoteOriginally posted by Ontarian50 Quote
I think what the original poster was referring to, is the suggestion that focusing screens nowadays have been optimized to work better with slower zoom lenses than old traditional ground glass type screens could ever do.

So many lenses these days have f5.6 apertures, and they would look pretty miserable if the finder had a traditional screen inside. Clever ways of molding optical patterns into the acrylic focusing screens make the image brighter to the eye - but at the expense of not looking brighter when using larger aperture lenses. So a 1.4 lens and 2.8 lens look equally bright to the eye - but that doesn't mean you can't accurately focus either, as previous posters have confirmed.

However (and here's the funny part), the 1.4 image is actually brighter through the finder as the light meter sees the same focusing screen you do, and the metering readouts reflect that. But the view through the eyepiece doesn't look brighter to the eye - it would have to do with the exit pupil diameter of the eyepiece, I gather.
As an aside, this is why it's fine to use a linear polarizing filter with Pentax digital bodies, especially if using manual focus. The worst you can do is make the AF hunt or become unresponsive if you cross polarize to death.
I think the only Pentax that doesn't ever play nice with a linear polarizer is the LX, where any degree of cross polarization will throw off the exposure.
06-13-2019, 05:12 PM - 3 Likes   #21
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Manual focus with a digital body just takes practice, like Wheatfield said , trust your eyes......I turned off the beep on my K3-II two weeks after I bought it...
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06-19-2019, 02:00 PM - 2 Likes   #22
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Just chiming in here, others have probably already told you this:
Make absolutely sure your diopter is adjusted correctly. Good autofocus has made us a little lazy.

Watch the focus indicator, not the red boxes telling you where you're focused.

Typically use the center focus point only.

If you need, investigate the magnifying eyepieces, they may be very helpful.

It's not as hard as you think. It certainly helps with a full-sized viewfinder. The old split-focus screens are useable in modern cameras. I had one in my K-10D. I think there isn't as much need now than there was then.
06-19-2019, 02:30 PM   #23
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QuoteOriginally posted by TER-OR Quote
Good autofocus has made us a little lazy.
I suggest AF made us lazy in the late 1990's - early 2000's. Since then as MP have increased and screen resolutions have increased we are able to pixel peep more than ever, and as a result have found the AF systems of our cameras to be lacking. This is why we have AF-FA menus now.

I too had a split screen in my K10D (still do actually). Don't find I need one with the K1.

06-20-2019, 05:30 AM   #24
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QuoteOriginally posted by pschlute Quote
I suggest AF made us lazy in the late 1990's - early 2000's. Since then as MP have increased and screen resolutions have increased we are able to pixel peep more than ever, and as a result have found the AF systems of our cameras to be lacking. This is why we have AF-FA menus now.

I too had a split screen in my K10D (still do actually). Don't find I need one with the K1.
Fair enough! Film prints at 4X6 were very forgiving!

I found the same thing in the K5 then K3II. I don't find myself wanting a split focus screen. In the field the autofocus works most of the time, once you learn how it works. The switch to manual is easy enough when required. Most often this is for stripy dragonflies perched on grass or reeds and the camera just can't figure out what I'm trying to photograph.

I would like a motorized focus version of the 100mm macro. The K3II's stronger screwdrive is fast, but using the motor focus lenses I have just makes me want that in the macro.
06-20-2019, 05:51 AM   #25
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QuoteOriginally posted by TER-OR Quote
Fair enough! Film prints at 4X6 were very forgiving!

I found the same thing in the K5 then K3II. I don't find myself wanting a split focus screen. In the field the autofocus works most of the time, once you learn how it works. The switch to manual is easy enough when required. Most often this is for stripy dragonflies perched on grass or reeds and the camera just can't figure out what I'm trying to photograph.

I would like a motorized focus version of the 100mm macro. The K3II's stronger screwdrive is fast, but using the motor focus lenses I have just makes me want that in the macro.
I'm not sure the speed of that lens is greatly hampered by the focus mechanism - I assumed it was due to the really long focus throw due to being a macro lens.
06-21-2019, 05:35 AM   #26
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QuoteOriginally posted by BugsDogsAndSunsets Quote
I'm not sure the speed of that lens is greatly hampered by the focus mechanism - I assumed it was due to the really long focus throw due to being a macro lens.
It's noticeably faster on my K3II than the K5. Some of that is focus engine, some of that is screw speed. The enhanced screw motors in the K3 line were supposed to be twice as fast, IIRC. Less hunting does make a difference, though, when you don't have to rack through the entire focus throw. I'm sure the engineers among us might be able to estimate whether such an upgrade is worthwhile.
06-21-2019, 09:23 AM   #27
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Possible topic migration warning!

I have a f2 50mm manual lens and I can focus it in the viewfinder no problem, Its great, but the question makes me think of my manual 500mm f8 mirror lens. I swear it seems like I see a sharp image and take the shot and its blurry. I think the lens is just soft, its not valueable so I can't expect it to be tack sharp.
An idea I had to test this is to make a short movie. I shoot the moon a lot with this and next time I should take a video, set it as sharp as I think it would be, tell the camera I think this is it, then move thru focus slowly and tell the camera I'm moving thru focus, play that back and my answer will be there!

Sorry if I derailed the thread. Seems like an interesting topic. No one ever told me that you can't focus an f2 lens in a viewfinder. Odd.
06-21-2019, 11:07 AM   #28
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Some of the older ovf struggled with manually focusing bright lenses. K10/20D and others had this problem. Pentax sold shim kits for owners to adjust their focusing screens. Slower lenses had more room for error.

Curious if the KP or K1 have focus sceen shim kits available?
Thanks,
barondla
07-03-2019, 03:39 PM - 1 Like   #29
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QuoteOriginally posted by barondla Quote
Some of the older ovf struggled with manually focusing bright lenses. K10/20D and others had this problem. Pentax sold shim kits for owners to adjust their focusing screens. Slower lenses had more room for error.

Curious if the KP or K1 have focus screen shim kits available?
Thanks,
barondla
I don't know if Pentax offers so (not to my knowledge) but as the focusing screen of the KP is 100% identical to the previous APS-S DSLR's from the K7 onwards,
i.e. K5, K3, K30/50/70, K-S1/2 you can use the shims from focusingscreen.com

I had several focusing screens from them in use.
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