[ScooterMaxi Jim]

I might of overstated the f/1.4 situation a bit. Frankly, when shooting in low light requiring the fastest apertures I'm almost always going to use the K-01 with a screen magnifier - that is easily the consistently sharpest way to go. I've had a chance to test extensively lately due to some facial surgery in the family. Using just the screen (on the K-30) is probably second best option depending on the texture of the focal point. It is rare that I use the viewfinder when shooting wide open, but I do tend to be able to nail it in the range I typically use. Again, in recent years I just avoid shooting wider than f/2 - going to higher ISO rather than wide open.

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Last edited by ScooterMaxi Jim; 03-31-2014 at 10:21 PM.

[vonBaloney]

I might of overstated the f/1.4 situation a bit. Frankly, when shooting in low light requiring the fastest apertures I'm almost always going to use the K-01 with a screen magnifier - that is easily the consistently sharpest way to go. I've had a chance to test extensively lately due to some facial surgery in the family. Using just the screen (on the K-30) is probably second best option depending on the texture of the focal point. It is rare that that I use the viewfinder when shooting wide open, but I do tend to be able to nail it in the range I typically use. Again, in recent years I just avoid shooting wider than f/2 - going to higher ISO rather than wide open.

Yeah, but you're still FOCUSING wide-open, right? (Unless you're using m42 lenses maybe.) I also recently got a LCD viewfinder/magnifier for manual focus on the K-01, and it is marvelous (although you have to use zoom function because of stupid "feature" of it closing down the aperture partway in bright light otherwise, which throws off the focus). But with my s-screen on the K-5, I can nail anything in the viewfinder alone. (Most of my lenses are manual focus.) I do have a couple that are quite sharp at f/1.4, so I do shoot wide-open on those sometimes. And the DoF is razor-thin on the long telephotos so I need good calibration for that too.

[redrockcoulee]

At $300 for original Pentax extension tubes perhaps it is time to sell mine

When I was watching Hasselblad lenses a few years ago it seemed that they were gradually rising then a slight drop then a gradual rise and another small drop. I do not know what the trend in Pentax manual lenses are but I would guess that there is also a trend towards increased prices. Pentax stopped making them long ago and I doubt the demand has dropped and are they not useful for other formats such as micro 4/3s as well ?

[stevebrot]

Bottom line, I have no trouble nailing focus wide open on my several fine f/1.4 lenses

You're nailing MANUAL focus easily at f/1.4 with the stock screen?

My thoughts exactly vonBaloney. To paraphrase Inigo from "The Princess Bride", "I do think he knows what that word means...".


Steve

[monochrome]

I will say the K3 viewfinder is improved enough that accurately focusing an A50/1.4 is eminently doable.

[vonBaloney]

I will say the K3 viewfinder is improved enough that accurately focusing an A50/1.4 is eminently doable.

Really? What's the difference? The viewfinder is more magnified now -- it uses the same (sized) screen I thought as K-5, etc, right?

[monochrome]

Technically I can't tell you how or why it is better for me. What I know is I can use my K3 Right-Eye, without an external Correction Lens Adapter for the first time in a decade. I have been left-eye, assisted since 2004. I think a good deal of the change is just brightness - better coatings and a bit larger and more magnification. New internal diopter might also contribute. Whatever it is, I can see the subject snap into focus and I'm learning to trust what I see.

I have struggled with glaucoma and have run through a succession of film cameras and viewfinder aids trying to extend my time with the hobby. The K-01 and Q/Q7 have been an answer with magnified focus peaking. The LX with FB-1 / FC-1 Sports / Action Finder was another. Strangely, the ground glass matte, prism collar old film KX screen actually worked.

That's all I know.

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Last edited by monochrome; 03-31-2014 at 01:19 PM.

[stevebrot]

Really? What's the difference? The viewfinder is more magnified now -- it uses the same (sized) screen I thought as K-5, etc, right?

The issue in the past has always been the focus screen and the "brightening" (light scavenging) technology employed that resulted in viewfinder DOF being equivalent to no narrower than about f/4 regardless of lens mounted. This results in poor focus precision which yields a high proportion of missed focus shots. Precision has always been the issue,* not the perception of the ability to "nail" focus.

That being said, the extra magnification over the K10D/K20D generation of cameras is probably helpful as is adding a viewfinder magnifier (decreases DOF to allow for better precision). I have not done much work with the new generation camera, so I will shut my mouth now.


Steve

* There is no such thing as accurate, but imprecise. Precise, but inaccurate is quite doable, however

[vonBaloney]

I already have an unopened s-screen and magnifier sitting here for the K-3 I haven't even bought yet, so just wondering...

[monochrome]

I already have an unopened s-screen and magnifier sitting here for the K-3 I haven't even bought yet, so just wondering...

I can't imagine it will hurt you to install that. For me, since I'm not shooting a model's iris in studio lighting, getting within the Focus Zone is good enough. Shooting at f/5.6 from 10 feet with a 50mm lens in APSc I should have between 2.5 and 2.75 feet to work with. That gets me a head and shoulders of my wife with her face in sharp focus. Won't print 30x40 - but she won't let me do that anyway.

Flower and Bug Macro work with my 50 or 90 is on a tripod in Live View anyway, so . . . . .

My longest lens is a K200/2.5 and a converter. Great lens, but 'bird-on-a-branch' critical focus doesn't matter here, either (because 200 isn't enough to get a crop-able shot).

All the above is why I put the for me in italics.

[beebs]

I guess I'm still kinda puzzled about replacing the focusing screen...I mean, I loved my old split-image screen in the K-1000: you line it all up, you're in focus, it's all good, done. But do any of these replacement screens replicate that? I keep reading about having to use a dremel tool to get it to fit, and having to mess with shims, etc., and I'm not sure I want to go through all that.

I'm finding the stock screen is getting me as close as I can get, as the K-30 still "beeps" and flashes the stop-sign shape to let you know when it's in focus, but it would be cool to have a split-image in the very center to concentrate on again.

And to sorta get back to the topic, one of the lenses I've wanted to find is the M-series 20mm. There's currently one on eBay going for $313.10 and that is in BIDS, not buy-it-now. There were a coupla buy-it-nows that were ridiculous. And in the end I guess it just comes down to they only made so many, and there are people willing to pay silly amounts of money for things, which just skews things upward in general. I have vowed not to pay silly amounts of money for lenses.

Just read the reviews for that 17mm "fisheye" K-series lens...dangit...that looks cool, too......

[PPPPPP42]

I replaced the focusing screen for my K20D and the K5 looks identical so I would assume the K3 is the same as well.
It is actually super easy to do, you just take any little tool to snag the spring latch on the frame holding the focusing screen and it pops open and swings down. Its handy to have a correct tool to grab it by its tab (the only safe place to grab it) but you can use tweezers or other things, Ive gotten it with my hands even. The shim will be the little delicate flat metal rectangle that will fall out with the screen, its the same size as the screen and goes all the way around the border of it like a frame.
I can not explain how hard it is to get stuff off the screen including dust so USE A CLEAN WORKSPACE.
The screens are never the same thickness, there are maybe 5 but definitely less than 10 shims available for each body size and Pentax labels them A through H or something. Dunno how things are in Ricoh land now, but pre buyout you would call Pentax parts USA and if you were lucky you would get through to one totally overworked woman who you would tell to just send you the whole list of shims for your camera just to be safe, you never need them all but they don't cost too much and its stupid not to get them all shipped at once.

Then you can just honestly just 1/2 donkey+horse it and starting with the stock shim aim a camera with a fast 50 lens at a totally flat newspaper and focus on a specific line of print at about a 45 degree angle with even focus in front and in back and take a picture. If in the picture you have more in focus in front of (front focus) or behind (back focus) the line of print you selected than you either need a thicker or thinner shim I forget whether thinner or thicker corrects for back or front focus, you can look up which way it goes.
Its not very scientific to do it that way and people will tell you you need exact angles and fiddly focus charts but that's rather overrated so long as you aren't way off the angle and aim. Plus its easy to change later and you can check your answers with live view which bypasses the focus screen.
Do remember when choosing a screen that the split prism can interfere somewhat irregularly with spot meter mode though center weight and whatnot are fine.
I will eventually get an EE-S screen for my K5 I think as its pretty well useless visually manual focusing with the stock one and I want to use the spot meter mode more so no full featured Katzeye with prism and collar this time around which is what I bought for the K20D.

[ScooterMaxi Jim]

Yeah, but you're still FOCUSING wide-open, right? (Unless you're using m42 lenses maybe.) I also recently got a LCD viewfinder/magnifier for manual focus on the K-01, and it is marvelous (although you have to use zoom function because of stupid "feature" of it closing down the aperture partway in bright light otherwise, which throws off the focus). But with my s-screen on the K-5, I can nail anything in the viewfinder alone. (Most of my lenses are manual focus.) I do have a couple that are quite sharp at f/1.4, so I do shoot wide-open on those sometimes. And the DoF is razor-thin on the long telephotos so I need good calibration for that too.

Oddly enough, the whole "focus at wide open" is somewhat body dependent. For instance, the K-01 will focus wide open, the K-30 in VF mode is wide open, but the LV defaults to f/4 at the widest (presumably for sensor protection, but then they didn't implemented that for the K-01 - so a rather odd situation). In any event, the Samyang 85mm (and most fast telephotos) has measurable focus shift, so I do try to remember to stop down for critical focus.

As for screen switching - I've done my share of that (mostly on the LX). I wouldn't quite go as far as to say "super easy." It does take a steady hand, and often you end up do it more than once because it seems like dust almost always comes from somewhere.

[vonBaloney]

Oddly enough, the whole "focus at wide open" is somewhat body dependent. For instance, the K-01 will focus wide open, the K-30 in VF mode is wide open, but the LV defaults to f/4 at the widest (presumably for sensor protection, but then they didn't implemented that for the K-01 - so a rather odd situation). In any event, the Samyang 85mm (and most fast telephotos) has measurable focus shift, so I do try to remember to stop down for critical focus.

Both my K-01 and K-5 will stop down partway in live-view, but only in bright light (and with a fast enough lens) -- you can hear it opening and closing all the time depending on where you point it. And it is a real problem -- if you are shooting at f/2.8 and the lens is stopping down to f/4 or whatever for focus -- when it opens back up for the shot the focus will usually be off. However, if you hit the zoom manual focus assist function, it will stay wide-open while that is engaged. Which means you have to engage it every time even if you don't really need it, which is a pain.

[ScooterMaxi Jim]

Both my K-01 and K-5 will stop down partway in live-view, but only in bright light (and with a fast enough lens) -- you can hear it opening and closing all the time depending on where you point it. And it is a real problem -- if you are shooting at f/2.8 and the lens is stopping down to f/4 or whatever for focus -- when it opens back up for the shot the focus will usually be off. However, if you hit the zoom manual focus assist function, it will stay wide-open while that is engaged. Which means you have to engage it every time even if you don't really need it, which is a pain.

Nice catch on that. You are totally correct that the K-01 will stop down when the light gets bright enough (obviously for sensor preservation). Oddly, the K-30 stops down to f/4 no matter what. That's probably a better overall implementation - not only for consistency sake - but the unexpected stop-down noise is rather distracting (probably louder than the K-01 shutter). Engaging stop-down when planned doesn't bother me at all. I find it especially convenient on the K-30 with the RAW button on the side (a logical spot from a photographer's point of view).