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10-24-2013, 02:13 PM   #31
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QuoteOriginally posted by tripodquest Quote
It's for low light situations I have perfect+ vision. It takes a little getting used to, but it's possible to get perfect manual focus in really low light without seeking and without katzeye. I just managed it with my 50/1.7 wide open (without "seeking"), and to get a clear but a little underexposed result, I had to use iso800 + 0.6" at f/1.7, so I think that qualifies as low light. I just wanted to see if I can focus in that light.). Anything I will be shooting with the wide angle will be in a lot, lot more light than that... Because you just can't take the photos with f/2 or f/2.8 that you can with f/1.2 or f/1.7, and the viewfinder will be a lot darker. I'm getting the k3 so there is focus peaking, if it doesn't work in really low light I'll use my eyes and practice, practice, practice. I believe you can learn every lens to its full potential if you put in the time.

The "new" viewfinders have a 0.95x magnification. But now that I think about it, things at any distance will seem smaller through a wide angle lens. I wonder if that will make the focusing more difficult? I don't know. I'll just have to try.
Good luck. I also have "perfect+" vision and can tell you from experience that critical focus with any degree of precision is essentially not possible with the stock Pentax screen. The reason is that the DOF is never less than what you would see for f/4. That is a lot of wiggle room. Now if you are not picky that may be fine, but I do know that I did not get reasonable focus control with my faster lenses (including the f/2.8 Zenitar) until got the split-image/microprism Katz Eye. There is a reason why focus aids were standard equipment on pre-AF film cameras.

Things might be better with focus peaking, though I can't imagine doing critical focus at wide apertures and having the camera-to-subject distance being maintained while holding the camera out away from the face. Braced with the strap against the neck, perhaps?

I bolded part of your comment above and can relate that indeed everything is indeed smaller. If comes along as part of the package with the increased FOV and does indeed make focusing harder, much harder.

In any case, good luck.


Steve

10-24-2013, 02:20 PM   #32
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QuoteOriginally posted by stevebrot Quote
I can't imagine doing critical focus at wide apertures and having the camera-to-subject distance being maintained while holding the camera out away from the face.
Works fine for me with the A50/1.2 on a K-01.
Just have to go easy on the coffee!
10-24-2013, 03:29 PM   #33
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QuoteOriginally posted by stevebrot Quote
Good luck. I also have "perfect+" vision and can tell you from experience that critical focus with any degree of precision is essentially not possible with the stock Pentax screen. The reason is that the DOF is never less than what you would see for f/4. That is a lot of wiggle room. Now if you are not picky that may be fine, but I do know that I did not get reasonable focus control with my faster lenses (including the f/2.8 Zenitar) until got the split-image/microprism Katz Eye. There is a reason why focus aids were standard equipment on pre-AF film cameras.

Things might be better with focus peaking, though I can't imagine doing critical focus at wide apertures and having the camera-to-subject distance being maintained while holding the camera out away from the face. Braced with the strap against the neck, perhaps?

I bolded part of your comment above and can relate that indeed everything is indeed smaller. If comes along as part of the package with the increased FOV and does indeed make focusing harder, much harder.

In any case, good luck.


Steve
Thank you. I have considered katzeye, the pentax stock screen is really dark, there's no denying that, and the katzeye isn't that expensive (but I would rather pay $50 (or $20...) , and [b]if anyone can suggest me a Chinese version of KatzEye[b] that works just as well I would rather buy that. I really only want it to brighten the view, I don't need anything else though the focus help like in this one Dual 45° Split Image Focus Focusing Screen for Pentax K7 K 7 K5 K 5 DSLR Camera | eBay would be nice too, and that one only costs $20 but I don't know if it's any good. I've spent $1300 on camera related stuff this WEEK... So you might understand wanting to pay less. The test I did was just for fun... Mind you, I needed a minute for my eyes to get used to the light, I had the LCD completely off and I had to stare through the screen for a while before taking the picture. It was REALLY low light, but the picture WAS in focus where I was focusing. But in anything but moderately low light and below f/2, you're right, you can't use it for critical work. 1.2 works fine of course... Even handheld, like lytrytyr said. I think 50/1.2 is a MUST for any photographer... But if you only have slow lenses, you might have a different perspective.
QuoteOriginally posted by lytrytyr:
Hah. I only drink about a liter a day... That counts as going easy, right?
10-24-2013, 06:08 PM - 1 Like   #34
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QuoteOriginally posted by tripodquest Quote
the pentax stock screen is really dark, there's no denying that,
The Katz Eye is no brighter even with the Optibrite treatment. The problem with the stock screen in not brightness, it is apparent DOF. You can demonstrate with this with your 50/1.7 using the optical DOF preview. Set the aperture ring at f/3.5 and actuate the DOF preview. Do you see a difference? Unless things have changed with the more recent bodies, you probably won't. In fact, you may not notice any appreciable dimming of the viewfinder. Now consider the difference in DOF between f/1.7 and f/3.5 and realize that the image you are using to focus with at f/1.7 has an effective DOF of f/3.5 while the image on the sensor has DOF for f/1.7.

Katz Eye makes a good product, but I would also consider focusingscreen.com or cut down your own from available Nikon or Canon options. I would cut my own before using any of the eBay vendors.

As for perspective on fast lenses, my signature is not real complete. I don't own a f/1.2 lens. I consider them a bit of a novelty item and poor value for general shooting (heavy, bulky, expensive, etc.). They are nice for abstract floral work and soft-touch portraits though. I do own a Rokkor (Minolta) 58/1.4 and Auto-Rikenon (Ricoh/Tomioka) 55/1.4. Both are nice lenses with the Rokkor being the better of the two. I used to own a Super Takumar 50/1.4, but found the performance disappointing for the scant 1/2 stop jump from my ST 55/1.8.

That last point is the important one. Almost all f/1.7 and f/1.8 Pentax (and Asahi) normal lenses are optically better at all shared apertures than their f/1.4 brethren. The f/1.2 and f/1.4 lenses generally are pretty soft and lacking in contrast at maximum aperture. My f/1.7, f/1.8, and f/2 lenses are ALL better than my two f/1.4.


Steve

10-24-2013, 06:18 PM   #35
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QuoteOriginally posted by stevebrot Quote
The Katz Eye is no brighter even with the Optibrite treatment. The problem with the stock screen in not brightness, it is apparent DOF. You can demonstrate with this with your 50/1.7 using the optical DOF preview. Set the aperture ring at f/3.5 and actuate the DOF preview. Do you see a difference? Unless things have changed with the more recent bodies, you probably won't. In fact, you may not notice any appreciable dimming of the viewfinder. Now consider the difference in DOF between f/1.7 and f/3.5 and realize that the image you are using to focus with at f/1.7 has an effective DOF of f/3.5 while the image on the sensor has DOF for f/1.7.

Katz Eye makes a good product, but I would also consider focusingscreen.com or cut down your own from available Nikon or Canon options. I would cut my own before using any of the eBay vendors.

As for perspective on fast lenses, my signature is not real complete. I don't own a f/1.2 lens. I consider them a bit of a novelty item and poor value for general shooting (heavy, bulky, expensive, etc.). They are nice for abstract floral work and soft-touch portraits though. I do own a Rokkor (Minolta) 58/1.4 and Auto-Rikenon (Ricoh/Tomioka) 55/1.4. Both are nice lenses with the Rokkor being the better of the two. I used to own a Super Takumar 50/1.4, but found the performance disappointing for the scant 1/2 stop jump from my ST 55/1.8.

That last point is the important one. Almost all f/1.7 and f/1.8 Pentax (and Asahi) normal lenses are optically better at all shared apertures than their f/1.4 brethren. The f/1.2 and f/1.4 lenses generally are pretty soft and lacking in contrast at maximum aperture. My f/1.7, f/1.8, and f/2 lenses are ALL better than my two f/1.4.


Steve
Oh... i read about the optiBrite and that was pretty much the only reason I wanted to buy it. Thank you for telling me about that! I will try what you said with my 1.7 now. What the... Okay, you really surprised me there. I had never even noticed that before. That really got me by surprise. Is the screen as bad in k-3? Pentax should really invest some thought in their viewfinder/screen design. Is there anything that will make the VF brighter for those really low light situations? Or do I just have to rely on my eyes?
10-24-2013, 07:17 PM   #36
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QuoteOriginally posted by tripodquest Quote
Oh... i read about the optiBrite and that was pretty much the only reason I wanted to buy it. Thank you for telling me about that! I will try what you said with my 1.7 now. What the... Okay, you really surprised me there. I had never even noticed that before. That really got me by surprise. Is the screen as bad in k-3? Pentax should really invest some thought in their viewfinder/screen design. Is there anything that will make the VF brighter for those really low light situations? Or do I just have to rely on my eyes?
I haven't mucked around with the screen personally, but some screens are better optimized to wider apertures than others.

The canon ee-s (?) I believe was one of the screens that was highly touted for wide aperture lenses. Unfortunately it needs to be cut down for use on Pentax.
10-24-2013, 07:20 PM   #37
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QuoteOriginally posted by ElJamoquio Quote
I haven't mucked around with the screen personally, but some screens are better optimized to wider apertures than others.

The canon ee-s (?) I believe was one of the screens that was highly touted for wide aperture lenses. Unfortunately it needs to be cut down for use on Pentax.
cut down... like, cut the glass? sounds a little too involved for me.

10-25-2013, 01:17 AM   #38
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QuoteOriginally posted by tripodquest Quote
cut down... like, cut the glass? sounds a little too involved for me.
Or you can buy it from focusingscreen.com accurately pre-cut with all the required shims and an installation kit. The only way to accurately focus manual lenses, fast or slow.
10-25-2013, 04:47 AM   #39
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QuoteOriginally posted by kh1234567890 Quote
The only way to accurately focus manual lenses, fast or slow.
That has changed now, with focus peaking.

Even so, with focus shift when stopping down fast lenses,
focus bracketing is still advisable.
10-25-2013, 05:04 AM   #40
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QuoteOriginally posted by lytrytyr Quote
That has changed now, with focus peaking.
Have you actually tried it with a hand-held manual telephoto ?
10-25-2013, 06:52 AM   #41
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QuoteOriginally posted by kh1234567890 Quote
Have you actually tried it with a hand-held manual telephoto ?
SOP with adapted K lenses on the Q. See:

https://www.pentaxforums.com/forums/pentax-q/240364-anyone-use-closeup-lens-0...ml#post2551576

Focus was on the "hairs."
10-25-2013, 07:08 AM   #42
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QuoteOriginally posted by lytrytyr Quote
SOP with adapted K lenses on the Q. See:

https://www.pentaxforums.com/forums/pentax-q/240364-anyone-use-closeup-lens-0...ml#post2551576

Focus was on the "hairs."
Now try it with a heavy old telephoto on a DSLR, hand-held, bright sun shining on your LCD, a street or sports shot where a second's delay would make all the difference ...
10-25-2013, 09:29 AM   #43
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QuoteOriginally posted by kh1234567890 Quote
Or you can buy it from focusingscreen.com accurately pre-cut with all the required shims and an installation kit. The only way to accurately focus manual lenses, fast or slow.
Thank you. Can you say if that will help with older lenses that are not as contrasty, or somewhat softer? I have a telephoto zoom (from Russia) that is somewhat slow and the focusing needs really fine work, moving the focus ring a millimeter makes a huge difference so it's like a hair trigger zoom... I use it in daylight so the brightness is not the problem but I need to use live view and digital zoom if I want to focus accurately (for example, focus on the correct branch or leaf of a tree with many levels of branches). Seeing whether what you want to focus on is in perfect focus, hyperfocal focus or just soft focus is pretty much impossible. I can get pictures where what I want in focus is in focus but... I don't have the control I would like. Finetuning the focus is impossible with the LV, just getting things in focus is enough of a challenge. It seems that the viewfinder accentuates the lack of contrast so that the pictures look more contrasty than what I see through the viewfinder. Do you think a focusing screen would help with this?
10-25-2013, 12:43 PM   #44
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sigma 14mm 2.8

Is the sigma 14mm non fisheye 2.8 lens made for a full frame camera?
10-25-2013, 12:48 PM   #45
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Yes, it is.
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