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06-27-2014, 09:53 PM - 1 Like   #16
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QuoteOriginally posted by K David Quote
Does the K-30 have a diopter adjustment dial? If so, that may have been changed by the repair shop.
Because I'm using glasses, that's the first thing I check whenever something odd is going on with my focus....I read somewhere that one can do a global adjustment in AF fine settings of up to -10, but as all my AF lenses are spot on, I'd have to adjust all of them separately again. Perhaps I'll give that a try sometime

06-28-2014, 03:33 PM   #17
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QuoteOriginally posted by altopiet Quote
.I read somewhere that one can do a global adjustment in AF fine settings of up to -10, but as all my AF lenses are spot on, I'd have to adjust all of them separately again. Perhaps I'll give that a try sometime
There is a way to do that and that likely warrants it's own instructional post. I don't know how to do that yet (believe me -- some of m lenses would benefit from that.) I'll see what I can find out. Maybe you need to mail me your K-30 for a few weeks to see what I can do.
06-29-2014, 05:58 AM - 1 Like   #18
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I really look forward to this post. I'm a Pentax exec's worst nightmare: I shoot with a 4 year old Kx and (apart from my kit-lenses) I have four very nice manual lenses that cost me all of $30 in total! Recently started shooting with the Pentax f2 50 mm and I am rapidly falling in love with it. Smooth as butter with beautiful colours.

Keen to learn how to get the most from these brilliant (if slightly old-tech) lenses. All about the glass, eh?

As an aside- I would recommend to anyone to give manual a go. I found that, as it is harder, you think more about what you are doing and it shows!
06-30-2014, 01:36 AM   #19
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QuoteOriginally posted by K David Quote
There is a way to do that and that likely warrants it's own instructional post. I don't know how to do that yet (believe me -- some of m lenses would benefit from that.) I'll see what I can find out. Maybe you need to mail me your K-30 for a few weeks to see what I can do.
For what it's worth, I took the weekend and tried the global focus adjustment on the K-30, with my M50/1.4, without success.

I then started building up the shim of the focus screen with scotch tape, but in the end I removed the shim completely, and at last I can use CIF again, with a very slight FF. Focus confirmation also spot on, and everything actually working as it should when I get the clearest picture looking through the OVF

This indicates to me that the only way to get CIF and focus confirmation to match in focus image in OVF, is to play around with the shims and focus screen.

06-30-2014, 08:01 PM   #20
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QuoteOriginally posted by ivanvernon Quote
It might be a good idea to begin with a careful review of the various types/capabilities of manual lenses. I am thinking along these lines:

1. K-mount versus screw mount
2. Auto lenses (M-type) versus non-Auto lens
3. A-type lenses which in fact allow use of all modes, and where about the only difference in the lens and a fully modern auto-focus lens lies in the area of focussing.
I'd just like to second this. When I started looking in to legacy lenses (admittedly almost immediately from buying my K30) this was pretty confusing for me given the fairly large amount of lenses across different generations.

Might be worth including a brief mention of non-pentax manual focus lenses too, including some of the newer third party options.
07-16-2014, 07:59 AM - 1 Like   #21
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QuoteOriginally posted by ZeljkoS Quote
I'm interested in MF technique, especially for action shots. I like the IQ of my Pentax-A 50mm 1.7 but I can't get anything when the subject is moving

Try shooting cats with manual focus, it's a pain


Let the subject focus itself. By two methods.


Predictive focus:-


Set the focus to a preset place and as the subject moves into that zone of focus you will see them become sharp, release the shutter then.


Or


Follow focus:-


Follow them by panning and pull focus to keep up with them and snap the shutter at every opportunity when theyr sharp in the viewfinder.


You have to know the lens and which way the ring turns to infinity, then you get better at following focus as you pan the more you do it.


As a cat plays it will move in and out of the focus zone, stay sharp and youll get the shot.
07-17-2014, 09:29 AM   #22
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QuoteOriginally posted by Imageman Quote
Let the subject focus itself. By two methods.


Predictive focus:-


Set the focus to a preset place and as the subject moves into that zone of focus you will see them become sharp, release the shutter then.


Or


Follow focus:-


Follow them by panning and pull focus to keep up with them and snap the shutter at every opportunity when theyr sharp in the viewfinder.


You have to know the lens and which way the ring turns to infinity, then you get better at following focus as you pan the more you do it.


As a cat plays it will move in and out of the focus zone, stay sharp and youll get the shot.
Thanks for the tips, I'll try it out!

08-16-2014, 03:20 PM   #23
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QuoteOriginally posted by kadajawi Quote
How about the focusing scales on the lens, and the markings how the DoF will be depending on the aperture.
Hey, Kadajawi,

Here is a video I made a couple of years ago about hyperfocal distance and how to read lens scales:


I'll re-link this in the article's Q&A section.

---------- Post added 08-16-14 at 03:22 PM ----------

QuoteOriginally posted by kokezuniga Quote
Yeah, I have the same problem whem using a Pentax M 100mm f4 macro, the wireless flash doesn't work, any body know how to fix that?
Hey, Kokezuniga,

My guess is that it's your flash setting. I've only ever used manual flash settings, and I've never had an issue with a flash (being Pentax, Vivitar, or Westion -- the three brands I own) not firing. If it works other times, then the issues isn't with the flash.

I'll try to address this in the article's Q&A since a few people have asked about it.
08-19-2014, 08:49 AM   #24
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QuoteOriginally posted by K David Quote
Hey, Kadajawi,

Here is a video I made a couple of years ago about hyperfocal distance and how to read lens scales:

Hyperfocal Distance: Understanding and Using it - YouTube

I'll re-link this in the article's Q&A section.

---------- Post added 08-16-14 at 03:22 PM ----------



Hey, Kokezuniga,

My guess is that it's your flash setting. I've only ever used manual flash settings, and I've never had an issue with a flash (being Pentax, Vivitar, or Westion -- the three brands I own) not firing. If it works other times, then the issues isn't with the flash.

I'll try to address this in the article's Q&A since a few people have asked about it.
Thanks, that's a pretty good one. A few notes: From what I understand, the wider the lens, the bigger the hyperfocal range. Also, any 28mm lens should perform the same at the same aperture, though perhaps the optical quality might have an influence. But I think the difference between the scales has more to do with how optimistic the company is. Say on a 3 MP APS-C camera the hyperfocal range will be bigger than on a 24 MP APS-C camera, simply because you can see more detail, and you'll just notice much earlier that something is (ever so slightly) out of focus. Viewing distances, film stock, how picky the photographer is plays a role. The scale is more of a general advice than something you should 100% count on.


If I have the time I can focus on the closest point that needs to be in focus, mark it down or remember the position on the focus ring, then focus to the furthest point. Then I have to find the middle point between the two, and set the aperture to whatever is the widest open that covers both points (so that I won't waste sharpness on diffraction (?) from being beyond, say, f11).
08-19-2014, 10:29 AM   #25
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QuoteOriginally posted by kadajawi Quote
A few notes: From what I understand, the wider the lens, the bigger the hyperfocal range. Also, any 28mm lens should perform the same at the same aperture, though perhaps the optical quality might have an influence.
Yes, correct. In fact, some wide-angle lenses have distance scales that, at f22, exceed their marked focusing range.

As for 28mm all having the same hyperfocal range, I don't think I agree. I think that's a factor of focal length, yes, but also of lens design and probably some factors such as depth of focal plane (how much thicker the actual focal plane is than the film or sensor), focal plane curvature (lenses don't focus on a perfectly flat field), and focus height (distance from the rear element to the front of the focal plane.)

QuoteOriginally posted by kadajawi Quote
Say on a 3 MP APS-C camera the hyperfocal range will be bigger than on a 24 MP APS-C camera
Well, sort of yes. That's no so much a function of the lens, which has the same capabilities regardless of sensor, but of how capable the sensor is of seeing the imperfections in the lens' image. It would be worth considering that downsampling a larger image to a smaller one would likely result in the same in-focus effect as the smaller native image.

QuoteOriginally posted by kadajawi Quote
(so that I won't waste sharpness on diffraction (?) from being beyond, say, f11).
Depends on your camera. To my eyes, an sensor up to around 16 MP won't suffer diffraction softness until f13 or smaller. My K-3 starts to suffer it around f9 or f10, but this depends on the lens as f10 on a 300mm is a 30mm opening, but on a 50mm is a 5mm opening, so diffraction is almost never an issue with longer lenses, even stopped down to f29 or so.
08-24-2014, 10:51 PM   #26
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QuoteOriginally posted by K David Quote
Yes, correct. In fact, some wide-angle lenses have distance scales that, at f22, exceed their marked focusing range.

As for 28mm all having the same hyperfocal range, I don't think I agree. I think that's a factor of focal length, yes, but also of lens design and probably some factors such as depth of focal plane (how much thicker the actual focal plane is than the film or sensor), focal plane curvature (lenses don't focus on a perfectly flat field), and focus height (distance from the rear element to the front of the focal plane.)
Honestly I don't know. If you have the lenses though maybe you'd want to try it out, if you have way too much free time. i.e. wide open focus at the same point on a ruler for example that you'd use to calibrate for front and back focus, then stop down to f8 and take a photo. Put the photos next to each other. Using 2 lenses of the same focal length but maybe different price points and different hyperfocal scales.

QuoteQuote:
Well, sort of yes. That's no so much a function of the lens, which has the same capabilities regardless of sensor, but of how capable the sensor is of seeing the imperfections in the lens' image. It would be worth considering that downsampling a larger image to a smaller one would likely result in the same in-focus effect as the smaller native image.
So unless the manufacturer of lenses have agreed upon what exactly is considered still in focus it is entirely up to the manufacturer what scale to print on the lens.
08-25-2014, 10:53 AM   #27
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This may be a tough one but if you're concentrating on Pentax lenses then I would like to know how a lens design for a particular focal length changed, if it did at all. For example, can you trace the 50mm f/1.4 from the M42 mount Super Takumar to the current K mount FA? If someone were deciding between a M series 50mm f/1.7 and the F/FA 50mm f/1.7 then the question would be is the user giving up something in addition to AF between these designs?

Thanks!
08-25-2014, 04:21 PM   #28
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QuoteOriginally posted by 6BQ5 Quote
This may be a tough one but if you're concentrating on Pentax lenses then I would like to know how a lens design for a particular focal length changed, if it did at all. For example, can you trace the 50mm f/1.4 from the M42 mount Super Takumar to the current K mount FA? If someone were deciding between a M series 50mm f/1.7 and the F/FA 50mm f/1.7 then the question would be is the user giving up something in addition to AF between these designs?

Thanks!
M 50/1.4 begat A 50/1.4 begat F 50/1.4 begat FA 50/1.4 (all essentially similar optically with strong ties to the earlier K 50/1.4 and f/1.4 screw mount lenses)

M 50/1.7 begat A 50/1.7 begat F 50/1.7 begat FA 50/1.7 (all essentially similar optically with strong ties to the earlier K 55/1.8 and f/1.8 and f/2 screw mount lenses)

Short answer? No, there has not been a lot of change in regards to optical design. All trace their heritage to Asahi's take on the Zeiss Planar design. The big differences are in the coatings.

There is some discussion of whether the current DA 50/1.8 is optically similar to the 50/1.7 lenses above. I own the DA 50/1.8 and a few of the others and will be doing a comparison at some point if I can figure out a way to structure the match-up.


Steve
08-25-2014, 08:26 PM   #29
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QuoteOriginally posted by stevebrot Quote
M 50/1.4 begat A 50/1.4 begat F 50/1.4 begat FA 50/1.4 (all essentially similar optically with strong ties to the earlier K 50/1.4 and f/1.4 screw mount lenses)

M 50/1.7 begat A 50/1.7 begat F 50/1.7 begat FA 50/1.7 (all essentially similar optically with strong ties to the earlier K 55/1.8 and f/1.8 and f/2 screw mount lenses)

Short answer? No, there has not been a lot of change in regards to optical design. All trace their heritage to Asahi's take on the Zeiss Planar design. The big differences are in the coatings.

There is some discussion of whether the current DA 50/1.8 is optically similar to the 50/1.7 lenses above. I own the DA 50/1.8 and a few of the others and will be doing a comparison at some point if I can figure out a way to structure the match-up.


Steve
Up there! Up there! That's something I would really like to see. I have a number of older Tak's which I use both on my film bodies and my K-30. Their performance is extraordinary, especially considering their age. People today are running around after lenses costing several hundreds, if not several thousands of dollars! Yet, for $25 - $50 I can get a manual lens that is superb in my book. How did Asahi manage to "do it right the first time" like with these designs?
09-02-2014, 01:28 AM   #30
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Tips on how to manually focus. I use MF lenses exclusively and I still run into trouble when I'm shooting wide open and I end up focusing on a nose instead of eyes.
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