View finder size comparison

LesDMess · 03-10-2016, 08:03 AM

Originally posted by ColiNiloK

And lastly a simple viewfinder magnifier should make the K-1's viewfinder much bigger.

Unfortunately that comes at a significant loss of light.

As photographers, we're used to working with what we have. As the song goes, "If you can't be with the one you love, love the one you're with."

Last edited by LesDMess; 03-10-2016 at 08:10 AM.

Pentaxis · 03-10-2016, 08:42 AM

Originally posted by stevebrot

To put everything in actual (degrees of arc) rather than relative units...

Diagonal FOV 50mm at infinity corrected by magnification and format

K-3 (APS-C) = 32.2° * 0.95 = 30.6°
K-1 (24x36) = 46.8° * 0.7 = 32.8°
5DM3 (24x36) = 46.8° * 0.71 = 33.2°
A900 (24x36) = 46.8° * 0.74 = 34.6°

Difference (A900 - K-3) = 4.0° (+12%)
Difference (K-1 - K-3) = 2.2° (+ 7%)
Difference (A900 - K-1) = 1.8° (+5%)
Difference (A900 - 5DM3) = 1.4° (+4%)
Difference (5DM3 - K-1) = 0.4° (+1%)

Note: I may have misunderstood how to do these calculations. I will update if I discover otherwise.

Steve

Yes. This is disappointing.

As I said in my original posting, my expectations are conditioned by use of the ME Super: this, as you agreed in your earlier earlier posting, has a beautiful finder. It calculates as being 25% bigger than the K-1. Gulp!

I have never used a digital SLR at all and am trying to understand why there is the apparent substantial reduction in finder field of view. One reason might be that the eye relief is greater on the K-1. The other might be, as I suggested ealier, that there is a need to display more symbology outside the imege field.

**monochrome** · 03-10-2016, 08:55 AM

Originally posted by Pentaxis

Yes. This is disappointing.

As I said in my original posting, my expectations are conditioned by use of the ME Super: this, as you agreed in your earlier earlier posting, has a beautiful finder. It calculates as being 25% bigger than the K-1. Gulp!

I have never used a digital SLR at all and am trying to understand why there is the apparent substantial reduction in finder field of view. One reason might be that the eye relief is greater on the K-1. The other might be, as I suggested ealier, that there is a need to display more symbology outside the imege field.

Given the uniquity of AF lenses, viewfinder acuity today is not as high a priority as it was in the 70's.

stevebrot · 03-10-2016, 10:58 AM

Originally posted by monochrome

Given the uniquity of AF lenses, viewfinder acuity today is not as high a priority as it was in the 70's.

...and there is the dirty little secret that the PDAF system steals a significant amount of light from the optical viewfinder path*. The resulting side-effects severely degrade the ability of the designer to offer decent viewfinder size, brightness, and focus sensitivity.

Steve

* It is not immediately obvious, but the main mirror is half-silvered.

**RobA_Oz** · 03-10-2016, 12:59 PM

Originally posted by LesDMess

Unfortunately that comes at a significant loss of light.

There'll be some (small) transmission loss in a magnifier, but magnification lowers the brightness in proportion to the square of the magnification factor. Given that the viewfinder image in the K-1 will be nearly twice as bright as that in the K-3, a 1.3x magnifier will lower that by a factor of 1.69, so the resultant eyepiece image will be bigger and a little brighter than that of the naked K-3 eyepiece. It isn't all bad.

alan_smithee_photos · 03-10-2016, 01:28 PM

Bummer the K-1's finder isn't going to be bigger. I shoot hybrid (film + digital) regularly and the difference in switching between my K-5 IIs and LX or K1000 is substantial: the big, beautiful viewfinders on the film cameras just blow the poor little K-5 out of the water. Was really hoping the K-1 would be more competitive with the old film finders.

stevebrot · 03-10-2016, 02:56 PM

Originally posted by RobA_Oz

Given that the viewfinder image in the K-1 will be nearly twice as bright as that in the K-3

That is the second time you have said that and I am puzzled. For a given relative aperture (f number) the luminance flux to the focus screen is the same regardless of the crop.* Edit: I had forgotten about the reduction in magnification effectively concentrating the light to that of the smaller apparent area. Many thanks to @Cannikin for reminding me of how things work.

Steve

* There are assumptions regarding attenuation due to incident angle at the margins. Some fall-off in the corners is unavoidable.

Last edited by stevebrot; 03-10-2016 at 06:43 PM.

stevebrot · 03-10-2016, 02:59 PM

Originally posted by alan_smithee_photos

Was really hoping the K-1 would be more competitive with the old film finders.

Pentax (along with most other makers) has not fielded a decent optical viewfinder in any of their 35mm AF bodies.

Welcome to the unintended future.

Steve

Cannikin · 03-10-2016, 05:47 PM

Originally posted by stevebrot

That is the second time you have said that and I am puzzled. For a given relative aperture (f number) the luminance flux to the focus screen is the same regardless of the crop.

Except the image in the viewfinder is not the focusing screen itself. You are looking at a projection from the pentaprism in which the light passing through the FF focusing screen, with over twice the area of APS-C, is concentrated into a visual area only slightly larger than a K-3's pentaprism projection.

It is the same principle as to why a focal reducer ("speed booster") creates a brighter image, and a teleconverter creates a darker image.

stevebrot · 03-10-2016, 06:39 PM - **1 Like**

Originally posted by Cannikin

You are looking at a projection from the pentaprism in which the light passing through the FF focusing screen

OK, let me walk myself through this...The image is not an aerial image. It is projected on the surface of the screen in the same manner as the ground glass on my view camera and the focus screen is the same size as the sensor. It is that image that is used by the camera meter system. What I had forgotten is that reduction in magnification is accomplished by the optical system of the prism and viewfinder ocular. So, you and @RobA_Oz are correct and I am mistaken. There would be amplification of brightness on the order of what RobA_Oz suggested. I will edit my comment appropriately.

How Ricoh/Pentax uses that extra brightness might prove interesting.

Steve

JBox · 03-10-2016, 08:03 PM

Originally posted by alan_smithee_photos

Bummer the K-1's finder isn't going to be bigger. I shoot hybrid (film + digital) regularly and the difference in switching between my K-5 IIs and LX or K1000 is substantial: the big, beautiful viewfinders on the film cameras just blow the poor little K-5 out of the water. Was really hoping the K-1 would be more competitive with the old film finders.

This is exactly what I do as well (film + digital). The difference between the LX FA-1 and K-5 is pretty mind blowing. I am hoping the difference between the LX FA-1 and the K-1 is a little less shocking. Some other random observations (not spec based): To me the Super A is noticeably smaller than the LX but is still very usable. I think the Super A must be much brighter than the K-5 for example. I can't see any difference between the ME Super and the LX FA-1 even though the ME Super is somewhat smaller. I am hoping for a difference between the LX and the K-1 that is similar to the difference between LX and the Super A. Based on the calculations here and my own, it should be close-ish.

Originally posted by stevebrot

Added: A bit of trivia...a 1x viewfinder may be used with both eyes open since the magnification is the same as unaided eye. With rangefinder cameras having such (rare), this is a distinct advantage in that it allows the photographer use of their peripheral vision.

I have done this with the LX FA-1 and a 50mm lens and it worked for me.

LesDMess · 03-10-2016, 08:40 PM

Originally posted by RobA_Oz

There'll be some (small) transmission loss in a magnifier, but magnification lowers the brightness in proportion to the square of the magnification factor. Given that the viewfinder image in the K-1 will be nearly twice as bright as that in the K-3, a 1.3x magnifier will lower that by a factor of 1.69, so the resultant eyepiece image will be bigger and a little brighter than that of the naked K-3 eyepiece. It isn't all bad.

I have a variety of magnifiers that are helpful but all will darken the viewfinder and of course not useful unless tripod mounted like live view.

Good or bad it doesn't matter now that the K-1 features are solidified. Hopefully it will be successful enough so we can possibly get these features added to the next one . . .

**RobA_Oz** · 03-10-2016, 09:33 PM

Originally posted by LesDMess

I have a variety of magnifiers that are helpful but all will darken the viewfinder and of course not useful unless tripod mounted like live view.

Good or bad it doesn't matter now that the K-1 features are solidified. Hopefully it will be successful enough so we can possibly get these features added to the next one . . .

Yes they do, as I said, but if the resultant eyepiece image is both bigger and brighter (even with a magnifier of less than 1.5x), then we can all relax about this, because we're doing better than we have now (which isn't all that bad, really).

With my slowly declining eyesight, I need all the luminous flux I can get, especially with an OVF (and, yes, I do have an EVF camera, as well).

LesDMess · 03-10-2016, 09:54 PM

Originally posted by RobA_Oz

Yes they do, as I said, but if the resultant eyepiece image is both bigger and brighter (even with a magnifier of less than 1.5x), then we can all relax about this, because we're doing better than we have now (which isn't all that bad, really).

With my slowly declining eyesight, I need all the luminous flux I can get, especially with an OVF (and, yes, I do have an EVF camera, as well).

No doubt a reference is needed here but unfortunately my point of reference has no equal in the viewfinder department. I understand that the priority is reliance on autofocus so it is what it is.

**gaweidert** · 03-12-2016, 10:40 AM - **1 Like**

I have to admit that I am put off by the .7x magnification of the viewfinder. When I got to this fact when reading the specs it really deflated me. I was hoping for a viewfinder more akin to my Ricoh XRM or Pentax Spotmatic II. I want a split image center surrounded by a micro prism circle for my old eyes, I prefer manual focus to auto focus. Most of the shots with my Tamron 70-210 F2.8 and Pentax 150-450 are made using manual focus.

After 45 years of using manual focus lenses I am pretty good at it. But I need a better viewfinder to help me accomplish this. Focus confirmation on my K5 is spotty at best. My k5-IIs is a bit better and the K3 even better, but I want the lens to focus where I want to it and not some computer algorithm. I'm really bummed out about this. Pentax let me down a bit with this camera. It has been a long wait and I had hoped for a true full frame camera in all respects. And yes I was prepared to pay for it. I will probably still get it, but not until after actually handling one.

I know I am sounding old and set in my ways, but not all the old ways are the wrong way.

On a happier note, the crocuses are in full bloom with it the promise of spring and for me personally, retirement.

03-10-2016, 06:39 PM - 1 Like	#25
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Cannikin You are looking at a projection from the pentaprism in which the light passing through the FF focusing screen OK, let me walk myself through this...The image is not an aerial image. It is projected on the surface of the screen in the same manner as the ground glass on my view camera and the focus screen is the same size as the sensor. It is that image that is used by the camera meter system. What I had forgotten is that reduction in magnification is accomplished by the optical system of the prism and viewfinder ocular. So, you and @RobA_Oz are correct and I am mistaken. There would be amplification of brightness on the order of what RobA_Oz suggested. I will edit my comment appropriately. How Ricoh/Pentax uses that extra brightness might prove interesting. Steve Last edited by stevebrot; 03-10-2016 at 07:35 PM.

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03-10-2016, 08:03 AM	#16
LesDMess Pentaxian Join Date: May 2011 Location: Santa Cruz, CA Photos: Albums Posts: 3,235	Originally posted by ColiNiloK And lastly a simple viewfinder magnifier should make the K-1's viewfinder much bigger. Unfortunately that comes at a significant loss of light. As photographers, we're used to working with what we have. As the song goes, "If you can't be with the one you love, love the one you're with." Last edited by LesDMess; 03-10-2016 at 08:10 AM.

03-10-2016, 08:42 AM	#17
Pentaxis Senior Member Join Date: Jul 2012 Posts: 195	Originally posted by stevebrot To put everything in actual (degrees of arc) rather than relative units... Diagonal FOV 50mm at infinity corrected by magnification and format K-3 (APS-C) = 32.2° * 0.95 = 30.6° K-1 (24x36) = 46.8° * 0.7 = 32.8° 5DM3 (24x36) = 46.8° * 0.71 = 33.2° A900 (24x36) = 46.8° * 0.74 = 34.6° Difference (A900 - K-3) = 4.0° (+12%) Difference (K-1 - K-3) = 2.2° (+ 7%) Difference (A900 - K-1) = 1.8° (+5%) Difference (A900 - 5DM3) = 1.4° (+4%) Difference (5DM3 - K-1) = 0.4° (+1%) Note: I may have misunderstood how to do these calculations. I will update if I discover otherwise. Steve Yes. This is disappointing. As I said in my original posting, my expectations are conditioned by use of the ME Super: this, as you agreed in your earlier earlier posting, has a beautiful finder. It calculates as being 25% bigger than the K-1. Gulp! I have never used a digital SLR at all and am trying to understand why there is the apparent substantial reduction in finder field of view. One reason might be that the eye relief is greater on the K-1. The other might be, as I suggested ealier, that there is a need to display more symbology outside the imege field.

03-10-2016, 08:55 AM	#18
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	Originally posted by Pentaxis Yes. This is disappointing. As I said in my original posting, my expectations are conditioned by use of the ME Super: this, as you agreed in your earlier earlier posting, has a beautiful finder. It calculates as being 25% bigger than the K-1. Gulp! I have never used a digital SLR at all and am trying to understand why there is the apparent substantial reduction in finder field of view. One reason might be that the eye relief is greater on the K-1. The other might be, as I suggested ealier, that there is a need to display more symbology outside the imege field. Given the uniquity of AF lenses, viewfinder acuity today is not as high a priority as it was in the 70's.

03-10-2016, 10:58 AM	#19
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by monochrome Given the uniquity of AF lenses, viewfinder acuity today is not as high a priority as it was in the 70's. ...and there is the dirty little secret that the PDAF system steals a significant amount of light from the optical viewfinder path. The resulting side-effects severely degrade the ability of the designer to offer decent viewfinder size, brightness, and focus sensitivity. Steve It is not immediately obvious, but the main mirror is half-silvered.

03-10-2016, 12:59 PM	#20
RobA_Oz Site Supporter Join Date: Nov 2008 Location: Tasmania, Australia Photos: Gallery Posts: 8,200	Originally posted by LesDMess Unfortunately that comes at a significant loss of light. There'll be some (small) transmission loss in a magnifier, but magnification lowers the brightness in proportion to the square of the magnification factor. Given that the viewfinder image in the K-1 will be nearly twice as bright as that in the K-3, a 1.3x magnifier will lower that by a factor of 1.69, so the resultant eyepiece image will be bigger and a little brighter than that of the naked K-3 eyepiece. It isn't all bad.

03-10-2016, 01:28 PM	#21
alan_smithee_photos Veteran Member Join Date: May 2009 Location: Seattle, WA Posts: 844	Bummer the K-1's finder isn't going to be bigger. I shoot hybrid (film + digital) regularly and the difference in switching between my K-5 IIs and LX or K1000 is substantial: the big, beautiful viewfinders on the film cameras just blow the poor little K-5 out of the water. Was really hoping the K-1 would be more competitive with the old film finders.

03-10-2016, 02:56 PM	#22
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by RobA_Oz Given that the viewfinder image in the K-1 will be nearly twice as bright as that in the K-3 That is the second time you have said that and I am puzzled. For a given relative aperture (f number) the luminance flux to the focus screen is the same regardless of the crop.* Edit: I had forgotten about the reduction in magnification effectively concentrating the light to that of the smaller apparent area. Many thanks to @Cannikin for reminding me of how things work. Steve * There are assumptions regarding attenuation due to incident angle at the margins. Some fall-off in the corners is unavoidable. Last edited by stevebrot; 03-10-2016 at 06:43 PM.

03-10-2016, 02:59 PM	#23
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by alan_smithee_photos Was really hoping the K-1 would be more competitive with the old film finders. Pentax (along with most other makers) has not fielded a decent optical viewfinder in any of their 35mm AF bodies. Welcome to the unintended future. Steve

03-10-2016, 05:47 PM	#24
Cannikin Veteran Member Join Date: Mar 2010 Location: SW Washington Posts: 833	Originally posted by stevebrot That is the second time you have said that and I am puzzled. For a given relative aperture (f number) the luminance flux to the focus screen is the same regardless of the crop. Except the image in the viewfinder is not the focusing screen itself. You are looking at a projection from the pentaprism in which the light passing through the FF focusing screen, with over twice the area of APS-C, is concentrated into a visual area only slightly larger than a K-3's pentaprism projection. It is the same principle as to why a focal reducer ("speed booster") creates a brighter image, and a teleconverter creates a darker image.

03-10-2016, 08:03 PM	#26
JBox Senior Member Join Date: Aug 2011 Location: Michigan Posts: 109	Originally posted by alan_smithee_photos Bummer the K-1's finder isn't going to be bigger. I shoot hybrid (film + digital) regularly and the difference in switching between my K-5 IIs and LX or K1000 is substantial: the big, beautiful viewfinders on the film cameras just blow the poor little K-5 out of the water. Was really hoping the K-1 would be more competitive with the old film finders. This is exactly what I do as well (film + digital). The difference between the LX FA-1 and K-5 is pretty mind blowing. I am hoping the difference between the LX FA-1 and the K-1 is a little less shocking. Some other random observations (not spec based): To me the Super A is noticeably smaller than the LX but is still very usable. I think the Super A must be much brighter than the K-5 for example. I can't see any difference between the ME Super and the LX FA-1 even though the ME Super is somewhat smaller. I am hoping for a difference between the LX and the K-1 that is similar to the difference between LX and the Super A. Based on the calculations here and my own, it should be close-ish. Originally posted by stevebrot Added: A bit of trivia...a 1x viewfinder may be used with both eyes open since the magnification is the same as unaided eye. With rangefinder cameras having such (rare), this is a distinct advantage in that it allows the photographer use of their peripheral vision. I have done this with the LX FA-1 and a 50mm lens and it worked for me.

03-10-2016, 08:40 PM	#27
LesDMess Pentaxian Join Date: May 2011 Location: Santa Cruz, CA Photos: Albums Posts: 3,235	Originally posted by RobA_Oz There'll be some (small) transmission loss in a magnifier, but magnification lowers the brightness in proportion to the square of the magnification factor. Given that the viewfinder image in the K-1 will be nearly twice as bright as that in the K-3, a 1.3x magnifier will lower that by a factor of 1.69, so the resultant eyepiece image will be bigger and a little brighter than that of the naked K-3 eyepiece. It isn't all bad. I have a variety of magnifiers that are helpful but all will darken the viewfinder and of course not useful unless tripod mounted like live view. Good or bad it doesn't matter now that the K-1 features are solidified. Hopefully it will be successful enough so we can possibly get these features added to the next one . . .

03-10-2016, 09:33 PM	#28
RobA_Oz Site Supporter Join Date: Nov 2008 Location: Tasmania, Australia Photos: Gallery Posts: 8,200	Originally posted by LesDMess I have a variety of magnifiers that are helpful but all will darken the viewfinder and of course not useful unless tripod mounted like live view. Good or bad it doesn't matter now that the K-1 features are solidified. Hopefully it will be successful enough so we can possibly get these features added to the next one . . . Yes they do, as I said, but if the resultant eyepiece image is both bigger and brighter (even with a magnifier of less than 1.5x), then we can all relax about this, because we're doing better than we have now (which isn't all that bad, really). With my slowly declining eyesight, I need all the luminous flux I can get, especially with an OVF (and, yes, I do have an EVF camera, as well).

03-10-2016, 09:54 PM	#29
LesDMess Pentaxian Join Date: May 2011 Location: Santa Cruz, CA Photos: Albums Posts: 3,235	Originally posted by RobA_Oz Yes they do, as I said, but if the resultant eyepiece image is both bigger and brighter (even with a magnifier of less than 1.5x), then we can all relax about this, because we're doing better than we have now (which isn't all that bad, really). With my slowly declining eyesight, I need all the luminous flux I can get, especially with an OVF (and, yes, I do have an EVF camera, as well). No doubt a reference is needed here but unfortunately my point of reference has no equal in the viewfinder department. I understand that the priority is reliance on autofocus so it is what it is.

03-12-2016, 10:40 AM - 1 Like	#30
gaweidert Loyal Site Supporter Join Date: Mar 2012 Location: Rochester, NY Photos: Gallery Posts: 5,325	I have to admit that I am put off by the .7x magnification of the viewfinder. When I got to this fact when reading the specs it really deflated me. I was hoping for a viewfinder more akin to my Ricoh XRM or Pentax Spotmatic II. I want a split image center surrounded by a micro prism circle for my old eyes, I prefer manual focus to auto focus. Most of the shots with my Tamron 70-210 F2.8 and Pentax 150-450 are made using manual focus. After 45 years of using manual focus lenses I am pretty good at it. But I need a better viewfinder to help me accomplish this. Focus confirmation on my K5 is spotty at best. My k5-IIs is a bit better and the K3 even better, but I want the lens to focus where I want to it and not some computer algorithm. I'm really bummed out about this. Pentax let me down a bit with this camera. It has been a long wait and I had hoped for a true full frame camera in all respects. And yes I was prepared to pay for it. I will probably still get it, but not until after actually handling one. I know I am sounding old and set in my ways, but not all the old ways are the wrong way. On a happier note, the crocuses are in full bloom with it the promise of spring and for me personally, retirement.