Verizon FiOS HDTV - Page 625 - AVS Forum | Home Theater Discussions And Reviews
Baselworld is only a few weeks away. Getting the latest news is easy, Click Here for info on how to join the Watchuseek.com newsletter list. Follow our team for updates featuring event coverage, new product unveilings, watch industry news & more!


Forum Jump: 
 37Likes
Reply
 
Thread Tools
post #18721 of 18742 Old 07-15-2015, 06:36 AM
AVS Addicted Member
 
John Mason's Avatar
 
Join Date: Jul 2000
Location: New York, NY
Posts: 10,770
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked: 31
Quote:
Originally Posted by jrref View Post
Does anyone know what the resolution is being transmitted on HBO and Showtime series such as Ray Donovan and Masters of Sex for example, on FiOS. Is it me or is it not as sharp as it used to be? Sometimes on dark scenes it really looks like the source is compressed. Other times on regular broadcast TV, the picture is excellent. I know the STB is sending 1080P but i'm talking about the source. Maybe i'm watching too much streaming TV such as Netflix?
It's fairly easy to measure the effective or viewable resolution. Just use a test Blu-ray (or another multiburst pattern source) and this technique of comparing resolution line widths. The link compares two Blu-ray images, with their higher bit rate and crisper detail, and only one 1080i golf broadcast via FIOS. But the maximum visible effective resolution from any source is possible.


You have to be careful to use the right multiplier for rez per picture width: A 16X9 HD standard broadcast is 1.78 while a 4X3 image is only 1.33 times the measured resolution for its finest visible details. You couldn't use ~2.40 for a movie with thick black bars on your 16X9 1080p screen because it can't display more than 1920 pixels horizontally, unlike many movie-theater projectors/screens. I used 1.84 as a multiplier for the Blu-ray movie I tested, which results, math-wise at least, in a higher effective resolution than using only 1.78 max for my 65" Panasonic plasma pro monitor. Other opinions on that?


Tried measuring the max effective resolution of another movie that should provide excellent details, but didn't seem to. Movies, of course, sometimes contain 'artistic' filtering and other techniqes, such as defocusing, that reduce fine details. 24-fps capture also greatly cuts temporal resolution.


I've occasionally measured other fine details with my small plastic millimeter ruler from the screen, but max readings--not surprisingly due to standard digital processing--are similar to the golf-course-detail reading outlined in my linked testing (above). There are other methods of measuring the full spectrum of effective resolution using a computer or other costly hardware, as the sublink in this display-calibration post outlines.


Also noticed an improvement in PQ when switching to FIOS from TWC several years ago (and posted here about it). That was well before they began putting 3 channels rather than 2 within 256-QAMs (AIUI}. Have noticed a few horrendous fine-detail breakups recently on a few channels when motion is involved, but haven't seen this on most channels. Since fine static details also disappear before/with such breakups, perhaps effective rez measurements, comparing vertically oriented details (for horizontal resolution) with known multiburst resolutions or other test patterns, such as 'trumpet-shaped' cones with gradually converging B&W lines, will reveal the sorry results of not using the incredible full-bandwidth potential of optical fibers. -- John

Last edited by John Mason; 07-15-2015 at 07:06 AM. Reason: typo
John Mason is online now  
Sponsored Links
Advertisement
 
post #18722 of 18742 Old 07-15-2015, 02:25 PM
AVS Club Gold
 
aaronwt's Avatar
 
Join Date: Aug 2001
Location: Northern VA(Woodbridge)
Posts: 23,449
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1763 Post(s)
Liked: 1036
Quote:
Originally Posted by jrref View Post
Does anyone know what the resolution is being transmitted on HBO and Showtime series such as Ray Donovan and Masters of Sex for example, on FiOS. Is it me or is it not as sharp as it used to be? Sometimes on dark scenes it really looks like the source is compressed. Other times on regular broadcast TV, the picture is excellent. I know the STB is sending 1080P but i'm talking about the source. Maybe i'm watching too much streaming TV such as Netflix?
It doesn't help that FIOS takes the original H.264 signal and converts it to MPEG2. If they would have switched everything to H.264 then we could view them without being bastardized.
jrref likes this.

53TB unRAID2--38TB unRAID3--33TB unRAID1a
LED DLP
XBL/PSN: WormholeXtreme
aaronwt is offline  
post #18723 of 18742 Old 07-15-2015, 10:50 PM
Member
 
GCAVS's Avatar
 
Join Date: Nov 2012
Posts: 53
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Liked: 12
Quote:
Originally Posted by jrref View Post
Does anyone know what the resolution is being transmitted on HBO and Showtime series such as Ray Donovan and Masters of Sex for example, on FiOS. Is it me or is it not as sharp as it used to be? Sometimes on dark scenes it really looks like the source is compressed. Other times on regular broadcast TV, the picture is excellent. I know the STB is sending 1080P but i'm talking about the source. Maybe i'm watching too much streaming TV such as Netflix?
You are asking the wrong question.

But to answer your question, Showtime is send out at 1920x1080i resolution from the source and the STB outputs it in your house at the same resolution.
GCAVS is offline  
post #18724 of 18742 Old 07-16-2015, 06:21 AM
Senior Member
 
Join Date: Nov 2014
Posts: 491
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 362 Post(s)
Liked: 148
Quote:
Originally Posted by GCAVS View Post
You are asking the wrong question.

But to answer your question, Showtime is send out at 1920x1080i resolution from the source and the STB outputs it in your house at the same resolution.
Thanks, that is what I was looking for but I wonder why it doesn't look as sharp as other 1920x1080i content on some of the regular channels. Maybe it's the filming of the shows themselves?

John
HU9000 / SEK-3500
Marantz 7009
Ohm Walsh Speakers
jrref is online now  
post #18725 of 18742 Old 07-16-2015, 07:23 AM
AVS Special Member
 
dsskid's Avatar
 
Join Date: Nov 2002
Location: Long Island, NY
Posts: 3,077
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 230 Post(s)
Liked: 240
Quote:
Originally Posted by jrref View Post
Thanks, that is what I was looking for but I wonder why it doesn't look as sharp as other 1920x1080i content on some of the regular channels. Maybe it's the filming of the shows themselves?
Check your settop sharpness settings. Perhaps there are different from what they were before.

ISF Calibrator
Samsung PN64F8500
Pioneer Kuro Elite Pro-111FD
Pioneer Kuro BDP-320
Displays are like 100% cotton t-shirts. Always buy a size larger than you think you'll need, as they tend to shrink over time.
dsskid is offline  
post #18726 of 18742 Old 07-16-2015, 07:26 AM
AVS Special Member
 
davehancock's Avatar
 
Join Date: Jan 2002
Location: Hamburg, NY (near Buffalo)
Posts: 5,544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Liked: 55
Quote:
Originally Posted by GCAVS View Post
But to answer your question, Showtime is send out at 1920x1080i resolution from the source and the STB outputs it in your house at the same resolution.
Not necessarily: the STB output resolution depends on the Video Format settings on the STB, It is entirely possible that the 1080i signal could be output at 480i if the settings called for it.

Dave Hancock
davehancock is online now  
post #18727 of 18742 Old 07-16-2015, 07:34 AM
AVS Special Member
 
davehancock's Avatar
 
Join Date: Jan 2002
Location: Hamburg, NY (near Buffalo)
Posts: 5,544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Liked: 55
Quote:
Originally Posted by jrref View Post
Thanks, that is what I was looking for but I wonder why it doesn't look as sharp as other 1920x1080i content on some of the regular channels. Maybe it's the filming of the shows themselves?
I think that (the filming) is the real issue. Each "film" (they really don't use much actual "film" these days) director may go for a unique "look" and render the video that way.

Dave Hancock
davehancock is online now  
post #18728 of 18742 Old 07-16-2015, 07:49 AM
Senior Member
 
Join Date: Nov 2014
Posts: 491
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 362 Post(s)
Liked: 148
Quote:
Originally Posted by davehancock View Post
I think that (the filming) is the real issue. Each "film" (they really don't use much actual "film" these days) director may go for a unique "look" and render the video that way.
Yes I used the work "filming" loosely
So I have my Quantum STB video settings to 1080P which is the highest and I've adjusted the sharpness and all the other settings on the TV. Don't get me wrong but the picture watching HBO and Showtime looks soft to me compared to CNN, NBC or CBS for example. It's almost as if they are using different resolution cameras.


I wish someone here knew how all this works. For example the color saturation, sharpness, etc varies from channel to channel. I though there were transmission standards set a while back on all these parameters.

John
HU9000 / SEK-3500
Marantz 7009
Ohm Walsh Speakers
jrref is online now  
post #18729 of 18742 Old 07-16-2015, 08:35 AM
AVS Addicted Member
 
John Mason's Avatar
 
Join Date: Jul 2000
Location: New York, NY
Posts: 10,770
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked: 31
Quote:
Originally Posted by jrref View Post
Yes I used the work "filming" loosely
So I have my Quantum STB video settings to 1080P which is the highest and I've adjusted the sharpness and all the other settings on the TV. Don't get me wrong but the picture watching HBO and Showtime looks soft to me compared to CNN, NBC or CBS for example. It's almost as if they are using different resolution cameras.


I wish someone here knew how all this works. For example the color saturation, sharpness, etc varies from channel to channel. I though there were transmission standards set a while back on all these parameters.
Had the same questions in 2000 when I joined the forums. After reading hundreds of tech papers, forum posts, and articles on HD resolution and 'sharpness' since then, last year I finally got around to actually measuring differences as outlined above. Apologies if it seems too obscure. Haven't read about anyone else trying it either...yet .


Didn't post the Showtime format resolution versus actual or effective resolution because that's the crux of the whole issue. For those not understanding the terms it may require studying until the light bulb goes on--as it did with me. Have a Notepad folder with hundreds of AVSforum links on the topic, many with tech- paper sublinks, and can post some of them if anyone is unclear about specific areas. -- John
jrref likes this.

Last edited by John Mason; 07-24-2015 at 06:34 AM. Reason: typo
John Mason is online now  
post #18730 of 18742 Old 07-16-2015, 09:10 AM
Member
 
ctbarker32's Avatar
 
Join Date: Mar 2005
Location: Kensington, MD
Posts: 52
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 10
Ray Donovan Fios broadcast specs

Quote:
Originally Posted by jrref View Post
Does anyone know what the resolution is being transmitted on HBO and Showtime series such as Ray Donovan
This is a data dump concerning the latest Ray Donovan episode (S03E01):

Quote:
General
ID : 1 (0x1)
Complete name : F:\Videos\Ray Donovan S01E01 The Kalamazoo.ts
Format : MPEG-TS
File size : 5.23 GiB
Duration : 1h 1mn
Overall bit rate mode : Variable
Overall bit rate : 12.1 Mbps
Movie name : Ray Donovan: The Kalamazoo
Law rating : TV-MA (LS)

Video
ID : 256 (0x100)
Menu ID : 1 (0x1)
Format : MPEG Video
Format version : Version 2
Format profile : Main@High
Format settings, BVOP : Yes
Format settings, Matrix : Default
Format settings, GOP : Variable
Codec ID : 2
Duration : 1h 1mn
Bit rate mode : Variable
Bit rate : 11.1 Mbps
Maximum bit rate : 64.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.179
Stream size : 4.80 GiB (92%)

Audio
ID : 100 (0x64)
Menu ID : 1 (0x1)
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : 129
Duration : 1h 1mn
Bit rate mode : Constant
Bit rate : 384 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Delay relative to video : -1s 52ms
Stream size : 170 MiB (3%)
Language : English
This is from a file capture in native (unmolested) format using an HDHomeRun Prime with cablecard.

I will note that when I play back the file using an Oppo BDP-93, that the playback is noticeably superior to when viewed with the Fios Motorola boxes. There are still very noticeable macro-blocking observed presumably due to the H.264 to MPEG conversion others have mentioned.

-CB
ctbarker32 is offline  
post #18731 of 18742 Old 07-16-2015, 09:23 AM
AVS Special Member
 
davehancock's Avatar
 
Join Date: Jan 2002
Location: Hamburg, NY (near Buffalo)
Posts: 5,544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Liked: 55
Quote:
Originally Posted by jrref View Post
Yes I used the work "filming" loosely
So I have my Quantum STB video settings to 1080P which is the highest and I've adjusted the sharpness and all the other settings on the TV. Don't get me wrong but the picture watching HBO and Showtime looks soft to me compared to CNN, NBC or CBS for example. It's almost as if they are using different resolution cameras.


I wish someone here knew how all this works. For example the color saturation, sharpness, etc varies from channel to channel. I though there were transmission standards set a while back on all these parameters.
All digital camera's in use today are 1080 x 1920 or higher (4K cameras are now pretty much standard) - even when the network is 720p (ABC, Fox, ESPN, etc). For HDTV there are certainly standards today for color, saturation, etc. (BTW: Is your set "calibrated" to those standards?) that are uniform for all TV (broadcast, cable, or satellite). But I think that you are basically talking about the "look" that the program's director (NOT the network) is trying to convey.

An example of this is the "Live TV" (often called the "Soap Opera Effect") vs the "Film" look. (I get into raging arguments with my Son over this.) Traditionally the "Film" look looks "softer" than the "live" look. That is intentional. Many of the programs on network TV ("The Good Wife" on CBS is one example) for for the "film" look, largely because those programs have been traditionally shot on film. As HBO largely shows movies, their stuff tends towards the "film" look.

Perhaps the most influential item in the "look" of a piece is the lighting: For a sharp look lights are placed to create lots of highlights. A dark atmosphere is created by not using fill lights - so there are lots of shadows. By not having lots of shadows and highlights, the picture looks "soft".

There also is a stage in production where the color is manipulated (by the colorist) to, first be uniform from shot to shot, and to achieve the desired "look".

Dave Hancock
davehancock is online now  
post #18732 of 18742 Old 07-16-2015, 10:06 AM
AVS Special Member
 
dcowboy7's Avatar
 
Join Date: Nov 2007
Location: Pequannock, NJ
Posts: 5,679
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Liked: 169
Love the soap opera look.

Watching game of thrones bluray on my 4k 240hz motionflow high is like looking out a window at something actually happening right now....sweet.

Yea showtime is just bad - NFLN & showtime both show the exact same show "inside the nfl" yet it looks alot cleaner/sharper on NFLN than showtime.

dcowboy7 is offline  
post #18733 of 18742 Old 07-16-2015, 01:28 PM
Senior Member
 
Join Date: Nov 2014
Posts: 491
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 362 Post(s)
Liked: 148
Quote:
Originally Posted by dcowboy7 View Post
Love the soap opera look.

Watching game of thrones bluray on my 4k 240hz motionflow high is like looking out a window at something actually happening right now....sweet.

Yea showtime is just bad - NFLN & showtime both show the exact same show "inside the nfl" yet it looks alot cleaner/sharper on NFLN than showtime.
OK that's a good example that I forgot about. Game of Thrones is very sharp when I watch it on HBO, even sharper on Netflix.
And yes my TV is calibrated to Rec.709.


So as you said it's probably the way they are shooting it.


It's kind of a shame because when I rent a new movie, I usually rent from Vudu and stream it because it's sharper than if I rent and watch it on FiOS. FiOS has the capability but they need to figure out what they are going to do, to manage all of the exploding content.

John
HU9000 / SEK-3500
Marantz 7009
Ohm Walsh Speakers
jrref is online now  
post #18734 of 18742 Old 07-20-2015, 07:26 AM
Senior Member
 
mdviewer25's Avatar
 
Join Date: Jan 2006
Location: Capitol Heights, MD
Posts: 463
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 10
Not sure if it was posted here but for some reason Verizon has moved Up from 224 to 238. When you try to type in 224 it goes to 223 GAC. So if you're looking for Growing Pains, 7th Heaven, Touched by an Angel, Judging Amy, or The Parkers tune to Ch. 238

HD DVD = 102
BD = 45
mdviewer25 is offline  
post #18735 of 18742 Old 07-24-2015, 01:20 AM
Member
 
LEVEL4's Avatar
 
Join Date: Feb 2008
Location: Los Angeles, CA USA
Posts: 194
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
Liked: 15
There are a myriad of variables which affect apparent sharpness at the final distribution point, but a significant measure of a given image's look is determined at acquisition:

1.) CNN, local HD news, etc. is acquired a 1/60th of a second (e.g., 1080p60). Dramatic series are typically acquired at 1/48th of a second, either when using Super35-format digital cine cameras (e.g., Arri Alexa, RED, Sony F65, etc.), or a 180-degree shutter-angle when using a 35mm motion picture film camera. Part of the decrease in apparent sharpness of "filmic" content is due to greater subject motion-blur from the the longer exposure times used in dramatic acquisition.

2.) Traditional video acquisition (CNN, local HD news, etc.) using 2/3" ENG cameras typically employ a "snappy" characteristic curve (tone curve), often with a slightly enhanced in-camera sharpness profile enabled. Dramatic acquisition often employs "softer" characteristic curves with shallower gamma, a smoother toe/shoulder, and more subtle knee roll-off. The camera's specific characteristic curve is determined by the DP, DIT (digital imaging technician), and director at the time of acquisition (but only as a LUT if acquiring RAW), and is typically further modified in post-production (e.g., color-grading, digital intermediate, transfer, etc.).

3.) Also, the frame-rate is higher in traditional broadcast acquisition, providing greater temporal resolution for "video-acquired" assets, as opposed to "digital cinema" electronic acquisition and 35mm motion picture film acquisition (e.g., 60p- vs. 24p-acquisition frame-rates).

4.) The smaller sensor size (2/3") used in both studio and ENG video cameras also inherently produces more apparent depth-of-field (more of the foreground and background appears in-focus), whereas dramatic production more commonly employs shallow-focus techniques for dramatic/aesthetic effect, which is much easier to achieve when using larger sensors (e.g., Super35, APS-C, 24mm x 35mm, etc.).
John Mason and UnnDunn like this.

FiOS Motorola VMS1100 | Sony DA5300ES | Sony 75W850C | FireTV | Roku3 | PS4 Destiny
FTTH | GbE | POTS

Last edited by LEVEL4; 07-24-2015 at 02:11 AM.
LEVEL4 is offline  
post #18736 of 18742 Old 07-24-2015, 05:32 AM
Senior Member
 
Join Date: Nov 2014
Posts: 491
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 362 Post(s)
Liked: 148
Quote:
Originally Posted by LEVEL4 View Post
There are a myriad of variables which affect apparent sharpness at the final distribution point, but a significant measure of a given image's look is determined at acquisition:

1.) CNN, local HD news, etc. is acquired a 1/60th of a second (e.g., 1080p60). Dramatic series are typically acquired at 1/48th of a second, either when using Super35-format digital cine cameras (e.g., Arri Alexa, RED, Sony F65, etc.), or a 180-degree shutter-angle when using a 35mm motion picture film camera. Part of the decrease in apparent sharpness of "filmic" content is due to greater subject motion-blur from the the longer exposure times used in dramatic acquisition.

2.) Traditional video acquisition (CNN, local HD news, etc.) using 2/3" ENG cameras typically employ a "snappy" characteristic curve (tone curve), often with a slightly enhanced in-camera sharpness profile enabled. Dramatic acquisition often employs "softer" characteristic curves with shallower gamma, a smoother toe/shoulder, and more subtle knee roll-off. The camera's specific characteristic curve is determined by the DP, DIT (digital imaging technician), and director at the time of acquisition (but only as a LUT if acquiring RAW), and is typically further modified in post-production (e.g., color-grading, digital intermediate, transfer, etc.).

3.) Also, the frame-rate is higher in traditional broadcast acquisition, providing greater temporal resolution for "video-acquired" assets, as opposed to "digital cinema" electronic acquisition and 35mm motion picture film acquisition (e.g., 60p- vs. 24p-acquisition frame-rates).

4.) The smaller sensor size (2/3") used in both studio and ENG video cameras also inherently produces more apparent depth-of-field (more of the foreground and background appears in-focus), whereas dramatic production more commonly employs shallow-focus techniques for dramatic/aesthetic effect, which is much easier to achieve when using larger sensors (e.g., Super35, APS-C, 24mm x 35mm, etc.).

Great! thanks for an explanation that makes sense!

John
HU9000 / SEK-3500
Marantz 7009
Ohm Walsh Speakers
jrref is online now  
post #18737 of 18742 Old 07-24-2015, 06:25 AM
AVS Addicted Member
 
John Mason's Avatar
 
Join Date: Jul 2000
Location: New York, NY
Posts: 10,770
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked: 31
Quote:
Originally Posted by LEVEL4 View Post
4.) The smaller sensor size (2/3") used in both studio and ENG video cameras also inherently produces more apparent depth-of-field (more of the foreground and background appears in-focus), whereas dramatic production more commonly employs shallow-focus techniques for dramatic/aesthetic effect, which is much easier to achieve when using larger sensors (e.g., Super35, APS-C, 24mm x 35mm, etc.).
Agree, nice write-up, LEVEL4. Could you also outline, simply, why 2/3" sensors deliver better DoF than ~35mm-size sensors in digital-cinema cameras? Spent a while going through an old photography text recently that had a great explanation about film/lenses and DoF (to help write a comment on Sony's new 4k, 2/3-inch-RGB sensors, 4300 camera ), but couldn't find the section. Thanks. And there's also those 'nasty' (IMO) detail-robbing lens filters, the subject of numerous older threads here, that DOPs insist upon. :-). -- John
John Mason is online now  
post #18738 of 18742 Old 07-24-2015, 05:23 PM
Member
 
LEVEL4's Avatar
 
Join Date: Feb 2008
Location: Los Angeles, CA USA
Posts: 194
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
Liked: 15
Quote:
Originally Posted by jrref View Post
Great! thanks for an explanation that makes sense!
Thanks!

FiOS Motorola VMS1100 | Sony DA5300ES | Sony 75W850C | FireTV | Roku3 | PS4 Destiny
FTTH | GbE | POTS
LEVEL4 is offline  
post #18739 of 18742 Old 07-25-2015, 12:34 AM
Member
 
LEVEL4's Avatar
 
Join Date: Feb 2008
Location: Los Angeles, CA USA
Posts: 194
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
Liked: 15
Quote:
Originally Posted by John Mason View Post
Agree, nice write-up, LEVEL4. Could you also outline, simply, why 2/3" sensors deliver better DoF than ~35mm-size sensors in digital-cinema cameras?
Thanks! Strictly speaking, smaller sensors don't actually produce greater depth-of-field. The two variables which affect depth-of-field are: 1.) Subject-to-camera distance (the closer the focus distance, the shallower the depth-of-field), and 2.) Aperture (the larger the aperture [lower, numerically], the shallower the depth-of-field).

While those two conditions are clear, the reason why smaller sensors appear to yield more depth-of-field is less intuitive. Take a crop-frame DSLR like a Nikon D3300. The "crop-factor" of its APS-C sized sensor is 1.5x, when compared to a full-frame sensor such as the one in Nikon's flagship professional body, the D4 (approximately 24mm x 36mm). This crop-factor means that with any given lens, it will have an apparent field-of-view 1.5x that of the lens' focal length. For example, a 50mm lens mounted on a crop-frame body would have a field-of-view equivalent to what a 75mm lens would look like on a full-frame body (i.e., 50mm x 1.5 = 75mm).

Now, if using that same 50mm lens on both cameras, and if the desired image is of, say, an apple which fills the screen, the crop-frame camera would necessarily have a greater subject-to-camera distance, whereas the full-frame camera would have a shorter subject-to-camera distance in order to achieve the same image size. Therefore, recalling that reduced subject-to-camera distance results in shallower depth-of-field, if using the same lens on cameras with different-sized sensors, while attempting to achieve the same image size (i.e., magnification), this results in a more shallow-focus image when that lens is used on the larger-sized sensor.

FiOS Motorola VMS1100 | Sony DA5300ES | Sony 75W850C | FireTV | Roku3 | PS4 Destiny
FTTH | GbE | POTS

Last edited by LEVEL4; 07-25-2015 at 12:44 AM.
LEVEL4 is offline  
post #18740 of 18742 Old 07-25-2015, 07:26 AM
AVS Addicted Member
 
John Mason's Avatar
 
Join Date: Jul 2000
Location: New York, NY
Posts: 10,770
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked: 31
Quote:
Originally Posted by LEVEL4 View Post
Thanks! Strictly speaking, smaller sensors don't actually produce greater depth-of-field. The two variables which affect depth-of-field are: 1.) Subject-to-camera distance (the closer the focus distance, the shallower the depth-of-field), and 2.) Aperture (the larger the aperture [lower, numerically], the shallower the depth-of-field).

While those two conditions are clear, the reason why smaller sensors appear to yield more depth-of-field is less intuitive. Take a crop-frame DSLR like a Nikon D3300. The "crop-factor" of its APS-C sized sensor is 1.5x, when compared to a full-frame sensor such as the one in Nikon's flagship professional body, the D4 (approximately 24mm x 36mm). This crop-factor means that with any given lens, it will have an apparent field-of-view 1.5x that of the lens' focal length. For example, a 50mm lens mounted on a crop-frame body would have a field-of-view equivalent to what a 75mm lens would look like on a full-frame body (i.e., 50mm x 1.5 = 75mm).

Now, if using that same 50mm lens on both cameras, and if the desired image is of, say, an apple which fills the screen, the crop-frame camera would necessarily have a greater subject-to-camera distance, whereas the full-frame camera would have a shorter subject-to-camera distance in order to achieve the same image size. Therefore, recalling that reduced subject-to-camera distance results in shallower depth-of-field, if using the same lens on cameras with different-sized sensors, while attempting to achieve the same image size (i.e., magnification), this results in a more shallow-focus image when that lens is used on the larger-sized sensor.
Thanks again. That should save me lots of time hunting for an answer that doesn't exist, strictly speaking as you say. -- John
John Mason is online now  
post #18741 of 18742 Old 07-25-2015, 12:13 PM
Member
 
LEVEL4's Avatar
 
Join Date: Feb 2008
Location: Los Angeles, CA USA
Posts: 194
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
Liked: 15
Quote:
Originally Posted by John Mason View Post
Thanks again. That should save me lots of time hunting for an answer that doesn't exist, strictly speaking as you say. -- John
Sure. I should add that as the sensor becomes smaller, the focal length required to obtain similar fields-of-view that are typical of those used on full-frame DSLRs or large-format digital cine cameras, also becomes smaller, while the lens' physical size also decreases.

So, when dealing with very small sensors (such as those used in compact point-and-shoot cameras and cell-phone cameras), the lens' focal lengths begin to get very "short." For example, while a 20mm lens on a Super35-format digital cine camera produces a wide-angle of view (30mm full-frame equivalent), an iPhone6 with its tiny 1/2.6" sensor uses about a 4mm lens to achieve a similar angle-of-view due to its large crop-factor (approximately 7.5x). Also, with smaller lenses, the actual size of the aperture (regardless of the lens' marked f/number) is physically much smaller than the aperture openings on lenses made for larger sensors. This inherent decrease in aperture size in smaller lenses further increases depth-of-field, and is the principle reason small-sensored cameras are associated with large amounts of depth-of-field.

FiOS Motorola VMS1100 | Sony DA5300ES | Sony 75W850C | FireTV | Roku3 | PS4 Destiny
FTTH | GbE | POTS
LEVEL4 is offline  
post #18742 of 18742 Old Today, 07:02 AM
Senior Member
 
timewaster's Avatar
 
Join Date: May 2001
Location: New York,NY,10003
Posts: 271
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
anyone using fios in NYC?
I seem to have lost FX (channel 53) and FXHD (channel 553) a few weeks ago.
I am using a cablecard with Tivo Roamio.
Now when I tune to these channels, i get a not authorized msg.
I called verizon and they said I should be getting this channel so wanted to see if others were affected by this.
timewaster is online now  
Sponsored Links
Advertisement
 
Reply HDTV Programming



Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off