Question: Your experience making prints from HMC40 video?

D

Denniscasey

Well-known member
Several questions:

1. Am I right that 1920X1080 video (from HMC40) equates to 2.07 megapixel still (if I were to print a photo from a frame selected from video)?

2. How does HMC40 make a 10.1 megapixel "still" camera shot as they claim in literature--not debating that megapixel claim, just curious?

3. Practically speaking how large a photo could I print on inkjet photo printer from the 2.07 megapixel frame selected from my video and have it look decent? A megapixel vs print size chart from B&H says 2 megapixel camera goves "photo quality" up to 5X7 inch print and is "acceptable" as large as 16X20 inch. I know this is one of those "it depends" questions but to save me a lot of experimenting I just would like some feedback from forum members based on your practical experience.

4. In software if I convert color still frame from video to black and white, could I print larger still photo and have resolution "appear" decent vs color photo?

Background to questions: I just attended a local seminar where a fashion photographer was demonstrating Canon 4K DSLR using "hybrid" workflow. He shot video of model then in software scrubbed through video to pick "best" individual frames--which they called "hybrid" workflow of video/still. Then printed a roughly 24 inch by 30 inch photo on large format Canon printer. Photo looked great to assembled photographers attending. Thinking of all the high res things I have read about 4K video I then understood that the still photo selected from the 4K video was "only" 8 megapixel--about what you get from a low end digital still camera. The B&H chart would say 8 megapixel would be "excellent" quality (I think using 300 ppi) at 20X30 inch which is as high as chart goes.

I actually have used this technique for years (choosing stills from video) but didn't call it "hybrid" workflow, but have only printed small 4X6 inch photos, now thinking of printing larger size prints.
 
NOTE: DPI (Dots Per Inch) is the same as PPI (Pixels Per Inch) for these comments...


(1) Yes, a 1920 x 180 video image is a 2.07MP still image.


(2) The 10.1 megapixel "still" camera shot sucks. I wish Panasonic had not tried to do so high a resolution. The camera shoots GREAT video, but sucks as a still camera. Maybe if they had output the image as 1920x1080 it would look good. Now in all fairness to Panasonic, I never purchased the camera as a still camera; I purchased it because of its GREAT quality video.


(3) The best way to understand this is by looking at the printed DPI (Dots Per Inch) resolution. At 350 DPI, the image looks sharp and even 300 DPI is OK. Drop to around 200 to 250 DPI and the image starts to look soft. Under 200 DPI the image looks fuzzy and lacks detail.

1920 / xxx DPI = horizontal size, 1080 / xxx DPI = vertical size

350 DPI = 5.5" x 3.1"
300 DPI = 6.4" x 3.6"
250 DPI = 7.7" x 4.3"
200 DPI = 9.6" x 5.4"
150 DPI = 12.8" x 7.2" (Very poor sharpness, may look OK from a distance)

So a 5" x 3.5" print would look great, a 6" x 4" would still look OK, and a 7" x 5" would be pushing the limits. If you chose to make a 20" x 16" print, it might look OK from a distance, but as you get up close, the DPI is so low it appears very fuzzy. Even an 10" x 8" print would look fuzzy up close.


(4) Converting to Black & White does not help, because we are looking at the same DPI.


(5) "Then printed a roughly 24 inch by 30 inch photo on large format Canon printer" Assuming that the resolution of the camera was 4096 x 2048, 4096 / 200 DPI = 20.48" and 2048 / 200 DPI = 10.24". I'm sure the 24" x 30" print looked great from a distance, BUT did you see it up close? 4096 / 30" = 136.5 DPI, the image would be very soft up close.



Bob Diaz
 
Bob, thank you for timely and informative reply. It all makes sense. A couple of comments:

(2) "still camera shot sucks" Like you I bought HMC40 for video and have never used still camera feature. Still, if I ever think of using still camera feature, could you describe what aspects of still "suck."

(5) I never thought about vertical and horizontal resolution in terms of still photo print. As you describe it, if I had looked up close at the 24X30 photo they printed I could have seen noticeable difference between vertical (not so good) and horizontal resolution (good). And I did not critically examine the printed photo up close, however the audience of primarily still photo guys were quite impressed with resolution even up close but then many of them were probably shooting with older (although pro-quality) 8 megapixel DSLRs as comparison. Dennis
 
I am still curious how HMC40 (or any video camera) can get/claim 10 megapixel still while generating only 2 megapixel video. Basis for question is whether sensors are capable of much higher resolution video with software change? Dennis
 
When I say the still camera shots from the HMC40 sucks, they have taken what is really 2MP and tried to up-res it to 10MP. That makes the image noise go off the charts and the image is fuzzy. My cheap $99 Canon PowerShot A1200 takes better still images.

Right now it's night, if I remember during the day, I'll take a shot outside to show you.


Bob Diaz
 
BobDiaz said:
When I say the still camera shots from the HMC40 sucks, they have taken what is really 2MP and tried to up-res it to 10MP. That makes the image noise go off the charts and the image is fuzzy. My cheap $99 Canon PowerShot A1200 takes better still images.

Right now it's night, if I remember during the day, I'll take a shot outside to show you.


Bob Diaz[/QUOTE

Sounds like yet another case of advertising hyperbole far exceeding reality--for example, by some strange measurement Panasonic might claim a 10 megapixel still photo, but when you actually take a photo you find much lower resolution. Do all video camera manufacturers use a similar "up-res" scheme to claim much higher still camera megapixel (because many do make such claims) from a video camera (in which case buyer beware) or is Panasonic just uniquely bad at the up-res method they use?

In the case of HD video cameras that claim higher still camera resolution are they all taking what are essentially sensors designed for maximum 1920X1080 resolution and trying to use various schemes to pack more of the existing pixels into something resembling a 10 megapixel (in case of HMC40) still photo?
While still cameras like the Canon A1200 you mention start with sensors or hardware designed to truly take a 12.1 megapixel still photo (A1200 resolution)?

Which in turn means there truly is no such thing as a "dedicated" video camera that can take a still photo at any higher resolution than what it offers for video?
On the other hand, would a camera designed to be a still camera (i.e. todays DSLR's as example) but can also take video provide a still photo at advertised megapixel rating (i.e 18 megapixel for the Canon EOS 1d I saw demonstrated)?
Click to expand...
 
Panasonic does offset the (Red & Blue) image sensors with the Green Image sensor. Panasonic says that would give an equivalent of 1920x2 by 1080x2 = 3840 x 2160 resolution or 8.3MP. I consider it a bit of Marketing hype, because it generates 4 MP worth of data, not 8MP worth of data. The 10 MP is a bit of up-scaling or maybe using some of the extra pixels around the edges of the sensor, I can't remember. In order to get a true 10MP, the native mode of the image sensor has to be a true 10 MP.

My Nikon D5100 really does have a 16MP APS-C image sensor and it also shoots 1920x1080 video. The video is scaled down from the image sensor. The most important thing to look at is what is the real resolution of the image sensor. As you can see, marketing and sales love to "puff" the specifications sometimes with misleading claims and that holds true for all companies.

The really small image sensors (1/10" --> 1/1.7") never really resolve the 12MP or higher that the camera maker say it does. Lenses are not sharp enough to get a true 12MP+ image for that small sensor.

Only the bigger Nikon1 CX, Four Thirds, APS-C, and Full Frame 35mm image sensors are large enough to get the true 12MP+ image. Anything smaller is really just a fuzzy 12MP+ image.


Bob Diaz
 
Bob, thank you for informative discussion. It seems I have to learn more about technology than I really want to in order to avoid "lies, damn lies, and advertising hype" (to paraphrase Mark Twain)--or I can seek advice from this forum.

Your comments on sensor size give a good practical starting point when one is shopping for a camera. In my case I was interested in experimenting with depth of field effects I can not get with small sensors of HMC40 so was shopping for bargain price point cameras: (1) Nikon 1 J1 mirrorless is heavily discounted ($400 with two lens) and I could maybe live with what I hear is very slow auto-focus and I would not be out too much if I found "DSLR video" is not for me (I know this is not a DSLR). However, the sensor at 13.2X8.8 mm is probably too small to give good DOF range; (2) the Lumix G6 ($648 one lens) mentioned earlier by Felipe is an option but I wonder if sensor size of 17.3X13 mm is marginal for good DOF range; (3) B&H suggested Sony Alpha NEX-3N ($448 with kit lens) and sensor size 23.5X15.6 --the APS-C you mention.

Felipe wanted to match HMC40 video "look" , but for my use that is not a high priority. I have also read enough to know there are many pitfalls in using these "still" cameras for video including I think many DSLR do not let you view video while taking it--hence the advent of the Mirrorless camera??

These cameras will clearly not be suitable for most of the video I take (race cars going fast where I need good AF and wide DOF), but for scenery and "still" type content I would like to experiment with DOF range.
 
I consider the Nikon 1 CX sensor the absolute "ideal" minimum size for a camera sensor. Yes, cameras can be built with smaller sensors, but the lenses aren't sharp enough to resolve the high resolution details.

The micro 4/3s image sensor is a much better choice because of the larger sensor size AND wider selection of equipment, like lenses. I know a number of people who use and love their micro 4/3s cameras.

The APS-C sensors are even bigger and I love the results I get from my Nikon D5100 camera. Both Nikon and Canon produce very good cameras using APS-C image sensors.

Beyond that are the full frame image sensors that are really wonderful, BUT the cost is very high; starts at about $2,000 for just the body and the lenses cost a lot more than the DX lenses for APS-C cameras.

There are people who will swear their still camera is the only one to buy, but this is a very subjective choice. What is ideal for one, may not be ideal for another person.



Bob Diaz
 
It's the DPI that kills you on frame grabs from video. It's not even remotely close enough for a good print of any real size. Video = 72 dpi, Photo = 300 plus on the low end.
 
BobDiaz said:
I consider the Nikon 1 CX sensor the absolute "ideal" minimum size for a camera sensor. Yes, cameras can be built with smaller sensors, but the lenses aren't sharp enough to resolve the high resolution details.

The micro 4/3s image sensor is a much better choice because of the larger sensor size AND wider selection of equipment, like lenses. I know a number of people who use and love their micro 4/3s cameras.

The APS-C sensors are even bigger and I love the results I get from my Nikon D5100 camera. Both Nikon and Canon produce very good cameras using APS-C image sensors.

Beyond that are the full frame image sensors that are really wonderful, BUT the cost is very high; starts at about $2,000 for just the body and the lenses cost a lot more than the DX lenses for APS-C cameras.

There are people who will swear their still camera is the only one to buy, but this is a very subjective choice. What is ideal for one, may not be ideal for another person.



Bob Diaz
Click to expand...

Bob, thank you again for very helpful practical information regarding sensor size and related comments. I have to say the CX sensor that comes with the heavily discounted Nikon 1 J1 or J3 cameras may be the "ideal minimum size" for my interest in experimenting with DOF "effects" in video (change what is in focus and what is out of focus by distance). The HMC40 is nicely suited for most of my video work (fast moving race cars far to near and far again as I pan), but for other types of video work the look from being able to change DOF (focus) with iris opening is something I would like to experiment with. At $399 with two lens the J1 looks like something that would give me a good feel for difficulties and looks associated with narrow DOF (vs HMC40) with minimal investment. Dennis
 
jlpskydive said:
It's the DPI that kills you on frame grabs from video. It's not even remotely close enough for a good print of any real size. Video = 72 dpi, Photo = 300 plus on the low end.
Click to expand...

And Bob's October 8 post also illustrates your point showing DPI vs print size for 1920X1080 video.
 
Sensorsizes.png


http://3.static.img-dpreview.com/reviews/nikonv1j1/images/Sensorsizes.png?v=2527

One thing to understand about DOF (Depth Of Field), the mm of the lens and the aperture impact the DOF. Because the Nikon CX image sensor is small compared to the larger sensors, the lens mm must be low to have the same angle of view.

The lower the mm of the lens, the greater the depth of field. At 10mm, it's not easy/possible to get the very shallow DOF. AT 30mm and higher, it's a lot easier to get the shallow DOF.

By stepping up to a Micro 4/3s or better yet, APS-C, the lens mm increases and it's a lot easier to get the shallow DOF.

The Nikon CX Image Sensor is what I consider big enough for higher resolution images, but unless you use telephoto lenses on the Nikon 1, the shallow DOF isn't possible.


Bob Diaz



Shot at 40mm F2.5
 
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Bob, Excellent "tutorial" for me and thank you so much for your patience in helping me understand many of the various inter-relationships impacting DOF/sensor and camera choice. As you guided me I understand why it is important to understand all these things before buying a camera (i.e. don't rely on manufacturer advertising).

From my days with 35 mm camera I did understand aperture importance to DOF, but not how sensor size fit into equation. I am reading several articles on sensor size and lens and focal length (and 35 mm equivalent). At this moment I am a bit befuddled by all involved but have moments of clarity.

By the way, does actual lens size (diameter of lens) have a role to play in all this (although I can't find any statistics in technical specs relating to lens diameter in most cases--just give diameter of threads for filters)? Thanks again, Dennis
 
Felipe, I have never used HMC40 for still photos and from this discussion will not bother to learn how to do that. Did you buy the Lumix G6 (assume it is same as Lumix "DMC" G6) you mentioned in earlier thread and if so what is your evaluation once you have used it? Dennis
 
No Dennis I have too many lenses from Canon, so Is not easy to accept the idea of starting a new collection of lenses, However, I'm sure Lumix is leading image quality in video and doing a great job for still photography.
I really wish I could start a new collection. If I will be you WILL CERTAINLY GO FOR LUMIX, since I understand, YOU DON'T HAVE A BIG CHIP SYSTEM YET.
 
Felipe Henao said:
No Dennis I have too many lenses from Canon, so Is not easy to accept the idea of starting a new collection of lenses, However, I'm sure Lumix is leading image quality in video and doing a great job for still photography.
I really wish I could start a new collection. If I will be you WILL CERTAINLY GO FOR LUMIX, since I understand, YOU DON'T HAVE A BIG CHIP SYSTEM YET.
Click to expand...

I don't have a big chip system and for most of my videos (race cars, scenery) HMC40 deep depth of field is an asset keeping things in focus (particularly in case of fast moving far to near to far distance race cars). I have video friends who were captured by enthusiasm in early days (4 years ago or so) of DSLR video. However, as they were not shooting in studio or controlled environment making movies they got tired of fiddling with focus and missing run and gun shots and went back to video cameras--not a fault with DSLR just did not match their filming environment.

However, there are times when I would like the ability to choose what is in focus and what is blurred and so began looking for inexpensive camera I could "experiment" with. Coincidentally I saw an ad for heavily discounted Nikon 1 J1 for $399 with 10-30mm lens and 30-110 mm lens included. I knew this would not give high quality results for what I wanted to do, but at that price I thought it might give me a "feel" for the DOF look and I lost very little if I did not like working with that type camera. In turn that launched me into trying to understand sensor size impact on camera performance and many thanks to Bob's tutorials I understand Nikon 1 J1 would have been wasted $399 for what I wanted to try out.

I have looked at Lumix G6 (sensor size 17.3X13 mm) and am comparing with Sony Alpha NEX 3 (sensor size 23.5X15.6 mm) as reasonable ways to experiment with "movie look" (DOF technique). However, I have to say this is what comes from having time on my hands at the moment and when I get busy again this desire to experiment might disappear. Dennis
 
Dennis, I make a living out of Photography and Video, and the HMC40, will stay in my bag until she would get broken if that ever happens, and then will go to repair TO STAY WITH ME AGAIN.
Big chip is when you need shallow DOF, or high performance in low light, at the same time you can not work as fast as small chip, or some times you need deep DOF.
One great point from the G6 is that has minimum Moire aliasing, compared to Sony or Canon, besides do great Photography and size is very convenient .
I was about to buy it but to start again with lenses was not a great idea, For Canon you have to buy a very expensive anti aliasing filter, and Sony has not a solution yet for this problem , only
buying a proper video camera no a Stills camera. This G6 is the being compared with Canon Mark III, Check you tube or Google G6 VS Canon Mark III. GO FOR IT
 
Felipe, I don't doubt good advice about the G6. However, as this is a hobby with me (although I take it seriously), the GO FOR IT may require some more thought.
Best Regards, Dennis
 
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