Author: Kevin

How to share your mobile device (smartphone, tablet) video/audio to a TV screen

How to share your mobile device (smartphone, tablet) video/audio to a TV screen

Kevin

Many devices today support sharing video and audio to a separate device. Getting it to function can sometimes be simple and sometimes be difficult, depending upon the specific devices.  Sharing from an Apple iPhone (or iPad) to Apple TV should be easy to setup.  Sharing from a Samsung smartphone/tablet to a Samsung smart TV should also be easy to setup.  But the word “should” doesn’t always mean much.

Wired connection using an HDMI cable

Regardless of whether the TV is a “smart TV” or not, you may be able to connect the mobile device to the TV via an HDMI cable, set your TV to use the HDMI input rather than television. However not every smartphone or tablet supports this. For example, Motorola smartphones apparently do not support it.

Current iPhone models have a Lightning port and you will need a Lightning-to-Digital-AV-Adapter.  (Rumor suggests that upcoming new iPhone models will instead have a USB-C port.)

An Android phone probably has a USB port. (Specifically, newer models within the past 18 months will have USB-C.) You will need a USB-to-HDMI adapter … or possibly an MHL cable, but most devices do not support MHL.

Wirelessly connect a smartphone/tablet/computer to a television

If a TV is not a smart TV but does have HDMI input ports, you can attach an external device to the TV which effectively adds “smart” to your dumb TV. Common external devices that support wireless sharing include:
Google Chromecast, EZCast, Apple TV, Samsung AllShare, Amazon Firestick, and Roku.

Using your smartphone/tablet/computer as the sending device and your smart TV as the receiving device, there are two basic requirements:

  • The two devices must be on the same local network (e.g. your home wi-fi).
  • The two must utilize the same stream-casting protocol.

The three dominant protocols today are:  Miracast, Airplay 2, and Google Cast (a.k.a. Chromecast built-in) .  Samsung’s Smart View is based upon Miracast.

Chromecast will not function without an internet connection; this is not true for Miracast and Airplay 2. Miracast is built upon a standard called “Wi-Fi Direct”, allowing two devices to communicate directly rather than over a network. (AirPlay is proprietary, specific to Apple.)

I have an Android tablet that has successfully connected with two different smart TVs, Amazon Firestick, and an audio amplifier; but my smartphone can only connect to one of those four.  The phone supports only Chromecast while three of the other devices support only Miracast. The following table attempts to show such compatibilities and incompatibilities.

Casting

Stream “casting” and “screen mirroring” are two forms of wirelessly sending media (video and/or audio) from one device to another. Although they are different, the term casting may sometimes be loosely misused.

Technically, casting (a.k.a. stream casting) is a feature of a specific application, with support from the mobile device. YouTube, Netflix, Hulu, and iHeartRadio are a few of the apps that support casting.  [Note to some friends using the Zoom videoconferencing app: this does Not support casting but you can certainly use screen mirroring; keep reading.]

Example: On an Android device supporting Chromecast, go to the settings (swipe down from the top of the screen).  Enable: Cast.  That should present a list of available destinations (e.g. a TV). The mobile device will send an invitation to the destination and may display the animated icon (illustrated above).  Then launching the mobile YouTube app, it shows the connected icon (illustrated above) in the title bar at the top of the app.  Upon launching any video within the app, the video and audio are wirelessly cast to the TV.

In the case of a video&audio app such as YouTube, casting to an audio-only device, the video plays on the mobile device as normal while the audio plays from the audio device. I don’t recommend this, as the audio is delayed and no longer synchronized with the video.

Display Mirroring

Display mirroring (a.k.a. screen mirroring) is a feature of your mobile device that wirelessly replicates your local device display on a remote screen (e.g. television).  As this mirrors your entire screen, you can use ANY applications and those apps need not include any special features. (Possibly, you may also be able to use your TV as the source and mirror that to another device, but I cannot think of a scenario where that would be useful.)

The following photo shows the activation of mirroring on a particular model of LG smart TV.  As you can see, the TV has identified that a Galaxy Tablet is nearby and enabled for casting/mirroring.  The tablet may then prompt to authorize the connection, shown in the next photo.

The next photo shows the activation of Screen Mirroring on Amazon Firestick.

Samsung

Smart View is Samsung’s brand of Miracast.  Smart Things is Samsung’s home automation, with the ability to control many smart home devices, including smart TVs.

In the TV on-screen menu, go to Connection Guide and enable screen sharing (screen mirroring).

In the tablet settings, enable SmartView, which should then present a list of available destinations, including the nearby smart TV.  Easy peasy.

In one particular instance, I easily established mirroring from a Samsung tablet to a Samsung smart TV … but it eventually ceased for an entirely unknown reason and would not reactivate. I rebooted the tablet but that did not resolve the problem.  Restarting the TV also did not resolve the problem.  Seeing no resolution, I searched online to see if anyone else had encountered this problem and perhaps offered a solution.

In online discussion forums, a couple of separate people reported difficulty with S6 or S8 smartphones wherein the problem was solved by using the Samsung Smart View app instead of the phone’s built-in settings. However, the Android app store included a note suggesting a different app for connecting with newer model TVs – Samsung  Smart  Things. I installed that and tried it. Although this was also unsuccessful, it did report a useful help message: try unplugging the TV power (and then plug in again). To my surprise, that did resolve the problem.

 

Other protocols

  • Amazon Fling is very similar to Google Cast but never achieved wide acceptance
  • DLNA may be available in older products but not used in newer products
  • Intel WiDi (Wireless Display) was officially discontinued in 2016
  • DIAL (DIscovery And Launch)

Creativity Is Worth The Risk.

Kevin
Hoh Rainforest

“Creativity is a process of discovery. It’s worth the risk. Dream. Dare. Jump.”
– John Paul Caponigro  (artist/photographer)

Interestingly, John Paul wrote this at the END of a list of fears that creative people may face. Allowing oneself to express creativity is commonly risky.  Some folks may fear failure while other folks may fear changes inherent in success.

Just a few from John Paul’s list  ( CreativeFearsList )

  • You’re afraid you’ll be called uninspired.
  • You’re afraid what you do won’t matter to anyone.
  • You’re afraid the reward you receive won’t be worth the financial investment you make.
  • You’re afraid that when compared with someone else’s creation your creation will seem insignificant.

As creatives, we endure a tension between two competing forces. On one hand, we must dance to our own tune (sing your own song), regardless of whether it achieves mass appeal.  On the other hand, art should communicate something to others, so we need to be concerned with the impact of our work upon other people.

If you believe that your creative spark is a gift from above, from the divine, then you should engage and pursue it.  That does not mean you should pursue it recklessly.  (Don’t quit your day job just yet.)  But as each person seeks validation – is my work good or a waste of time? – the first place to seek an answer is from your divine source.

Creatives are commonly at a disadvantage because our initial motivation is not strongly connected to capitalistic success. We’re creative because we just are.  In the words of musician John Lee Hooker, “You’ve got to let that boy boogie woogie, ’cause it’s in him and it has to come out.”

If the thought of NOT pursuing your creative passion feels like misery … then definitely pursue it.  Yes, “it’s worth the risk. Dream. Dare. Jump.”

 

How Many Megapixels Do I Need?

How Many Megapixels Do I Need?

Kevin

Problem #1

A friend had trouble emailing photos from his smartphone. His photos were more than eight megapixels and he was trying to email two dozen of them in a single email. His email did not want to send an email totaling 400 megabytes. The resolution of his smartphone camera captured far more pixels than he needed and the files were … not small.

Problem #2

If you upload a small photo to an online service, particularly social media, that service will likely attempt to enlarge the photo … and you may not like the quality of the result.  While shrinking a photo typically does not have a negative impact on photo quality, enlarging can possibly have undesirable results because the enlarging process is attempting to invent pixels that did not originally exist.

Display on a smartphone

If you primarily look at photos on your phone, then 5 megapixels is more than you need.

Consider the display resolution of some popular smartphones:

  • Google Pixel 3 is 1080 x 2160 … 2.3 MP
  • iPhone X is 1125 x 2436 … 2.7 MP
  • Razor Phone 2 is 1440 x 2560 … 3.6 MP
  • Samsung Galaxy S9 is 1440 x 2960 … 4.2 MP

Print

Printing a photo onto paper is the most demanding application. As a general rule of thumb, high-quality printing requires between 240 to 300 pixels per printed inch. The bigger your print, the more pixels you need.

Example:  A 5-megapixel photo should print well up to 8×10 inches
(8×240) x (10×240) = 4.6 megapixels

Facebook

The recommended upload size is 1,200 × 630 pixels. You can certainly upload a larger photo, but Facebook will automatically shrink it.

Instagram

By design, Instagram favors square photos. You can post a rectangular photo, the Instagram default is a square crop. Upon first uploading your photo, you have an opportunity to undo that crop, but you cannot subsequently edit the photo to change it after your posting is complete.

The recommended size ix 1080 × 1080 pixels. You can certainly upload a larger photo, but Instagram will automatically shrink it.  If you upload a rectangular photo, it will be cropped to width 1080 pixels.

Twitter

Recommended upload size is 1200 × 675 (aspect ratio: 16:9): You can certainly upload a larger photo, but Twitter will automatically shrink it.

Display on a tablet

Consider three tablets.

  • Amazon Kindle Fire HDX 8.9” : 2560 × 1600 pixels, 8:5 aspect ratio
  • Apple iPad 10.2” (2019) : 2160 × 1620 pixels, 4:3 aspect ratio
  • Samsung Galaxy Tab A 10.1” (2019) : 1920 × 1200 pixels, 16:10 aspect ratio

If you size an image 2560×1600, it will display full-screen on the Kindle HDX 8.9” but may seem too large for both the iPad 10.2” and the Galaxy Tab A 10.1”.  Not to worry, the tablet includes the necessary smarts to dynamically make your photo fit the device screen without modifying your stored photo.

You can certainly store photos with higher resolution than the device display; the only consequence is that the photos consume more storage space than is necessary.

eBook, part 1 –  cover photo displayed in the ebook store

For the Kindle store, Amazon recommends 2500 x 1563 pixels.

eBook, part 2 –  photos inside the book

In large part, this comes back tablet display screens. As the Kindle and iPad (described previously) are similar regarding 1600 pixels in the smaller dimension, you might size your photos to 1600 pixels. Amazon recommends twice this, 3200 pixels, but I don’t know why.

Upon uploading your eBook to the Kindle store, your photos will be automatically compressed.  My latest ebook manuscript (with photos) was more than 12 megabytes before submitting, but Kindle compression reduced it to 4 megabytes.

The amount of royalty you earn from each book sale may be reduced because total eBook file size may incur a larger “delivery fee” per individual sale, perhaps fifteen cents per megabyte. An e-book with many high-resolution photos may incur a higher delivery charge and therefore reduce the royalties paid to the author.

 

 

 

One Year After The Fire

One Year After The Fire

Kevin
October 23, 2018; 10:20 A.M.

Mid-October 2018, I photographed Wakefield Massachusetts using an aerial drone.  As the autumn colors were not well developed yet, I returned a week later to make the same photo again.  That’s the first photo here, October 23, 2018.

Some renovation work was in progress that day. You can see scaffolding against the steeple and one of the tall windows is laying on the grass.

In the evening later that day, a lightning storm passed through the area and this presumably sparked the fire that destroyed the First Baptist Church. The next day, I again put the drone in the air to photograph the aftermath of the fire.

Today is the one-year anniversary of that fire, so I returned to again make the same photograph, but without the church.

October 23, 2019; 10:30 A.M.
Outdoor Photography – chasing mother nature

Outdoor Photography – chasing mother nature

Kevin
Rumney Marsh photographed with an aerial drone (sUAS)

I first visited Rumney Marsh in the month of May.  Although I discovered some great photo compositions, the marsh was mostly brown.  Presuming that the grasses would fully transform the landscape into a greener palate, I vaguely planned to return some weeks later. Shown here below is my first image from the May visit:

Rumney Marsh in the month of May

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This year, spring in New England has featured more rain than normal. Dry days are a bit like currency – have to spend them judiciously.  Five or six weeks later I returned to the marsh on a dry day and found the green grasses covered the land, as expected. Unexpectedly, coastal clouds were lingering and the water reflected white sky (not blue sky).

Rumney Marsh (June) under cloudy skies

While that is a nice image, … I had imagined the water reflecting a blue sky. So, I returned later that same day after the clouds cleared away. That final image is shown at the top of this article.

In all three instances, the image required post-processing for HDR, particularly because the buildings on the horizon were too bright. So each of these three instances is a combination of multiple exposures, simply to control the dynamic range of light.

Photo Opportunity – Blooming of the Cherry Trees

Photo Opportunity – Blooming of the Cherry Trees

Kevin
Evening at the tidal basin, Washington D.C.

Flowers blooming on Cherry trees is a harbinger of spring because Cherry trees bloom first, before other flowering trees. While these blooms are a much anticipated spectacle, predicting when the cherry trees will bloom … is difficult business.

From Macon Georgia to Boston Massachusetts, you can visit well-known groves of cherry trees. The trees bloomed in Georgia last week. Unfortunately, I missed it because of car trouble.

The very first blooms appeared in Macon GA around March 10. The very first blooms appeared in Washington D.C. just a few days ago.

The general blooming of Cherry trees in Washington D.C. has not happened yet, but should begin by end of this week. Midweek temperatures this week are still cool with overnight temperatures close to freezing. The current weather forecast tells that the temperature will warm this Thursday. So, blooms should be popping this coming weekend.

At our nation’s capitol, people do actively report the progress of the cherry tree buds. Here’s an update today:
cherry-blossoms-now-at-stage-4-with-peak-bloom-fast-approaching

The best-known location around D.C. is the tidal basin, shown in the photo above.  As you can see in this late-day photo, it can draw a dense crowd. You will not find crowds like this early in the morning.

Options for Displaying a Photo Print

Options for Displaying a Photo Print

Kevin
Canvas print and custom-made frame

Here’s  one of my favorite photographs (from the coast of Maine) printed on canvas and mounted in a custom frame that I designed and constructed. As the print is on canvas rather than paper, there is no glass in front of the print.

As there are many options available for displaying photograph prints, here is a video to share some methods that I have used:

 

Paper

Traditionally, photographs are printed on paper, either a light-sensitive paper or an inkjet paper. Because such a print is typically not durable, the displayed print is protected behind a sheet of glass or acrylic (a.k.a. plexiglass). Furthermore, the print should not be placed directly against the glass/acrylic and the common separator is matboard, with an opening cut in the middle to show the print. The mat also provides visual space around the print, separating it from the frame; consequently, the outermost frame has larger dimension of height and width.
Note: Alternatively, you can use small spacer (instead of matboard) and the frame is then sized to exactly fit the dimensions of the print.

Here’s a previous blog article about making photo prints on paper.
https://www.kevindavisphoto.com/blog/how-to-print-photographs/

A print on paper is either adhered to a backer board or possibly suspended using an archival hinge.  Collectively, the backer board, print, matboard, and glazing (glass or acrylic) are commonly inserted into the frame in one of two ways.  If using a sectional aluminum frame, assemble three sides, slide the materials into the frame, and then attach the fourth piece of the frame.  Any other frame is typically fully assembled first and the materials then inserted from the back side.

Canvas

The print shown here was printed by by Artistic Photo Canvas (APC). Having experienced their very good service and products, I recommend APC.

Canvas prints are commonly stretched around a wood stretcher frame.  The result has a thickness unlike paper prints and that calls for a different type of framing. One common method is called a floating frame. Though this is “L” shaped like a regular picture frame (for paper prints), the foot of the L is behind the print rather than in front. The canvas print is inserted from the front and secured with screws from behind.

The floating frame allows for a gap around the perimeter of the canvas such that the print seems to float within the frame, without touching the frame.  Depending upon the width of the gap, the edges of the canvas may be visible. For the particular print shown at the beginning of this article, I darkened the white sides of the canvas using an oil paint pen, shown here in the photo below.

Use an oil paint pen to darken the edges of a stretched canvas

Aluminum

Unlike a print on paper, which needs to be protected behind glazing, a print on aluminum provides a flat print that is inherently durable and does not need to be protected.

Typically, the cost of an aluminum print is 2.5x to 3.5x the cost of an inket print on paper. I checked ten vendors; the cost of a 20×30 aluminum print ranged from $22 to $140.  I see no reason why some vendors charged more than $100.  Before ordering a print on aluminum, I recommend that you shop around.

Custom Picture Frames

If you’ve ever taken a photo, drawing, or painting to a frame shop, you probably know that framing can be very expensive.  I have sometimes invented my own frames; here’s more information:

https://www.linkedin.com/pulse/20140904014749-11342290-picture-framing-options-including-making-your-own/

 

Image Quality : Mavic 2 Pro vs. (original) Mavic Pro

Image Quality : Mavic 2 Pro vs. (original) Mavic Pro

Kevin
Mavic 2 Pro and the original Mavic Pro

 

The day of the new Mavic 2 release one week ago, numerous sites and YouTube channels already had reviews prepared. DJI had judiciously provided new Mavic 2 drones to people who would do these reviews. I have no intention of rehashing that stuff. I am interested specifically in the camera performance.  Because I am largely interested in image quality, we’re talking about the Mavic 2 Pro, not the Mavic 2 Zoom.  As for video quality, we’ll have to leave that for another day.

For high-quality images, DJI now provides this choice: Phantom 4 Pro, Mavic 2 Pro, Inspire 2 with Zenmuse X5s, Inspire 2 with Zenmuse X7.  The unique value proposition of any Mavic is that it folds down to a size that can fit in a camera bag. A Mavic drone and remote controller requires physical space similar to a DSLR camera body and a zoom lens.

For photographers, is the upgrade worth it, from Mavic Pro to Mavic 2 Pro?
Yes, after brief testing this morning, there is no doubt in my mind.

With the advent of Mavic 2 Pro, the camera difference between Mavic and Phantom has been erased. Both the variable aperture (f/2.8 to f/11) and the sensor resolution (5472×3648) are on par with the pre-existing Phantom 4 Pro and superior to the original Mavic Pro.  Note that this is a 2:3 aspect ratio compared to a 3:4 aspect ratio of Mavic Pro, Mavic 2 Zoom, and Zenmuse X5s.

Note that camera is new and not exactly the same as P4P. DJI bought a majority stake in Hasselblad a couple years ago and this apparently is the first fruits of that partnership. (Yes, DJI essentially owns the legendary Hasselblad company.)

According to the numbers, the angle of view is a bit different, though I did not notice during actual use.  Mavic 2 Pro provides a FOV equivalent to 28mm lens on a full-frame camera. This is narrower than the original Mavic Pro’s equivalent 26mm and narrower than the Phantom 4 Pro’s equivalent 24mm. Despite being less wide angle, vertical lines can still keystone strongly and you may choose to correct for that in post processing.

Here are the problems with Mavic Pro that I hope are improved with Mavic 2 Pro.

  • Dynamic range in the Mavic Pro was not very good. In high-contrast scenes, highlights can easily blow out and/or the shadows block up. To mitigate this, I have sometimes captured multiple RAW exposures and then post-processed for HDR.
  • Using RAW capture, if the highlights do not blow out entirely, the camera still fails to resolve details in the highlights. For example, houses with clapboard siding in full sun – the separation of the clapboards may be entirely absent in the image. This seems surprising to me … if the story is true that the RGB color space has finer granularity in the highlight range compared to the shadow range.
  • Image noise, particularly in shadows. To mitigate this, I have relied upon heavy-handed post-processing. While noise reduction in Adobe Lightroom is very good, there is a price to pay – higher levels of noise reduction can deteriorate details throughout the brightness range.
  • With high magnification, images lack sharpness. In post-processing, I have found it necessary to apply twice as much sharpening compared to my hand-held cameras.
  • Color from RAW images is typically worse than any other camera I have used (except perhaps GoPro Hero3) and the images require heavy-handed post-processing. Of course, RAW images from any camera will always require some degree of post-processing.
  • Blue/red chromatic aberrations. I commonly see this around white baluster railings. Lightroom’s ability to mitigate chromatic aberration typically fails to resolve the problem.

In summary, the Mavic 2 Pro does achieve small improvements in all of these problem areas. So let’s look at some actual images from the new Mavic 2 Pro compared to the original Mavic Pro.

Harbor photographed with both drones

In high-contrast situations such as this scene with white boats and white houses, Mavic 2 Pro still has difficulty retaining detail in the highlights, but is not so bad that it requires HDR techniques to overcome it.  It is still necessary to reduce the exposure by 1/3 stop to protect the highlights (this does not jeopardize shadow details) and also apply highlight reduction in post-processing.

[Click on an image to see the full resolution.]
[Images shown here are all RAW and individually post-processed to the very best of my ability using Adobe Lightroom.]

Detail in highlight areas
Image sharpness

Noise reduction is still necessary but far less than with the original Mavic Pro.

Color of RAW images is much better, requires less correction.

Here’s an example (not a particularly good one) that shows Mavic Pro was unable to resolve the balusters and suffered chromatic aberration.  Mavic 2 Pro did not exhibit either of these problems.

Click on the image to see larger version

 

Finally, a few notes that do not regard image capture.

If you’ve ever fumbled with the gimbal clamp on the original Mavic Pro, or worse yet have forgotten to remove the clamp before powering on the drone, rest assured that the new Mavic 2 Pro does provide an improvement. The gimbal clamp is integrated into the protective dome cover – remove the dome necessarily removes the gimbal clamp.  See the photo below showing both the Mavic Pro and the Mavic 2 Pro.

Gimbal clamp

Unlike the original Mavic Pro, the Mavic 2 includes 8GB on-board memory in addition to a micro SD slot. To access this memory from another device, connect a USB cable (included) to the Mavic 2 USB-C port and turn on power to the Mavic 2. (Remember to remove the gimbal clamp before turning on the Mavic.) After having inserted a micro SD card, the DJI GO app prompted whether to use that instead of the on-board memory.  I am assuming that we must select one or the other and automatic switch-over is not supported, but I don’t know that for certain.

The transmission system between the drone and the controller is theoretically the most robust of any DJI product to date. Mavic 2 utilized second generation Occusync 2.0, while the Phantom line has yet to adopt the Occusync transmission system.  Although Occusync 2.0  reportedly can operate at distances up to five miles, I personally have no need of that.  Increased robustness of the signal is welcome, as I have seen unexplainable video signal loss when using the original Mavic Pro.

Mavic Pro Mavic 2 Pro
Diagonal Size
(Not including propellers)		 335 mm 354 mm
Obstacle avoidance forward, downward forward, backward,
left, right,
downward, upward
Flight time on single
battery charge		 27 min 31 min
Max speed 40 mph 72 kph
Built-in RAM 0 8GB
Cost (first released) $1,000 $1,450
Battery cost $90 $120
Mavic Pro Mavic 2 Pro
Photo ISO range 100-3200 100-6400
Video ISO range 100-1600 100-12800
Lens focal length Equivalent to 26 mm on 35mm full-frame camera Equivalent to 28 mm on 35mm full-frame camera
Lens aperature  f/2.8  f/2.8 – f/11
Max photo resolution 4000×3000 5472×3648
Max video resolution @ 30 fps 4K: 3840×2160 4K: 3840×2160
Max frame rate @ 1080 96 fps 120 fps
Max video bitrate 60 Mbps 100 Mbps
Video compression H.264 H.265
HDR video no yes

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Public Art (on utility boxes)

Kevin
Public art on utility boxes, downtown Peabody MA

Stopping at a coffee shop downtown, I put a quarter in the parking meter.  When I returned, 20 minutes remained on the meter, so I took a short walk.  That’s when I happily discovered art on a utility box … and another … and another.

While I prefer a camera with interchangeable lenses, at times like this I am happy to have a mobile phone with a camera.  My phone-camera is not a great camera, but as the saying goes …  the best camera is the one you have with you.

I must also note that Android / Google Photos includes some photo post-processing functions that I rarely use but did use here.  The leftmost image was badly overexposed.  The problem was very well solved by applying “auto”.

(No, I’m not giving up my big interchangable-lens cameras.)

 

 

 

 

Light Sources for Photography

Light Sources for Photography

Kevin

In a recent on-line discussion, someone offered a very confused (wrong) explanation of electronic flash options for photographic lighting.   To straighten out the confusion, here’s a very brief overview of light sources for photography.

Light sources that strobe/flash

  1. Studio strobe : Generally requires power from an AC wall-outlet
    More power (more than batteries) enables more light and shorter recycle time.
    Most studio strobes include a modeling light, which is a low-power continuous light that helps a photographer setup the light.
  2. Monolight (a.k.a monoblock) : Self-contained studio strobe (does not have an external power pack).  Some have an option to operate from battery.
  3. Speedlight : a small battery-powered strobe with hot shoe; can be used on or off camera
  4. Small strobe like a Speedlight but without hot shoe … is there a term for that?
  5. Camera built-in flash

Light sources that do Not strobe/flash

  1. Natural light, a.k.a. available light, ambient light … light not supplied by the photographer.
  2. Continuous light (a.k.a. video light) … is a light source that does not strobe/flash.
    Absolutely necessary for video applications, but can also be useful for still photography.
  3. Hot light … a “continuous light” that generates much heat.
    Tungsten and HMI (a.k.a. arc light) are examples of hot light technologies.
    LED is an example of continuous light technology that is Not hot.
  4. Flashlight / Light painting … this is a bit obscure, but some photographers have used a simple hand-held flashlight to “paint” light onto a subject during a very long exposure.

Light modifiers

Umbrella (There are reflective umbrellas and shoot-through umbrellas.)
Soft box
Beauty dish
etc.