Optoma ML750ST LED/DLP Video Projector - Review

Optoma ML750ST LED/DLP Video Projector - Front/Rear Views With Remote
Optoma ML750ST LED/DLP Video Projector - Front/Rear Views With Remote. Photo © Robert Silva - Licensed to About.com

While TVs have been getting bigger and bigger - The opposite is happening with video projectors. Technology innovation has resulted in a whole breed of video projectors that are very compact, yet can still project very large images - and a price lower than many of those large screen TVs.

One example is the Optoma ML750ST. ML750ST stands for the following: M=Mobile, L=LED light source, 750=Optoma Number Designation, ST=Short Throw Lens (explained below)

This projector combines lampless DLP Pico chip and LED light source technologies to produce an image that is bright enough to be projected on a large surface or screen, but is very compact (can fit in one hand), making it portable and easy to set up not only at home, but in a classroom or business travel (it comes with a compact carry bag).

To find out if the Optoma ML750ST is the right video projector solution for you, keep on reading this review.

Features And Specifications

1. The Optoma ML750ST is a DLP Video Projector (Pico Design), utilizing a Lamp-Free LED light source, with 700 lumens of white light output and 1280x800 (approximately 720p) display resolution. The ML750ST is also capable of projecting 2D and 3D images (optional glasses purchase required).

2. Short Throw Lens: 0.8:1. What this means it that the projector is capable of projecting large images from a very short distance. For example, the ML750ST can project a 100-inch size image from about  5 feet from a screen.

3. Image size range: 25 to 200-inches.

4. Manual Focus via ring surround lens exterior (No mechanical Zoom control). A Digital Zoom is provided via the oncscreen menu - However, image quality is negatively affected as the image gets larger.

5. Native 16x10 Screen Aspect Ratio. The ML750ST can accommodate 16x9 or 4x3 aspect ratio sources. 2.35:1 sources will be letterboxed within a 16x9 frame.

7. Automatic video input Detection - Manual video input selection also available via remote control or buttons on projector.

8. Compatible with input resolutions up to 1080p (including both 1080p/24 and 1080p/60). NTSC/PAL Compatible. All sources scaled to 720p for screen display.

9. Preset Picture Modes: Bright, PC, Cinema, Photo, Eco.

10. The ML750ST is 3D compatible (active shutter) - Glasses sold separately.

11. Video Inputs: One HDMI (MHL-enabled - which allows physical connection of many smartphones, as well as other selected devices), One Universal I/O (in/out) port for VGA/PC monitor purposes, and one audio out (3.5mm audio/headphone output).

12. One USB Port for connection of USB flash drive or other compatible USB device for playback of compatible still image, video, audio, and document files. You can also use the USB port to connect the ML750ST Wireless USB dongle.

13. The ML750ST also has 1.5GB of memory built-in, which an addition MicroSD card slot that will accept a card with up to 64GB of memory. This means that you can transfer and save photos, documents, and video in the projector (as space allows) and play or display them back at any time.

14. Fan Noise: 22db

15. In addition to traditional video projection capabilities, the ML750ST is also has Optoma's HDCast Pro system built-in, but still requires connection of an optional Wireless USB dongle and installation of a free downlodable mobile app for use.

However, employing the optional plug-in wireless dongle and app, HDCast Pro enables the projector to wirelessly access content (including music, video, images, and documents) from compatible Miracast, DLNA, and Airplay compatible devices (such as many smartphones, tablets, and laptop PCs).

16. Built-in Speaker (1.5 watts).

17. Kensington®-style lock provision, padlock and security cable hole provided.

18. Dimensions: 4.1 inches Wide x 1.5 inches High x 4.2 inches Deep - Weight: 12.8 ounces - AC Power: 100-240V, 50/60Hz

19. Accessories included: Soft carry bag, Universal I/O cable for VGA (PC), Quick Start Guide, and User Manual (CD-Rom), Detachable Power Cord, Credit Card Sized Remote Control (with batteries).

Setting Up The Optoma ML750ST

Setting up the Optoma ML750ST is not complicated, but can be a little tricky if you haven't had previous experience with a video projector. The following tips provide a guide to get you going.

To start, just with any video projector, first determine the surface you will be projecting onto (either wall or screen), then position the the projector on a table, rack, sturdy tripod (a tripod mounting hole is provided on the bottom of the projector), or mount on the ceiling, at the optimal distance from the screen or wall. One thing to keep in mind is that the optoma ML750ST only requires about 4-1/2 feet of projector-to-screen/wall distance to project an 80-inch image, which is great for smaller rooms.

Once you have determined where you want to place the projector, plug in your source (such as a DVD, Blu-ray Disc player, PC, etc...) to the designated input(s) provided on the rear panel of the projector. Then, plug in the power cord of the Optoma ML750ST and turn on the power using the button on the top of the projector or the remote. It takes about 10 seconds or so until you see the Optoma logo projected on your screen, at which time you are set to go.

To adjust the image size and focus on your screen, turn on one of your sources.

With the image on the screen, raise or lower the front of the projector using the adjustable foot (or adjust the tripod angle).

You can also adjust the image angle on the projection screen, or white wall, using either the automatic Keystone Correction feature, which senses the degree of physical projector tilt). If desired, you can also disable Auto Keystone and perform this task manually.

However, be cautious when depending on auto or using manual Keystone correction, as it works by compensating the projector angle with the screen geometry and sometimes the edges of the image will not be straight, causing some image shape distortion.

The Optoma ML750ST Keystone correction function only works in the vertical plane (+ or - 40 degrees)

. You may find that in addition to using Keystone Correction, it may be necessary to place the projector on a table, stand, or tripod that results in a the projector being more level with the center of the screen in order to make sure that the left and right sides of the projected image are vertically straight.

Once the image frame is as close to an even rectangle as possible, move the projector to get the image to fill the screen properly, followed by using the manual focus control to sharpen your image.

NOTE: The Optoma ML750ST does not have a mechanical/optical Zoom function.

Two additional setup notes: The Optoma ML750ST will search for the input of the source that is active. You can also access the source inputs manually via the controls on the projector, or via the wireless remote control.

If you have purchased accessory 3D glasses - all you have to do is put on the glasses, turn them on (make sure you have charged them first). Turn on your 3D source, access your content (such as Compact Blu-ray Disc), and Optoma ML750ST will auto detect and display the content on your screen.

Video Performance

In my time with the Optoma ML750ST, I found that it displays 2D high-def images well in a traditional darkened home theater room setup, providing consistent color and detail, and flesh tones appear accurate. Contrast range is very good, but black levels are not inky black. Also, since the displayed resolution is 720p (regardless of the input source) the detail is not as precise as it would be from a projector with 1080p display resolution.

With its maximum 700 lumen light output (bright for a pico projector, but I have seen brighter), the Optoma ML750ST can project a viewable image in a room that may have some very low ambient light present. However, for best results, use the ML750ST in a darkened room as black level and contrast performance is sacrificed (the image will look washed out) if too much ambient light is present.

The Optoma ML750ST provides several pre-set modes various content sources, as well as two user modes that can also be preset, once adjusted. For Home Theater viewing (Blu-ray, DVD) the Cinema mode provides the best option. On the other hand, I found that for TV and streaming content, the Bright mode was preferable. For those that are energy conscious, the ECO mode is available, but the images are very dim - my suggestion is to avoid it as a viable viewing option - even in Bright mode, the ML750ST only consumes an average of 77 Watts.

The Optoma ML750ST also provides independently adjustable brightness, contrast, and color temperature settings, if you prefer.

480p, 720p, and 1080p input signals are displayed well - smooth edges and motion - but with 480i and 1080i sources, the edge and motion artifacts are sometimes visible. This due to some inconsistency in performing interlaced to progressive scan conversion. It is important to note that although the ML750ST will accept 1080i and 1080p resolution input signals, those signals are downscaled to 720p for projection onto the screen.

This means that Blu-ray Disc and other 1080p content sources will look softer than they would on a projector or a TV that has 1080p native display resolution.

Also, when evaluating projector performance, it also important to note the fan noise level, as a fan that is too loud can be distracting to viewers, especially if sitting in close proximity to the project.

Fortunately, for the ML750ST, the fan noise level is extremely low, even sitting as close as 3 feet from the projector. In summing up the ML750ST's video performance, given its extremely small size, limited lumens output, and 720p display resolution, it performs better than I would have expected.

NOTE: 3D performance not tested.

Audio Performance

The Optoma ML750ST incorporates a 1.5 watt built-in amplifier and speaker. Due to the size of the speaker (obviously limited by the size of the projector), the sound quality is more reminiscent of a cheap portable AM/FM radio (in fact, some smartphones sound better) than something that enhances the movie viewing experience. I definitely recommend that you send your audio sources to a home theater receiver or amplifier for that full surround sound listening experience, connect the audio outputs of your source devices to a stereo or home theater receiver, or if in a classroom situation, an external audio system for best results.

What I Liked About The Optoma ML750ST

1. Very good color image quality.

2. Accepts input resolutions up to 1080p (including 1080p/24). NOTE: All input signals are scaled to 720p for display.

3. High lumen output for a Pico-class projector. This makes this projector usable for both living room and business/educational room environments - However, the light output is still not enough to overcome ambient light issues, so a windowless room, or a room that can light controlled is desired for best results.

4. Compatible with 2D and 3D sources.

5. Minimal DLP Rainbow Effect issues (there is no color wheel, which is common in most DLP video projectors).

6. Very compact - easy to travel with.

7. Fast turn-on and cool-down time.

8. Headphone Output (3.5mm)

9. A soft carrying bag is provided that can hold the projector and provided accessories.

What I Didn't Like About the Optoma ML750ST

1. Black level performance is just average.

2. Images appear soft on screen sizes 80-inches or larger.

3. Under-powered built-in speaker system.

4. There is only one HDMI input - if you have multiple HDMI sources, my suggestion would be to either use an external or if you have an HDMI-equipped home theater receiver in the mix, connect your HDMI sources to the receiver and then connect the HDMI output of the receiver to the projector.

5. No dedicated analog audio input (audio in from HDMI and USB only), No composite or component video inputs.

7. Remote control not backlit - but does feature black lettering on a white background.

Final Take

Optoma definitely has an interesting take on video projection with the ML750ST. On the one hand, it utilizes a LED light source, which means no periodic lamp replacement issues, projects a bright image for its size (although you still need a darkened room for best results), and it is extremely portable. Also, via an added USB Wifi dongle - there are added content access capabilities.

However, the fact that the projector has a native 720p display resolution, the 1080p source material does look soft - especially when you get into the 80-inch, and above, image size range, and getting the Keystone correction settings right so that you get a perfect rectangular image borders is a little tricky.

Also, it would have been nice to have included more than one HDMI input, as well as composite and component video inputs for older video source components, but with limited rear panel space, compromises did have to be made.

If you are looking for a dedicated home theater projector, the Optoma ML750ST is not the best choice. However, if you desire a projector for more general use that provides acceptable large screen viewing experience (especially good for small spaces), physical and wireless (with adapter) content access, and is also very portable, the Optoma ML750ST is definitely worth checking out.

Disclosure: Review samples were provided by the manufacturer unless otherwise indicated. 

Additional Components Used In This Review

Blu-ray Disc Players: OPPO BDP-103 and BDP-103D.

DVD Player: OPPO DV-980H.

Projection Screens: SMX Cine-Weave 100² screen and Epson Accolade Duet ELPSC80 Portable Screen - Buy From Amazon.