Handtops, UMPC - LED Projectors by Mitsubishi, Samsung an

12/21/05 + AI

I posted a reply on the post link
But I thought it be appropriate to post it with a new title.

I have been keenly searching for Mitsubishi PocketProjector for the last six months and as most of us are perhaps aware that official release has also been postponed several times. From July to September, and now 19th Dec 2005. So I called up Mitsubishi and they regretted that it is still delayed.

Mitsubishi Taiwan Asia market is reporting 1Q 2006.
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Samsung is also releasing its LED based projector called Pocket Imager (model SP-P300MK), due to be released next month (January 2006)
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The Toshiba LED powered micro projector is out in France and it is to be released in UK around Christmas (or early New Year).
Find below the hyperlinks for detail perusal:
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The images on this link are detailed however I believe the description in the article quoting 400 ANSI lumens is a mistake. Verify it with product release info from toshiba France website.
link

Those interested in checking out the projected images by Mitsubishi LED projector (model PK10 or PT10) and by Toshiba LED projector (model FF1) follow the links below:

More detail review and images with battery of Mitsubishi Pocketprojector at:
link

Click the last image in the gallery at the bottom of the page to see the projected image by Mitsubishi PK10
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The projected image by Toshiba FF1 is shown in the penultimate image on the link below. The attached battery is also visible.
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The important question is ANSI Lumen and LUX values. Samsung states 23 ANSI Lumens while Mitsubishi and Toshiba indicates 250 and 400 LUX respectively.

Using the formula described on the following hyperkink:
link

My calculations for producing a projected image of 70cm(W) by 50cm(H), approximately 83cm(33inches) diagonal view:

Mitsubishi probably has 102 ANSI Lumens (calculated) and 250 LUX(stated) compared to Samsung having 23 ANSI Lumens(stated) and 55.9LUX(calculated). Whereas Toshiba’s LED projector is rated 400 LUX (stated) and 165 ANSI Lumens(calculated). I could have miscalculated, so verify with the formula! Please note that resolution 800 X 600 is 4:3 ratio or (1.34) therefore I choose screen size 70cmX50cm, ratio (1.4).

All three projectors have SVGA (800X600)native resolution. Weight wise Mitsubishi is the lightest 450 gm (without battery) and Samsung is the heaviest 660gm(perhaps without batter). The Toshiba is 556gm (without battery)

In my assessment Toshiba LED Projector is perhaps the best of the three. I have ordered mine.

12/29/05 + zzonbi

My calculations give 5.6 lumens for Mitsubishi, 7.5 lm for Toshiba and 23 lm for Samsung (confirmed by the highest announced price).

Sorry to burst your bubble, and I hope there's a mistake in some place. It's worrying I have seen even a 300lx figure quoted for the Toshiba, further lowering its luminous flux. But it should be still usable in darkness, as I could watch even less than 1lm on a rather large screen with no gain (2m^2).

12/29/05 + zzonbi

Make that sequence 11.2, 15 and 23...

01/03/06 + AI

zzonbi,

Thanks for your response. Wondering how did you calcluate Lumen values. Is it based on the formula describe at link or did you use some other formula. Please share your calculation.

I note that you've updated your figures, by the order of 2?

I am aware of one weblink which mentions Toshiba's 300 LUX brightness but that is old and pre-release info however the official specification is 400 LUX.

01/05/06 + zzonbi

Yes, I used the formula in your link. The only presumption I made was that the lux values provided by manufacturers were for the smallest image diagonals, respectively 12 an 11 inches. Thus they look 'better' (bigger). I could be wrong, but I don't think it's very likely. Besides, looking at the lumen and price sequences it makes perfect sense.

Yes, I almost always make small calculus mitakes... In that case I derived areas thinking of phytagoreic numbers 3,4 and 5, but of course the areas are double being rectangles, not triangles.

Good to hear it's 400 and not 300. I am keen on LED projector idea too. I think these first versions will be decent though, as the eye sensitivity is logarithmic (hey, I watched even fraction of lumens projected directly from the monitor!). Same goes with hearing. I wouldn't mind having one for say half the price and double the LED life (wonder if they're easily replaceable, cause they're not expensive as spares). This technology appears to have great potential, in lumens, colours, sizes, life, consumption and prices.

Looking forward to hear how your projector fairs.

01/05/06 + zzonbi

And noise levels. I can't stand the constant pitch of spinning fans.

01/05/06 + AI

Zzonbi, in answer to your comment.

Your presumption of calculating the ANSI lumens at the smallest projection image makes great sense. Thank for your input.

Find below my recalculation based on the following parameters:

Diagonal screen 29cm or .29 meters or 11.4 inches
Screen width 24cm
Screen height 16.3 cm

Toshiba’s calculated ANSI lumens value is 18.33
Mitsubishi’s calculated ANSI lumens value is 11.47
Samsung's stated ANSI lumens value is 23, so there LUX value for the same projected image size (11.4 inches diagonally) will be 501 LUX

Which concludes that Samsung is the best of the three. I am now asking myself should I cancel Toshiba’s order and place an order for Samsung? Check out the Samsung official datasheet:
link

01/05/06 + zzonbi

Diagonal screen 29cm or .29 meters or 11.4 inches
Screen width 24cm
Screen height 16.3 cm

Toshiba’s calculated ANSI lumens value is 18.33

Let's say the screen ratio is exactly 4:3 (as in 800:600). Then the diagonal is like 5.

If the diagonal is 0.29, the area is 0.29x4/5x0.29x3/5=0.0404 m^2. Multiplied by 400 we have 16.16 lumens.

The Mitsu has a 12 inch minimal diagonal, so that helps its lumen value a bit.

Yes, the Samsung is the best at lumen output of the three (provided the presumption stands), but there are other aspects as well. It's hard to say which is the best choice for you. On paper Samsung appears favourite though. At least they were honest about, or not trying to conceal, the lumen output.

Samsung pros: brighter, vertical correction, zoom, lower noise level
Toshiba: better contrast (1500 vs 1000), sound (jacks, speaker), USB (jpg playback), miniscreen, lower consumption and price

01/06/06 + AI

zzonbi

I think you are confusing Pythagoras theorem in calculating the area of a rectangle. Let me explain:

The theorem says a2 + b2 = c2 where “a” and “b” are two arms of the triangle perpendicular to each other and “c” is the slant joining the two ends of “a” and “b”. Your example of 3,4,5 holds true because sum of squared of 3 and 4 will be equal to squared of 5, i.e. 9+16=25

However area of a rectangle is obtained by multiplying height with width, i.e. 3 x 4 = 12.
Now in my example height is 16.3 and width is 24, so their area will be 384 or 0.0384 m^2

Screen ratio for 800 x 600 resolution is 4:3 which equals to 1.33
Similarly 24:16.3 = 1.4

Using the formula you did not take into consideration the screen reflection factor, which Norbert Schmiedeberg has taken as 85% (average) in his formula. Toshiba has included its own screen for this projector which I guess will have high gain?

I hope this helps in comprehending my calculations.

Cheers,

01/06/06 + zzonbi

I think you are confusing Pythagoras theorem in calculating the area of a rectangle.

Nope, but it may be you never heard of phytagorean numbers before. 3,4,5 is the most common example. I stick to my area result.

I don't know if Toshiba used the screen gain to further 'better' their lux specifications. In my opinion a correct lumen value is independant on screen, but strictly on the light output.

Salut

01/06/06 + AI

zzonbi,

While we differ with our mathematical calculations, please find below a review of Mitsubishi Pocketprojector by Rich Malloy. His calculation estimates 11 lumens.

link
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01/06/06 + zzonbi

That's almost exactly my result. Unfortunately my presumption seems to be confirmed :/ However, the reviewer says it's OK in darkness.

As for my calculus, if you look again you will see I did in fact just that, ie multiplied the rectangle's sides, and I never missused Phytagora's theorem.

Regards

01/06/06 + garylm

The three LED projectors were all at the TI booth at CES. The Mitsubishi was slightly smaller than the Samsung. Toshiba was about half an inch thicker than the other two but was also noticeably the brightest. Mitsubishi says they'll be up to 100 lumens within 2 years.

Samsung

Toshiba

Mitsubishi

A number of companies were showing rear-projection DLPs, illuminated by LED; no color wheel needed and longer lamp life are plusses.

Recent Blog: Travelling With the OQO

01/07/06 + AI

garylm since you had the chance of evaluating LED projectors, could you please answer my queries:

1- Did Toshiba mention about its ANSI lumen values?

2- Was the projection of image in a pitch dark room or dark cubicle in the CES exhibition area? I am not expecting to display an image for an audience of 10 people, but in an office room with lights off, to give a quick snappy talk for a maximum of 5 people. For that use an image of 32" diagonal is enough. Do you agree from your experience at CES that toshiba could do the job better than Samsung?

3- Is the image to be displayed on a specially designed reflective screen for these LED projector. Did you notice any such screen at CES? A high gain screen will definitely enhance LUX values.

4- By any chance do you have any photos taken of the projected images by the three projectors.

Many thanks,

01/07/06 + AI

garylm,

It remains for me to express thanks for the photos you posted of the three LED projectors by Toshiba, Mistsubishi and Samsung.

The CES 2006 is finishing on 8th January. If you get the chance of visiting again before the closing date, could I request you to take photos of projected images by Toshiba and Samsmug LED projectors.

I desperately need this information for educational purpose to decide an order, so it would be highly appreciated.

PLEASE note that while you take photos of projected images on the screen, the flash of your camera is off, otherwise it will dim the quality of the image. You may take several images from different angles for better assessment. Cheers,

Please inquire and make observation of the following points:

2- Please note if the projection of image is in a pitch dark room or dark cubicle in the CES exhibition area?

3- Size of the projected image, is it 20" or 35" or 50 inches?

4- We know that Samsung's ANSI lumens is 23 and wish to determine the exact ANSI lumen value of Toshiba. Your observation that Toshiba is the brighest among the three is worth noting, so could you please request them the ANSI lumen value of Toshiba's LED projector, model FF1. (Not the LUX value) .

5- If Toshiba is displaying the image on a special screen then please inquire the gain value? Thanks.

Eagerly looking forward to good reponses from those fortunate ones attending the CES show and sharing information with those who are on the other side of the continent and unable to attend.

Many thanks from Scotland, UK.