Analog Projectors - A few questions

Hi,

I was thinking of getting this analog projector from Goldenstar and had a few questions. H-RGB700 - $520.00 : Laser Light-goldenstarlaser.com, Laser Light-goldenstarlaser.com
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1)Are all Analogs 16.7million Color?

Are there Analog Projectors available that do not have 16.7 million colors if they do not have the log response feature or do all Analog projectors have the full color palette regardless? In the Quick Show tutorial on settings the 16.7 million colors is only available after selecting the analog with "log response." Is there such thing as an analog projector that does not have log response?



2)How easy is it to ruin galvo scanners and what is there average lifetime?

DT 30 Scanners is probably what I will want but for a noob like me will it be easy to accidentally over extend the scan range beyond the maximum 60 degrees when I first turn on QS and begin to try it out? Are there any failsafe measures to prevent this or does QS have the ILDA test pattern already set at a safe amount of degres as a default? Would this be for example just leaving it at 50% and not moving the position of the projection space away from the center position? I am actually quite poor (despite being into an expensive hobby) so I am worried that I would probably be eating dog and cat food afterwords if I had to replace the scanners.



3)Are there Analog projectors with lower power outputs than 700mW?

15 feet to maybe 18 feet max is about as a far from a wall inside my house as I can have the projector so will it be too bright for the small space? It seems there are lots of lower powered TTL projectors but it is hard to find an Analog one that is lower powered. (This is the least powerful analog Goldenstar has.) I would like to purchase something prebuilt since I don't have the skill to build my own at the moment. Any thoughts on other availiable lower powered Analogs or if this brightness in a small space would be tolerable? I am wanting to be able to do beam shows as well as graphics with the help of fog.

Thanks very, very much to anyone who can help me! :thanks:

:gh:

1. The 16.7 is a theoretical number based on a 8-bit RGB DAC. (2^8)^3 ≈ 16.7 million. There are some DACs that have more or less than 8-bit color outputs. It is also assumed that output is directly proportional to input level which isn't the case. The level is much higher than you'd expect before the laser even turns on. I've got a 473 that doesn't lase until a value of ≈75 (out of 255), and a green that doesn't lase until a value of ≈130. So in general you can expect fewer than 16.7 million colors.

2. Galvos don't pop from abuse too often. Try your best to keep within tolerances, and shut it down if they start screaming or making other unusual noises. You should be fine.

3. Powers can go as low as you want. However, 1W is not too bright for household use.

Thanks for your help Cyparagon.

Sounds like I should be ok with something around 1W or less than. I was trying to compare the brightness by thinking of the relative power of handhelds that I have seen. When I think of 1W in a handheld indoors it seems pretty overkill although I guess that isn't quite as accurate of a comparison with a projector because the mW power is spread out over a larger area in the projected image or abstract etc, and you are technically not staring at the laser dot for any length of time as it is constantly moving with the projector's scanner mirrors. Unless I guess you were just projecting stationary "hot beams" in which case you wouldn't want to stare at the dot at close range for any period of time...

Just out of curiosity Cyparagon, do you or does anyone know of a a premade really low powered analog maybe around 300mW total? Something around 100mW 445, 120mW 635nm, 80mW 532nm approximately if this exists.

:beer: :thanks:

Cyparagon said:

However, 1W is not too bright for household use.

Click to expand...

That's funny, I built my first white light projector about 16 or 17 years ago. HeNe for red and a 60X argon for green/blue. Total balanced output after the galvo's was around 35-40mW. That was bad to the bone back then! In fact, I used that projector up until about 2001 when I first started running laser shows in my garage for halloween. This is a very old video as you can tell by the quality, but the graphics there are 35-40mW. A friend brought over a 250mW Reliant argon running the beams. halloween laser show - YouTube

It's been amazing to see the changes to this industry over the years. I've gone from gas to solid state back to gas. Anyway, even if you could get 16.7 million colors, you'd never really know. At 15-18 feet you should be able to just about fill a wall, but not with the ilda test pattern. This test pattern is very taxing on scanners. You basically want to display the ilda test pattern at a very low setting and slowly increase the size until the circle begins to fall apart, then back it off a bit. This is where you would tune the scanners if you needed to. For displaying regular show content you can crank the size up about double. The DT scanners have a fuse and poly switch, though I find them to be rather ineffective. It's not an exact science, you just have to watch what's being displayed, if a corner starts to collapse or an image begins to distort, you need to back off the scan angle a bit or reduce the speed. Sometimes, for beam shows, I'll back the speed down to 20-22k and ramp up the scan angle to max.

Good point. Almost all hobby projectors were less than 1W up until a couple years ago. We had to use 473nm, and that was NOT cheap.

You can modify the drivers of an existing projector to operate at lower power. A reverse "pot mod" if you will. Or you can simply change the settings in software.

Thanks again Cyparagon and thanks DJZ for your very helpful suggestions! I actually don't have quickshow yet, but I have seen the tutorials using some of the ILDA test patterns. I'm not sure if I have seen the one that you mentioned referring to the size of the circle and looking out for it to distort with too large a scan angle.

The tutorial showed the square shaped grid of horizontal and vertical lines and the arrangement of circles that form a larger single circle. Are these appropriate as well for testing the boundary of the maximum scan angle in terms of complexity?

Cyparagon said:

Good point. Almost all hobby projectors were less than 1W up until a couple years ago. We had to use 473nm, and that was NOT cheap.

You can modify the drivers of an existing projector to operate at lower power. A reverse "pot mod" if you will. Or you can simply change the settings in software.

Click to expand...

Blue used to be the limiting factor indeed. Nowadays there are very powerful 640 and 445 nm diodes readily available and green is the limiting factor since that is mostly still DPSS.

On this particular unit i guess the blue output is too high compared to the red and green installed, and you may want to tune that down a bit if you require proper color balance.

Having never owned or experienced an analog- PJ you may be quite happy with a TTL 500mW like the Reke500rgb- if , later you upgrade you will always have many good uses for the TTL- being light weight and low cost its perfect for making new shows- This can be done without a PJ conected to your PC and QS but I have been told by the pros that seeing it on the wall is much better than just in QS. also having a Chijector saves hours on an expensive one. Sales and promo codes come and go- you will want to order when the time is right.- With Xmas coming you may be wise to wait a while. the right combo of codes/discounts and feree shipping could mean a big savings. ATM Yourlaser offers free shipping onthe reke500 at $308 before promo code. Expect it to meter around 600mW with front window in place- you can gain around 60 more mW with it removed- The green modules they use are underspec- the reds(two cubed) are a little overspec and the Blue is way overspec. the white produced is decent for what you are paying. Most arrive needing some tweaking that is not too difficult contact me or any other ROG member to find out how.


hak

Hi Hak,

Thank you very much for the helpful suggestions! :beer:

After some thought that is actually what I am thinking too about going with a TTL first instead of an analog. For the price of the REKE or a similar TTL I could probably get it and QS from you cheaper than the Analog projector (before shipping even.)

I am totally new to projectors so I know I will be more than amazed with a TTL even having the smaller color palette. If I got the Analog first I probably wouldn't be able to afford the software anytime soon afterwards, and after seeing the tutorials on QS I can't imagine not being able to control the PJ through the software in realtime and with the possibility to add personal creativity in programming a timeline of effects and animations in the shows in sync to music and also creating new graphics and effects etc. from scratch. It just sounds great!

Thanks, also that is excellent advice on waiting for some Christmas specials, if I can hold off from my urge to buy one for too long. :san:

Most of these cheap China units will always be blue heavy, now that it's so cheap. They can boast about the extra power, when really they're only increasing the red and green say 50mW from their lower model, and the blue an extra 300mW.

Most good lasershow softwares allow you to set a max value for each colour, so you can tune them down there without voiding your warranty.

Although you can _theoretically_ get 16mil colours, the linearity of the lasers + the human eye means you're not going to notice differences even in the hundreds of colours, let alone millions.

Thanks Things!

That is a good point to keep in mind to look for the jump in 445nm output /price for lesser increase of other wavelengths.

If your PJ is TTL, can you still adjust the relative powers or brightness such as in the example of adjusting for an excessively 445nm heavy RGB that is tinting the white blue? If TTL is either 0V or 5V (on or off) would this make it impossible to do any adjustment in the relative output through the software?

Yes, the only way to adjust the TTL laser would be to "reverse pot mod" it, you have no control of power apart from that.

From my experience no two Reke 500rgbs(ttl) make the same 'white' and we do not all see white the same anyway.

PM Cherrylee here at LPF and keep asking here abpout a sale price and a better promo code for YL-
keep watching the tutorials located free at Pangolin- all that pre-studying will make your learning curve much easier when you have both a PJ and QS- all the cues and frames in QS are automatically hooked to keys on your PC keyboard so you can change cues with a touch or your fingers- you choose to transition or not- you have choice of one cue at a time or two or three-- playing abstracts on the fly to your fav music is easy and with practice anyone can do some neat live lasering to music.
Same for beamshows-- with cones/waves/sheets and hot beams.

cheap window sheers from thrift shops make swell skrims- shoot thru more than one for nice and easy 3-D effects.

like these...