Film-Tech Forum ARCHIVE: What exactly is an SD lamp?

This is topic What exactly is an SD lamp? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=000461

Posted by Brendan Penny (Member # 5041) on 11-09-2009, 11:38 PM:

Was wondering if someone could clarify this.

The Christie ZX spec says it takes standard 30CXL lamps but also an ultra bright 30CXL SD lamp which is supposedly much brighter due to a shorter arc etc etc .

From what I can gather, the ZX can only meet DCI illumination requirements on say an 18m screen when using an 'SD lamp'. A normal 3k lamp won't hit the mark.

What exactly is the deal here because those SD lamps are crazy for both price and warranted hours.

Posted by Steve Guttag (Member # 268) on 11-10-2009, 05:42 AM:

Actually, Christie only specifies the CDXL lamps for the ZX...that is, the CDXL-20, CDXL-30 and CDXL-30SD. Though with suitable adapters, one can use the CXL line. Note, through my own testing, you are not going to get the light nor life from a CXL (cinema) that you would on a CDXL (Digital cinema).

The CDXL-30SD is a very special lamp. It gets just shy of a 4K lamp in lumens but at the power of a 3KW (plus it has more headroom power wise). It is physically shorter than a normal Christie 3K.

If you are more interested in the lamp particulars, I suggest downloading the xenon lamp brochure from the Christie Digital site. It will show you what it physically looks like.

Steve

Posted by Mark Gulbrandsen (Member # 72) on 11-10-2009, 12:22 PM:

Then other thing about the SD lamps is that they are designed to be run at full power from the first strike while maintaining that specified light output over the rated life of the lamp. The CDXL short gaps should be started out lower in current and increased sometimes though the projector's light loc software to maintain a certain required light level.

Mark

Posted by Brendan Penny (Member # 5041) on 11-10-2009, 03:45 PM:

Ahh o.k that makes sense. I was wondering how they got up to around 17k lumens with a 3k lamp.

The only issue I see is due to the fact they are so expensive and warranted for low hours it works out to be around $2.30 an hour to run! (I don't know about you guys but we pull the lamp right on warranty as we don't want a reflector bill.)

So having said that, if one required more light would it be best to go for an SB so you could use a less expensive 4k CDXL? When you think about it you are paying an extra 1k for every lamp every 700 hours. That seems a bit excessive.

Do any of your customers get a shock when they start getting massive lamp bills after converting to D-cinema? Are there cinemas out there that push the hours beyond warranty?

Posted by Chris Slycord (Member # 4239) on 11-10-2009, 03:58 PM:

Of course there are cinemas that go past warranty. A lot of places will do the simple "replace it when it starts to flicker."

Posted by Steve Guttag (Member # 268) on 11-10-2009, 07:19 PM:

The CDXL-30SD is a CP2000-ZX exclusive. So if you have a ZX...then that is the BIGGEST lamp you can put in it.

CDXL-45 (there is no 40) is MORE expensive than the CDXL-30SD (in fact it is less than $100 cheaper than the CDXL-60). Furthermore, you would need the CP2000-SB to use it (both physically and power wise). It is an incredible lamp though...it is about 38% brighter than a CXL-40. Its burn back is MUCH slower...you will loose about 20% of your light on a CXL lamp within 100-hours. The CDXL-45 will only loose about 10% of its light after 300 hours.

Its only down side is it is an expensive lamp.

Steve

Posted by Darryl Spicer (Member # 711) on 11-10-2009, 09:36 PM:

quote: Chris Slycord
Of course there are cinemas that go past warranty. A lot of places will do the simple "replace it when it starts to flicker."

I wouldn't do that with a lamp used in a digital projector. It is not cheap to replace the reflector in a digital projector if a bulb blows out of warrenty. I don't like to do it in consoles used for 35mm.

Posted by Brendan Penny (Member # 5041) on 11-10-2009, 10:44 PM:

Of course your prices for lamps are probably better than what we get in Australia.

Here's something that gets me thinking.

To get around 18000 lumens I need a ZX with a Christie 'SD' lamp. Cost of the lamp here is around $2400+tax warranty = 700hrs

Or one could buy a Barco DP2000 with a 4k lamp to get 18000 lumen for the cost of $1100+tax warranted to 1000hrs

If you took each out at warranty the cost per hr for the user is:
Christie: $3.42 per hr
Barco: $1.10 per hr
Nec: ??

So for a 10 plex running ZX's for one year 14hrs per day. Cost for exhibitor would be around $174,762.00

Cost to run 10 Barco's will be around $56,210.00

This can't be right can it??

(Obviously I'm working in Aussie dollars!!)

Posted by Mark Gulbrandsen (Member # 72) on 11-10-2009, 11:15 PM:

The Christie SB Reflector is in excess of 7 grand, Heat filter assy is about 1200 more, the dolby wheel is another 14 grand above that! Should the flying glass from the exploding Dolby wheel scratch the integrator rod add about 2000 more. As you can see you don't wait for the lamp to start flickering!!!

Mark

Posted by Steve Guttag (Member # 268) on 11-11-2009, 06:31 AM:

I can't speak to your prices as you clearly have other factors in play there. It is true that using a the DXL-40AF is a cheaper lamp to run than the CDXL-30SB, from a lamp cost wise...also, you need to factor in your electric costs as you will be using about 33% more to light up the 4KW lamp.

However, your Aussie dollar should be doing very well to our US dollars right now...almost parity! Come to the States and go on a shopping spree.

Steve

Posted by Chris Slycord (Member # 4239) on 11-11-2009, 09:34 AM:

quote: Darryl Spicer
I wouldn't do that with a lamp used in a digital projector. It is not cheap to replace the reflector in a digital projector if a bulb blows out of warrenty. I don't like to do it in consoles used for 35mm.

Not saying it was recommended. He was asking IF some people do it... and definitely some people do.

Posted by Brad Miller (Member # 2) on 11-11-2009, 10:56 AM:

This is an excellent reason why junk lamps should not be used in digital equipment. Cutting corners on a lamp is the stupidest thing you can do for D-cinema.

Posted by Pete Naples (Member # 761) on 11-11-2009, 11:42 AM:

AFAIK SD lamps are not available in the UK for some reason. I've had a few places enquiring about them.

I have one place where I'm fighting to get them to replace the lamp (it has run past the rated hours) Yet they complain about the light output!

Oh and trying to persuade owners to put forced extract on them! Then they complain about lamp life.

So they'll happily spend £60,000 or thereabouts on a DLP but won't spend £200 on a fan and a length of ducting.

Madness, utter madness. [Roll Eyes]

Or sites who won't spend a predetermined amount every year on contracted maintenance, would rather spend twice that on ad hoc call outs, and expect you to attend yesterday, if not sooner. [fu]

Posted by Sam D. Chavez (Member # 1841) on 11-11-2009, 01:10 PM:

Pete.

Welcome to our world Dorthy, although you've been at this for a while.

Logic is not the answer with cinema operators.

Posted by Monte L Fullmer (Member # 2797) on 11-11-2009, 01:37 PM:

quote: Brad Miller
This is an excellent reason why junk lamps should not be used in digital equipment.

Why I get a bit nervous running default Philips/LTI bulbs in our NEC 1600 units (already had one go blue on me after 50 hours of operation..) ..

-Monte

Posted by Chris Slycord (Member # 4239) on 11-11-2009, 01:43 PM:

People should feel nervous running LTI's ever... not just if it's digital.

Posted by Mike Moreno (Member # 4887) on 11-14-2009, 06:50 PM:

we use CDXL-60 for a CP2000-SB didsomebody know theexactly ours that christie recomend for normal use?

and the warranty.

mike moreno

Posted by Mark Gulbrandsen (Member # 72) on 11-16-2009, 09:11 AM:

600 hours last I checked. A customer had one explode and do about 20K in damage to an SB at 640 hours. Odd they claim 1000 hours average life on their web site.. that sure is mis-leading and risky! Another location that also uses them (Zion Canyon) runs them to about 1K hours even though an explosion will cost them a reflector and heat filter.

Mark

Posted by Brad Miller (Member # 2) on 11-16-2009, 12:09 PM:

The light difference between the CXL-60 and CDXL-60 is very minimal. I wouldn't bother unless you have a REALLY big screen that is choking for light.

The lower wattage CDXL bulbs do quite nicely though.

Posted by Monte L Fullmer (Member # 2797) on 11-16-2009, 01:15 PM:

I used to run CXL-60's in a SLC-45 "Reference" console (which I found out that Christie no longer makes..) and run them well over 1500hrs without any problems. Course, the "45" had tonnage of air blowing on the seals and we had major exhaust flow.

Posted by Steve Guttag (Member # 268) on 11-16-2009, 09:21 PM:

While it is true that the CDXL-60 only gains about 10 or 11% over the CXL-60...when new. If you check the light levels 100-hours in, the margin will grow greatly. The CDXLs have a very slow burn-back as compared to CXLs.

Steve

Posted by Brendan Penny (Member # 5041) on 11-16-2009, 10:04 PM:

O.k now for the million dollar question! The components to make a CDXL I assume are identical to a CXL. Same amount of tungsten, maybe a little more gas, different physical size.

So why are they double the cost?

Posted by Steve Guttag (Member # 268) on 11-17-2009, 05:20 AM:

Actually, the quantity of the materials are not the same, nor their shape.

I'm sure part of their cost has to do with the R&D combined with "relatively" low volume as compared to other lamps. It would not surprise me to see their cost drop over time just as conventional xenon lamps have come down, relatively.

Posted by Mark Gulbrandsen (Member # 72) on 11-17-2009, 09:21 AM:

The anode is at least twice as large in an SD lamp and there is more gas inside also meaning that it runs at higher pressures...

MArk