We buy a nice projector that becomes obsolete before it drives itself out of the dealership... ;)
I know, it's a car analogy but it's close.

Sure the imaging chips (LCD, LCoS, DLP) get old/outdated.
The driving electronics; the same.
The power supplies get worn out or blow up (hello InFocus)
And we all know about the lamps, those hated, scorching lumps of heat buildup and despair.

But, the OPTICS?
What about the optics?

I'm a hobbyist photographer (Canon man) and good glass (L anybody?) lasts FOREVER!

And we're not talking about a lens sitting in the comfort of a home theater at 72F.
We're talking about hunks of glass being thrown about in Safaris, endure scorching sun, high humidity, dirt, dust, etc. etc. and they keep working for years to come.

Not to mention that good glass easily supports 20+ Megapixels of resolution (the new Canon full frame sensor is 21.2MP).

So, is it TOO MUCH to ask for a Projector manufacturer (for less than $50k please, maybe $5k pj) to produce projectors that I can take the lens off of my previous pj and put it on the new one?

Is it too much to ask, really?

If SLRs have been doing it with stunning results for decades, how hard would it be to STANDARDIZE lenses so that manufacturers can drop their costs???

Seriously, what's the big freaking deal?
Make it have the Canon EF mount and I can mount my 70-200 f/2.8L or my 50mm f/1.2L if I choose so. If I want to go crazy, let's put on my 400mm f/2.8L for a super long throw to show a movie outside at night...

Can you imagine when you can mount an off the shelf lens to your projector(s) for any application?

If you are not using a lens in place, put the cap on to keep the dust out.
If photographers can do it in the middle of the desert, so can we.

PLEASE, STOP obsoleting perfectly good lenses and offer standard lenses that we can all use and enjoy.

I asked a Planar engineer the very same question at a fair and his reply was that the chip, lenses and other parts has to be put together with micrometer precision at the factory. Shipping the old projector to the factory, disassemble it and assemble the lens in a new projector with high precision (and the lens might not even fit if it's not the same lens as the standard for the projector), doesn't make sense. It's cheaper just to put in a new lens and be off with the hassle.

Then of course Planar has the long and short throw lens option that you can swap, but that might just be the outer parts and a small part of the total light path? I don't know and didn't think to ask him at the occation.

Absolutely, I love this idea. I've got a good set of lenses for my Nikon D80, and if I knew my lens would outlast my projector, I'd gladly shell out the money for a lens specific for my set up. Fixed focal lenses? High end vertical/horizontal shift lenses... lenses that convert the 1080p image to a 2.35:1 throw, instead of adding more hardware on top of the current lens. Why not?

I asked a Planar engineer the very same question at a fair and his reply was that the chip, lenses and other parts has to be put together with micrometer precision at the factory.

That sounds like a cop-out doesn't it?

I mean, SLRs require at least that much precision and we take the lenses on and off hundreds and thousands of times over the SLR body's lifetime.

Sure, 1,000 lumens don't pass through an SLR lens's light path, but so what?
Other than cooking the imaging chip and the surrounding electronics, I doubt heat does anyting to damage the glass. If anything, it gives it a mild anneal (healing).

Absolutely, I love this idea. I've got a good set of lenses for my Nikon D80, and if I knew my lens would outlast my projector, I'd gladly shell out the money for a lens specific for my set up. Fixed focal lenses? High end vertical/horizontal shift lenses... lenses that convert the 1080p image to a 2.35:1 throw, instead of adding more hardware on top of the current lens. Why not?

Yeah, wouldn't fast, prime lenses be the bomb? :D

I think this is a pretty interesting idea, but they would have to make a design that wouldn't let any dust in.

I could be wrong, but I think Projection Design has this feature in the D30 and higher lines. They have about 5 lenses you can swap around.

As someone who may be getting seriously hosed in the wallet by my chosen long throw length theater design-I think it is a great idea.

I think this is a pretty interesting idea, but they would have to make a design that wouldn't let any dust in.

Don't forget that LCD projectors are still not sealed and they have been of sale for forever.

A simple inverse mount cap to seal the projector when there is not lens attached would suffice.
Also, a simple alarm that would go off if the projector didn't have the cap (or a lens on) would be helpful. A small rechargeable battery would enable the alarm to go off when the projector is off and/or unplugged.

It's doable.
Are you listening projector manufacturers?

Interesting idea, but I don't think that we're likely to see it very soon.

I think that one of the driving factors behind the interchangeability of camera lenses is that cameras are routinely used in a wide range of circumstances with differing goals. The range of circumstances for the average projector is much more limited, and for most applications will not drastically change during normal use. Any area of design standardization requires economic benefit and typically the cooperation of multiple manufacturers. In the overall scope of things the projector market itself is still a niche, and the subset of users in that market which really are driven by the need to take their projector out of their 15 foot throw room and use it with a 40 foot throw outside is smaller still.

As usual, though, the interjection of this type of flexibility will happen first at the high end of the market, and I think that we can point to examples of that now.

I know it's pushing the analogy too far, but today the lower end of the projector market is more like the fixed-focus point-and-shoot carmeras than the interchangeble lens SLR camera market.

I know it's pushing the analogy too far, but today the lower end of the projector market is more like the fixed-focus point-and-shoot carmeras than the interchangeble lens SLR camera market.

Actually, that's an excellent analogy.
Thanks for that.

But, we, hobbyists already have hundreds of millions of super high quality SLR lenses in our disposal that could be used at a moment's notice.

Tell me that you use your SLRs everyday...
I didn't think so.

A simple agreement with Canon (highest market share in SLRs >50%) and the rest of projector manufacturers will fix that.

Who's ready to use their autofocus capabilities on their projector? :D

Let's not forget that in order for SLR lenses to be interchangeable, the chips have to be at the same focal point, regardless of manufacturer. This requires that each manufacturer design to a standard. The other point is that cameras are taking an image in and focusing the light on the chip as opposed to broadcasting it out like a projector. In the latter case, the light path and design makes a HUGE difference in the projected image (I'm not saying that it is unimportant in the reverse for a camera, but the difference between the two approaches is significant). Let's also remember that three panel projectors are also using mirrors to bend the light inside the projector such that it reaches the lens at a predefined distance, which adds more complexity to the light path. Now, as we all know, different manufacturers are making significant improvements to their projected image just by changing the design of the light path and each manufacturer is doing different things with different length paths.

The net of all of this is that within one manufacturer's model, it is fairly simple to have interchangeable lenses because they are all designed to work at the focal point of the image coming through the lens for that projector's light path. Another manufacturer will have completely different specs, thus, requiring a different lens design.

Modularity? an interesting idea. But, remember this is an industry that can't even come together and agree on standard terminology. Look at the menus of just about any manufacture's projector, nobody can even figure out what to call RGB gains/offset, cuts/biases, boost/shift, drives/bias, brightness/contrast.... you get the idea. One of my favorites is setting the black level which is typically called brightness and Panasonic calls picture??? I hope I got all that right and wonder if they will be able to make it anymore confusing by coming up with more names for the same thing. At least on most $40 cell phones pressing and holding 1 will get you your messages and pressing 7 will delete them.

Modularity? an interesting idea. But, remember this is an industry that can't even come together and agree on standard terminology.Since the two biggest SLR companies, Canon and Nikon, aren't making projectors, Sony would be the most qualified to come in with Minolta/Sony's SLR experience, and could make this part of their product differentiation. They could then allow other projector manufacturers to use the same mount specs to insure compatibility, after establishing a bit of first mover advantage, and reap profits from the manufacturing of lenses. Certainly not impossible.

Most of the >30k barco projectors are modular but mostly for minimizing downtime if there is a failure. The power supply and chassis along with a few other minor parts I would think are the only items that could be used for a upgrade and combined these are not nearly 25% of the cost of the unit. Actually it is not worth upgrading nearly anything in todays world like just a few years ago.

Since the two biggest SLR companies, Canon and Nikon, aren't making projectors,

Canon makes their own projectors.
They even make their own LCoS chips.

Great idea, though, Canon should start modularizing their own projectors to enable Canon SLR users to slap on their lenses on EF mounts.

JVC introduced modular lenses on their PJ a while back (G150). It wasn't as broad in scope as you're talking about here, but even then they discontinued it with the next model.

Tom took us through hypothetical numbers and basically the price bump from going modular was too much for them to stay competitive in their target market.

You would think that if you can interchange lens on a camera, you could do the same for a projector. If anything, the camera would be more sensitive to any fluctuations of lens changing

It would somewhat depend on the camera sensor size and for that matter the projector's chip or chips size. The camera lens would have to focus all it takes in down to a tiny spot. Remember those special digital lenses for cameras with non full frame chips? Designed to sharply focus it all on a small spot. The projector lens expands it. It really doesn't matter when the chip image hits the lens going out. Hell lens shift doesn't hurt things much as ling as you stay within or near the sweet spot area. The cost of the projector would rise however. Development of a secure lens mount with appropriate electrical sockets would cost but once a lens mount was developed and put into production, I don't think it would raise costs that much. Next we will be having green projectors. Lit by LEDs using less energy than bulbs and reusable lenses. Would McCain endorse such a projector?

There are plenty of projectors that do this. They are all "professional" projectors, though, like the panasonic 7000 series, and their new HD 10K lumen model, most of Christie's offerings, and pretty much any other fixed installation type unit.

To carry your SLR analogy to it logical end, you don't see this on consumer pocket cameras. That is what you are buying when you buy a $5K HT projector.

The cheapest lenses are on the order of $1K. You are not going to move something like that in the same numbers as a $5K HT projector.

If it made business sense, they would probably already be doing it.

To carry your SLR analogy to it logical end, you don't see this on consumer pocket cameras. That is what you are buying when you buy a $5K HT projector.

The cheapest lenses are on the order of $1K. You are not going to move something like that in the same numbers as a $5K HT projector. I own a D80 (consumer DSLR) and two of my three lenses individually cost more than half the price of the camera body, and that's using the price when I bought the camera 1.5 years ago.

I'm only looking to spend $3K-3.5K on my next projector, but I'd gladly spend over $1K on the best lens that matches my setup. (within a reasonable price range, of course.) Unlike camera bodies and projectors, the glass holds it value, whether you're interested in using it with your next camera/projector or selling the glass.

I think the only reason it hasn't been done yet is that's a big risk if if doesn't work out. The benefit over some of the remarkably poor optics on some projectors would be obvious. (A recent Optoma thread about a badly bowed image comes to mind.)

They make more money if you need to buy a new device for everything you do.

Money drives the world around, its also why you want your product to be more modular, so you don't have to buy a whole new apparatus to do something with similar. Though I'd tend to jump on your boat instead of the large corporations ;)

If Canon made the first step to allow their EF lenses (even EF-S) to attach to their projector bodies, I'll bet you it would be a success.

Canon sells their projectors primarily to photographers who tend to own many lenses.

I think there is a business case here.

If Canon succeeds, more will follow and with the exception of Sony, most other manufacturers can use the same mount.

The camera lenses are pretty poorly suited to a projector. They are meant to focus on an imaging chip a centimeter or two away. Trying to design a projector and optical block so that the imagers were close enough would be non-trivial (expensive). Adding additional optics to the projector to compensate for this would add additional cost, and you then also have to make that a modular piece so IT doesn't get replaced every time too.

And then there's the issue (for brighter projectors) of whether that puts too much heat through a lens that wasn't designed for it.

The camera lenses are pretty poorly suited to a projector. They are meant to focus on an imaging chip a centimeter or two away. Trying to design a projector and optical block so that the imagers were close enough would be non-trivial (expensive). Adding additional optics to the projector to compensate for this would add additional cost, and you then also have to make that a modular piece so IT doesn't get replaced every time too.

And then there's the issue (for brighter projectors) of whether that puts too much heat through a lens that wasn't designed for it.

Good points but you can use extension tubes to move the lens further out of the sensor (to increase magnification).
So, if for instance a 25mm extension tube (or equivalent) is used, then the first issue is solved.

The second issue (about heat) I thought about it while I was starting the thread and came to the conclusion that it's not a significant.
Since the elements in the lens are constructed for minimum absorption even more so than cheap projector lenses so I don't think that's a gamestopper.

Thanks for adding to the discussion.