CurtPalme.com Home Theater Forum

[Jeremy112]

will the optical focus difference be on a 1272Q with HD8 lenses (bad condition ones at that) vs HD6C lenses.

I basically need the 1-100 scale because its to help a friend determine if its worth the Joust mods to make the HD6's I have unused fit his projector.

[Tom.W]

Good condition HD-8 lenses should be easy to find if you just want to replace your existing lenses.

[Ile]

I guess they are pretty same sharpness wise.

Both are decent hybrid lenses (mix of glass and plastic), HD8 is designed for 8" tubes so it's bigger.

Don't see any reason to upgrade HD8 in 1272, because ES focus tubes limit sharpness more than lenses.
HD8 is good up to 1080p in EM focus projector...

[draganm]

[Elaine Benes]

Wow, for $200. why don't you just buy a new(to your buddy) electromagnetic focus projector ??

A 9PG in decent condition just sold on ebay for $73., I wouldn't think investing $200. in Joust mods so you can squeeze a tiny bit more focus out of a lower end projector is a worthwhile endeavor...

[Jeremy112]

Well I guess the reason I ask if an upgrade to HD6 is worth it because I notice that when the lenses are off the projector while its projecting something, the image on the tubes look razor sharp compared to what it looks like on screen. I would think that the lenses have a lot to do with the transfer of the image from the tube to the screen as far as sharpness and focus.

The image looks fairly soft compared to the tubes , I know a 1272Q isnt the cadillac of projectors as far as the focus and sharpness goes, but I guess Id expect it to be a bit better than a very soft image.

I only thought about this because I've seen several posts on people with HD8s complaining about softness, and then replies to those posts about how HD8s are the cause of a large amount of that softness and that an upgrade to HD6 or HD145s...

I do have a 9PG id be willing to give him if I ever get around to fixing it... I guess I was hoping to see a bit more potential out of the 1272.

[Jeremy112]

Dragan, are there any improvements of the HD8's from 97/98 over the stock HACC HD8s on the 1272Q? Would they make a noticable difference in the image quality? If they would and you said you have a set youd give away id be interested in it then, I of course assume shipping isnt included in the price

[Elaine Benes]

Are you talking about actual HD8 lenses, or are you really talking about HD8 RevB lenses ? They are totally different lenses, and simply swapping some RevB's in will tell you if you're getting the complete potential of the projector to the screen since RevB HD8's have the same focusing capabilities as the HD144/145's, despite what some may believe, they are rated at the same lppm ability to focus.

However, PLAIN HD8's are inferior to either the RevB's or the HD144/145's, I've had a set of the PLAIN HD8's, and they are a terrible lens, very soft. If you have PLAIN HD8's, just get some free(for cost of shipping) RevB's from any number of forum members who have multiple sets cluttering up their basement/garages...

[Jeremy112]

And lastly, would replacing the capacitors on the focus board make any difference as far as electronic focus stability? I am going to be replacing several capacitors in the unit due to lack of convergence stability and I may as well make my way through the focus board if its going to help stabilize that as well

I hope not ALL my questions sound stupid

[Jeremy112]

[garyfritz]

[tse]

IIRC HD6 are good for 50% MTF with 6 line pairs /mm and the HD8 has 8 line pairs/mm with the same MTF plus the larger diameter HD8 will have less vignetting so the corners will lose less light.

Scott