chromatic aberration with Redrock Micro M2 at DVinfo.net

Ian E. Pearson · August 22nd, 2005, 11:06 PM

Unlike the mini35, the Redrock Micro M2 would mount to the Fujinon lens. I know thats not as ideal as the Mini35 but the price of a M2 makes it worth looking into. My question is would the chromatic aberration problem with the cheap lens still apply with the fujinon lens only focusing on the ground glass image?

Stefan Scherperel · August 23rd, 2005, 01:24 AM

Well, I would have to say yes, as CA is a property of the lens and has really nothing to do witht the camera, or any other optics in the camera. If the lens gives bad CA, then it will do so with a mini 35 or straight to the CCD.

Anhar Miah · August 23rd, 2005, 07:26 AM

Hmm.. Does'nt CA mostly appear when the lens is at telephoto? if so wouldn't this mean that since you probably would not need to zoom in all the way into the M2 that you may not find any CA?

I don't know much about CA so if anyone could clear this up it would be great.

Anhar Hussain Miah

Stefan Scherperel · August 23rd, 2005, 08:33 AM

WEll, let me see if I understand the question here. Ian, you want to know what would happen if you took the stock JVC lens off, added the redrcok adappter with relay lens, and then attatched the JVC lens with the mini-35? If so, you would still be usuing the lens as a normal lens, basically you would still be zooming with the lens, and allowing the relay lens to send the image to the CCD. But here is the other problem, The stock JVC lens, if I am not mistaken is meant for 1/3" CCDs. If this is true, this whole setup would not work becasue the projected image of the lens would be too small. It would not be a full framed 35mm size projection, it would be a tiny circle just large enough to covera 1/3" ccd, and show up as a cirlce in the middle of the frame.

Ian E. Pearson · August 23rd, 2005, 08:36 PM

No Stefan you misunderstood my question.

With the Redrockmicro the stock JVC/Fujinon lens IS the relay lens. You would then use 35mm cine/slr lenses. It does not come equiped to attach to camera without the stock lens (or some other lens I guess) as the relay lens. Would the CA problem with the stock lens still be apparent using it as a relay lens? I don't understand enough about light and lenses make an educated assumption. I guess it would just be in theory until someone actually tests this cam with the M2.

Barry Green · August 23rd, 2005, 09:21 PM

It is just speculation until we test it. But my guess is that yes, it would still be visible.

Michael Maier · August 24th, 2005, 07:51 AM

Stefan, what you said is not even posible with the redrock or even with the mini35. Neither to the best of my knowledge offers a 1/3" lens mount option to mount the stock JVC lens. Also, as Ian mentioned, the redrock needs to mount over the JVC lens.

Ian, what Anhar said makes sense IMO. I would guess the CA would be somewhat reduced, if not gone. But as Barry said, no way to know before testing.

Luis Reggiardo · August 25th, 2005, 10:46 PM

Just took the HD100's Fujinon lens OFF, then put a relay lens + Micro35 adaptor w/ JVC mount and then ANY 35mm lens (cinema or photo).

That way you dont use the JVC optics, hence freeing from CA...

Am I right?

L

Barry Green · August 25th, 2005, 11:19 PM

That is correct, that's how the mini35 works with the JVC HD100.

But that's pretty much only an option with the full-fledged mini35 (at $11,000). What people are asking here is, is there such a thing as a do-it-yourself relay lens so they could use an $850 Redrock Micro M2 or Micro35, instead of the mini35. And as of this time, no. The only way you could get an M2 or Micro35 on the HD100 would be to use the JVC's Fujinon lens as the "relay lens".

Thomas Smet · August 26th, 2005, 08:38 AM

What about the C mount adapter for the HD100 that I heard about at some point? I thought there was going to be one. Also what about using the 1/2" mount adapter? Since most if not all 1/2" ones are for SD would the CA actually be worse?

Anybody know how much the C mount adapter will cost?

Barry Green · August 26th, 2005, 11:08 AM

The c-mount adapter is coming, but I don't think anyone's announced a date or price yet.

Regarding 1/2" lenses: that'll be simple enough to test for. What I find interesting is the Eidomedia comparison pictures, where using a B4-mount lens, it sure looks like comparable resolution (which is surprising) while completely eliminating the aberration.

So maybe a decent-quality 1/2" lens will be "enough"?

August 22nd, 2005, 11:06 PM	#1
Ian E. Pearson Regular Crew Join Date: Jul 2005 Location: Greeley, CO Posts: 52	chromatic aberration with Redrock Micro M2 Unlike the mini35, the Redrock Micro M2 would mount to the Fujinon lens. I know thats not as ideal as the Mini35 but the price of a M2 makes it worth looking into. My question is would the chromatic aberration problem with the cheap lens still apply with the fujinon lens only focusing on the ground glass image?

August 23rd, 2005, 01:24 AM	#2
Stefan Scherperel Major Player Join Date: Dec 2003 Location: Seattle WA Posts: 209	Well, I would have to say yes, as CA is a property of the lens and has really nothing to do witht the camera, or any other optics in the camera. If the lens gives bad CA, then it will do so with a mini 35 or straight to the CCD. __________________ Stefan Scherperel SSE Productions http://www.stefweb.net

August 23rd, 2005, 08:33 AM	#4
Stefan Scherperel Major Player Join Date: Dec 2003 Location: Seattle WA Posts: 209	WEll, let me see if I understand the question here. Ian, you want to know what would happen if you took the stock JVC lens off, added the redrcok adappter with relay lens, and then attatched the JVC lens with the mini-35? If so, you would still be usuing the lens as a normal lens, basically you would still be zooming with the lens, and allowing the relay lens to send the image to the CCD. But here is the other problem, The stock JVC lens, if I am not mistaken is meant for 1/3" CCDs. If this is true, this whole setup would not work becasue the projected image of the lens would be too small. It would not be a full framed 35mm size projection, it would be a tiny circle just large enough to covera 1/3" ccd, and show up as a cirlce in the middle of the frame. __________________ Stefan Scherperel SSE Productions http://www.stefweb.net

August 25th, 2005, 10:46 PM	#8
Luis Reggiardo Regular Crew Join Date: Aug 2005 Location: Buenos Aires, Argentina Posts: 37	Just took the HD100's Fujinon lens OFF, then put a relay lens + Micro35 adaptor w/ JVC mount and then ANY 35mm lens (cinema or photo). That way you dont use the JVC optics, hence freeing from CA... Am I right? L __________________ Luis Buenos Aires, Argentina Film Student

August 23rd, 2005, 07:26 AM	#3
Anhar Miah Major Player Join Date: Dec 2003 Location: United Kindom, England Posts: 290	Hmm.. Does'nt CA mostly appear when the lens is at telephoto? if so wouldn't this mean that since you probably would not need to zoom in all the way into the M2 that you may not find any CA? I don't know much about CA so if anyone could clear this up it would be great. Anhar Hussain Miah

August 23rd, 2005, 08:36 PM	#5
Ian E. Pearson Regular Crew Join Date: Jul 2005 Location: Greeley, CO Posts: 52	No Stefan you misunderstood my question. With the Redrockmicro the stock JVC/Fujinon lens IS the relay lens. You would then use 35mm cine/slr lenses. It does not come equiped to attach to camera without the stock lens (or some other lens I guess) as the relay lens. Would the CA problem with the stock lens still be apparent using it as a relay lens? I don't understand enough about light and lenses make an educated assumption. I guess it would just be in theory until someone actually tests this cam with the M2.

August 23rd, 2005, 09:21 PM	#6
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	It is just speculation until we test it. But my guess is that yes, it would still be visible.

August 24th, 2005, 07:51 AM	#7
Michael Maier Trustee Join Date: Apr 2005 Posts: 1,269	Stefan, what you said is not even posible with the redrock or even with the mini35. Neither to the best of my knowledge offers a 1/3" lens mount option to mount the stock JVC lens. Also, as Ian mentioned, the redrock needs to mount over the JVC lens. Ian, what Anhar said makes sense IMO. I would guess the CA would be somewhat reduced, if not gone. But as Barry said, no way to know before testing.

August 25th, 2005, 11:19 PM	#9
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	That is correct, that's how the mini35 works with the JVC HD100. But that's pretty much only an option with the full-fledged mini35 (at $11,000). What people are asking here is, is there such a thing as a do-it-yourself relay lens so they could use an $850 Redrock Micro M2 or Micro35, instead of the mini35. And as of this time, no. The only way you could get an M2 or Micro35 on the HD100 would be to use the JVC's Fujinon lens as the "relay lens".

August 26th, 2005, 08:38 AM	#10
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	What about the C mount adapter for the HD100 that I heard about at some point? I thought there was going to be one. Also what about using the 1/2" mount adapter? Since most if not all 1/2" ones are for SD would the CA actually be worse? Anybody know how much the C mount adapter will cost?

August 26th, 2005, 11:08 AM	#11
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	The c-mount adapter is coming, but I don't think anyone's announced a date or price yet. Regarding 1/2" lenses: that'll be simple enough to test for. What I find interesting is the Eidomedia comparison pictures, where using a B4-mount lens, it sure looks like comparable resolution (which is surprising) while completely eliminating the aberration. So maybe a decent-quality 1/2" lens will be "enough"?