View Full Version : Canon J21ax7.8, results on PMW-350?


Gabor Heeres
April 14th, 2014, 06:16 AM
Hi All,

We have recently bought a SD broadcastlens for our PMW-400 with very good results. But it is well known not all these SD lenses perform that well on a pro HD camera. I would love the ergonomics, extra range and extender of a pro lens compared to my PMW-350K stocklens. The ideal lens for the type of work I do would be a HD 22x7.6 but I just can't afford it now.

On various places on the internet I find this Canon SD lens at attractive prices: J21ax7.8B4 IRS SX12. These lenses are up to 10 years old though I read people have had great results with it using a PMW-EX3 and adapter. But how will it perform on the PMW-350 without an adapter? Anyone has (heard) experiences? There is not one for sale or to test nearby so it will be a guess-buy over the internet anyway. All resumed only one question:

Autofocus is not an issue, is the Canon J21ax7.8B4 IRS SX12 better or worse than the PMW-350K stocklens?

Gabor Heeres
April 17th, 2014, 04:53 AM
148 topic-reads and no replies. I just took the guess and bought one for only a little less than € 1.5K. I must admit, it's not stunnig sharp but still very usable, even with extender. Though focus is to be used very carefully. As you see in the clip linked below, it's immediately highly visible if only slightly out of focus. Not superb, but for the money not that bad at all.

Canon j21ax7.8 SD lens on PMW-350 HD camcorder test - YouTube

Paul Anderegg
May 19th, 2016, 11:42 PM
I used a matched set of J22x7.6 and J11x4.5 Canon lenses on my HPX2000. They worked a bit better than that J21 you tested. I worked mainly night ENG, but can say those newer lenses had a bit less chromatic aberration and fuzz.

For HD work, I found that it is EXTREMELY important to have a smooth focus ring on your old SD glass. As you found, you really need to be able to tip in and out to find that perfect focus, and if your used lens has a tight focus mechanism, you'll end up overshooting back and forth as the ring jerks past the spot you want. I would say ASK any seller before purchase about that, as it is a very big deal......gotta be "like silk".

Paul

Paul Anderegg
October 1st, 2017, 09:58 PM
I was watching a National Geographic show from 2007, and it was obvious it was shot with a first gen Canon HJ21...you could see blue ringing/edges and the same green/magenta chroma issue when not in focus. I think this os one of the big advancements made in the newer series lenses, as they were trying to get higher MTF resolution out of the fist HD glass, but not making great strides into image artifacts. Where you are probably seeing the most issue would be when engaging the 2x, very blurry. A 2x on a modern new HD lens is about as clean and sharp as without. The Fujinon HA18x7.6BERM with CAC is a great value lately, $3000-4000 and most cameras will recognize it for auto CA reduction.

Paul