Letus focal ranges of lenses (FD) on canon HV20
Alright, so I finally got tired of missing the mark on focusing, and not being sure when I could use certain lenses with my Letus Mini/HV20.
I don't know if it is only MY Letus but here is what I found. I think it will be very useful to Letus/ Letus mini owners:
1. I don't know if I can adjust the back focus to calibrate my Letus better, BUT I have tried and not had any luck. If anybody has a sure fire method please let me know!!
2. My super wider, Sakar/ semi fish lens is VERY cool. I love it!! But forget about achieving infinity focus, and for that matter, none of my lenses will achieve infinity focus with the Letus. But the range that I can get tack sharp focus with the Sakar / semi fish is between 1 and a half inches of the subject to 2' 9 "..... Thats all. any closer or further from the target and forget about tack sharp focus. Trying to cheat by using the camera's focus ring to further dial in focus yields bad results. Don't bother.
3. My 50 mm. canon lens will be tack sharp between 2 feet and 5 feet. Any closer or further yields NO PERFECT focus.
4. My 28 mm. canon lens is tack sharp between 7 inches to 2 feet 9 inches of the target. THATS IT!!.
4. If anyone finds this irregular or hard to believe, please test out your lenses very carefully before reacting. IF you find that you get better results, PLEASE detail how you achieved it for me.
*** By the way, all of the lenses were set to 5.6, which is the sweet spot/ sharpest spot.
Also, You might want to really test this yourself. I've had the Letus for a long time, and didn't realize how finicky the focal ranges were. Its easy to dismiss this information, and hopefully you CAN.
But if my measurements are typical of the Letus/ Canon kit, then you can use these measurements to ensure you don't use the wrong lenses for the wrong shots because a lot of the time it will look sharp on the LCD, but in the editor you'll notice that it could have been even just a little bit sharper. That is why I think that so many Letus clips seem muddy. They arent tack sharp, or set up right, and the camera operator used the wrong lens, not understanding how tricky the Letus/HV20 kit is.
I hope this helps, and at least inspires some experimentation.
It SURELY helped me, and I'm certain that my Letus footage will be much better now.
and by the way
You should send the unit back to letus for adjustment. You should be able to focus your lenses to infinity if you're using the correct mount. The backfocus is probably incorrect on your unit.
They have terrible customer service. I would be too afraid to send it to them. It may take forever to get back, if at all. I tried to adjust the back focus, but it didn't seem to really improve anything no matter what I did. I have it set at the best " I " could get it.
I have to mention though, that I'm not taking it lightly, or throwing this info out there because I think I have a unit that is not calibrated. What I think, by looking at all HV20 letus footage, is that there is an inherent flaw in the design that makes infinity focus not possible. I'd like to be proven wrong. I know on the EX1 the focus is much better, but for the HV20, I haven't seen anybody get sharp infinity focus EVER.
This makes using a 50 mm. lens (for me) very confined, at such a short range.
With my 70 - 210 mm. zoom lens I have a much longer range. Probably up to about 100 ft. ( I think ). I have to do the same kind of testing for the zoom at closest and furthest ends for where it is sharp, and Not.
I think if it is possible for me to fix the back focus, then I'll be able to do it without sending it back to Letus. If its possible, which I'm guessing its not, then somebody will know the best way. But I don't think I'm alone in my conclusions. Anybody who has a Letus should really test your lenses for optimum focus possibilities before replying to this. As I said, It might look close to being sharp at much further lengths both closer and further than what I measured, BUT it isn't TACK sharp out of those ranges. (for me).
Again, I've seen a lot of Letus footage, and I see the same issues as my footage. I can pretty much guess what lenses were used, and conclude why certain shots are soft.
I haven't seen any infinity focus being SHARP with the Letus/HV20 kit.
If anybody has please post it here so we can discuss. Please no EX1 footage. Thats a different animal all together for some reason. I'm not a techy, so plz excuse any possible ignorance!!
Alright. I also just checked the Letus direct forum ( what a sham!! ).
Letus has bad customer service. To fix (supposedly) the back focus on the mini you have to open it up, and align each pin in each boot, manually with'n one 10 thousandth of an inch of the sweet spot, in order to get the right back focus. That means trial and error. A LOT of trial and error. Reports (however few) are that there is no correct per se' consistent setting, so you have to experiment. That means possibly taking apart and putting the unit back together 15 to 20 times in a row before getting it set right.
Not only is that a lot of work BUT, that leaves a bunch of room to break something or smudge the screen. I may try to fix it again, ONE time, and hopefully it works, but I'm considering just dealing with the back focus problems and shooting with'n the ranges I measured. I really don't want to break something. This is the main reason I bought the D90. I wanted good calibration, which it has. But the look isn't as rich IMO.
Yeah, I don't think I want to try and fix it. With my luck I'll break a 1500 dollar adaptor and Letus will never fix it......
I'll probably just deal with it and keep looking into better options.
I would just call them. It can't hurt to talk to them and see if they'll fix it. Whether or not there's a problem with the design, they specifically advertise the fact that it supports infinity focus. If you call them and they won't take responsibility for it, then you should start making a stink about it, not before.
I couldn't resist, so I took it apart and adjusted the back focus. It took about 10 attempts and now it's a lot better. It goes a scoach past infinity focus, but just a scoatch. So I have to turn the focus ring back a tiny,tiny, bit for infinity focus once I get to the far end. It's there though. It was THE most stressful thing I've ever done. 2 of the pins came out of the sockets, and I had to push them in pretty damn hard to get them back in. Hopefully I did it right, and didn't damage anything. I guess I'll know after I use it a while, but for now the back focus is set properly. I'll let you know in a couple days if it stays or slips out.
I have no idea what will happen, but I finally can use my wide angles for things other than extreme close-ups. I'll test tomorrow and get back to this thread.
So everybody can scratch my initial post, (except if you don't want to bother adjusting back focus). If that is the case then you'll need to measure your focus range for each lens, at least. Wish me luck that the adaptor is repaired!!
God I hope it's right here on out.
But that wont protect your eyes from my bad focusing. Remember, it took me over a year to even notice!!