Edge to Edge Sharpness on LE

[Lenilenapi]

Tim,
I intend to run some comparisons on this as soon as I get my Brevis Flip. But I think you are right to be concerned and its one of the reasons I got annoyed when people made all sorts of claims about how sharp the Letus was.

However it still may be better than you think. Try using it at its compromise focus position between the corners and the center. if it is inherently as sharp in the center as you felt then the compromise may not be bad at all.

I think this is not unique to the Letus so don't dump it before trying these things out.

Lenny Levy

 

[taormina]

It was sure sharp in the original footage posted here. I for one would love to see the footage where it wasn't sharp.

Timur - explain yourself with that pregnant remark.

 

[Park Edwards]

I say, build one for your own liking.

 

[Kholi]

Tim,
I intend to run some comparisons on this as soon as I get my Brevis Flip. But I think you are right to be concerned and its one of the reasons I got annoyed when people made all sorts of claims about how sharp the Letus was.

However it still may be better than you think. Try using it at its compromise focus position between the corners and the center. if it is inherently as sharp in the center as you felt then the compromise may not be bad at all.

I think this is not unique to the Letus so don't dump it before trying these things out.

Lenny Levy

Can someone please tell me what it is you're compromising by zooming in to the correct numbers?

I'm at a loss as to what this compromise is, honestly. If you're not trying to achieve an accurate 35mm FOV, sure, there's a compromise. If you are, then the extra zooming range is EXTRA.

I honestly don't really care, the only softness I get is from using sub-par glass and that's why I got a PL mount. You wanna be "pro" about everything, go grab yourself a PL mount and make sure it's not your glass.

I'm not trying to flame or anything like that. I want to know where the compromise is in zooming in to a proper 35mm crop factor.

It was sure sharp in the original footage posted here. I for one would love to see the footage where it wasn't sharp.

Indeed. Use it properly and you get proper results.

 

[Dennis Wood]

All I can claim for the Brevis flip you're getting Lenny is that in all tests (and so far consistently across our user base), it's sharper edge to edge than the non-flip version. So if you were happy with the non-flip edge to edge, this is much better On our XH-A1, it's nearly perfect.

 

[Tim Naylor]

I can't give you scientific evidence because I see what I see, explained it to you all and showed you charts (Ryan Walters) which pretty much replicate the problem. If any of you have a fix, I'll take it. Otherwise, it's off to market.

It's not an alignment issue since the problem isn't lopsided. It's something I haven't encountered with my SG, once with an old Brevis (sounds like they solved it).

Focus position will not solve this. You cannot get the outside edges sharp no matter what the stop is.

It will do the same on any glass. You got a fix, send it to me. Otherwise, please don't get your knickers in a twist and act as sensitive as an HPX 500. Tired of nimrods taking it personal. THey're just tools.

Just need some answers.

 

[Kholi]

I can't give you scientific evidence because I see what I see, explained it to you all and showed you charts (Ryan Walters) which pretty much replicate the problem. If any of you have a fix, I'll take it. Otherwise, it's off to market.

It's not an alignment issue since the problem isn't lopsided. It's something I haven't encountered with my SG, once with an old Brevis (sounds like they solved it).

Focus position will not solve this. You cannot get the outside edges sharp no matter what the stop is.

It will do the same on any glass. You got a fix, send it to me. Otherwise, please don't get your knickers in a twist and act as sensitive as an HPX 500. Tired of nimrods taking it personal. THey're just tools.

Just need some answers.

You didn't state that you couldn't get it sharp by zooming in, did you?

Nor did you state any of those other facts. You jumped on the forum and asked about edge-to-edge sharpness, were told that you're amongst the very few experiencing.

Gave you the perfect reason why Ryan's tests were soft AND his Zeiss tests were still sharper.

Could care less about the tool and more about the truth: truth is that you didn' divulge more information. You took your usual high-and-mighty route (yeah, we know you're a "legit" DP) and ignored suggestions right off the harbor.

By the way, I LOL'd at your insult with a camera-geek twist; classic.

 

[taormina]

I can't give you scientific evidence because I see what I see, explained it to you all and showed you charts (Ryan Walters) which pretty much replicate the problem. If any of you have a fix, I'll take it. Otherwise, it's off to market.

It's not an alignment issue since the problem isn't lopsided. It's something I haven't encountered with my SG, once with an old Brevis (sounds like they solved it).

Focus position will not solve this. You cannot get the outside edges sharp no matter what the stop is.

It will do the same on any glass. You got a fix, send it to me. Otherwise, please don't get your knickers in a twist and act as sensitive as an HPX 500. Tired of nimrods taking it personal. THey're just tools.

Just need some answers.

I'm not going to waste my time convincing you not to sell your extreme. You no like? No problem. Just don't badmouth the product 'cause there's nothing wrong with it.

 

[Lenilenapi]

Hmm can't get the edges soft no matter what? I don't recall that. But I will look again. Seems to me I could get pretty good corners though the center would soften up. Are you talking about the bvery edges or just the general corner areas?

Are you using it on an HVX? What zoom & focus numbers?

I'm wondering if there is anything wrong with your unit.

Have you put this up on a chart? If so why not post a grab. ( Did you post something here or can give me a link to Ryan's - maybe I just missed it here.) That would tell us if it worse than the others out there. If its defective there's no point in just junking the whole product.

 

[Arrik]

act as sensitive as an HPX 500.

Hahaha, c l a s s i c indeed.

 

[Tim Naylor]

Are you using it on an HVX? What zoom & focus numbers?

I'm wondering if there is anything wrong with your unit.

Have you put this up on a chart? If so why not post a grab. ( Did you post something here or can give me a link to Ryan's - maybe I just missed it here.) That would tell us if it worse than the others out there. If its defective there's no point in just junking the whole product.[/QUOTE]

Take a look at this.
www.timnaylor.com/edgetoedge. This replicates to the tee the problem I'm having. Look at it and you'll understand what I'm dealing with.

I don't have focus charts at my disposal to replicate this test nor do I feel the need since this replicates the problem I'm having.

I am just relaying my experience with my LE. I noticed it in when shooting a two shot with people on the same focal plane. The actors at the outside of the frame were significantly softer than when there were at the center. We were shooting at a 2.8 on a Nikon 50mm 1.4. This lens does not exhibit these problems on my still camera.

Didn't mean to "badmouth" all the well intentioned LE's out there. Reckon I didn't know them were fighting words. Seriously, let me amend things before the posse mounts. I'm junking my LE. Haven't had time to test everyone elses. Maybe next week.

I really want it to work. And if anyone knows anything about this issue, I'm all ears. Selling gear is a drag.

 

[Ted Spencer]

I'd like to see edge-to-center focus examples from other users, even if it's not from an industry standard chart. Just something that's inherently sharp (like a full two-page from the New York Times) shot at an appropriate distance with and without the LEX. If others' results are satisfactory then we can assume the problem is with Tim's (and, I suppose, Ryan's) unit. If not, then Letus's bold claim of "the best edge-to-edge sharpness in the industry" (http://www.letusdirect.com/cart/Letus-35-Extreme-p-6.html) has to be called into question.

We need more data points folks. Let's find out what's really going on...

 

[Lenilenapi]

Tim,

I saw the chart you posted and my reaction is that it could easily be the result of focusing too close.

On my HVX I can start getting the center of the LE is focus somewhere around 5.76 feet, I still have it in focus after 6.14. (I'm doing these numbers from memory by the way so I could be a little off or have the wrong decimals - maybe its even meters).
At 5.7 or so I am getting the center in focus and after 6.14 I start to lose the center and I only have the corners. When my center is sharpest my corners are still a bit soft and vice versa.

I have tended to set my focus at either 6.04 or 6.17 going for the best compromise between the center and the corners. I'm not sure I always end up with the same numbers. I used to think 6.17 but last time it was 6.04.

The chart you displayed looked to me exactly like it was focused before 6' . The reason I'm a nut about having a chart on the set is that I can't imagine how one could be really sure whether you've got the optimum focus point or not without one.

I'll grant that I'm a touch obsessive about it, but what happened to you on a shoot might never have happened if you spent $15 on a chart at Kinko's and checked it a few times during the day. You would know exactly what was happening.

I'm emailing you a focus chart file. Before you junk your LE, Put it on a CD, bring it to Kinko's and make a 3- 4' blow up - then tape it to a piece of foam core. It will be the best investment you make this year.

Lenny Levy

 

[Kwan]

Ted,
If you get chance, Come by my studio 01/28 @6PM (DVXUSER MEETING). We can test this issue.

 

[Lenilenapi]

As long as I'm on a soapbox about this I'm very curious:

Can we have a little poll here as to how many adapter users have or carry around a focus chart?
Those of you who don't, how do you focus your adapter on the set?

Call in to this address now!
Our lines are open and operators are standing by!

If you think its a ridiculous waste of time we want to hear from you as well.

Lenny Levy

 

[jenningsp]

i focus my adapter buy stopping my SLR lens down all the way and pointing it at a bright light.... make sure your adapter is off at the time because i once spent ten minutes trying to work out why my camera wasn't focusing properly, halting every thing on set ..... the bright light can be anything, the sun, a stage light, a normal house light, a torch, just make sure it's BRIGHT.
this makes the grain of the adapter extremely visible and i mean visible.
then i use expand focus and focus on the grain as best i can (you can use auto focus, it works out about the same). that's it. it's perfect everytime

 

[Lenilenapi]

Tim, I'm sorry I just looked back and noticed you said you can'tget the corners sharp no matter what you do with focus. That I don't understand actually. I can on my Letus.

jenningsp - Thanks for responding - my guess is we'll hear a lot of different methods.
I use the expanded focus sometimes as well, but am always wary that the expanded focus is always looking at the center of the GG only. If I'm doing that I try to err very slightly to the far side of best focus.

Lenny

 

[Kholi]

Same way as Jennigs. til you see the grain, auto focus on the grain. Set.

Leni can I ask, please, what Zoom you have your LE set to at all times? 5.67 is definitely different focus for me.

I get hair sharp/ tack sharp @ 27.3 Focal/zoom and 5.25/38 Borderline on the HVX.

That's 17mm and up. Anything zoomed in more is gold.

Edit here: Leni, the focus chart would be good if the actual HVX focus didn't fluctuate when between focal lengths. Focusing with the taking lens isn't as important as focusing on the ground glass first, right? So, finding tack-sharp focus on the GG first, then gaffing it down tends to fair better than a focus chart. For me anyway.

 

[Kholi]

Didn't I "badmouth" all the well intentioned LE's out there. Reckon I didn't know them were fighting words. Seriously, let me amend things before the posse mounts. I'm junking my LE. Haven't had time to test everyone elses. Maybe next week.

I really want it to work. And if anyone knows anything about this issue, I'm all ears. Selling gear is a drag.

It's not about you badmouthing anything. You didn't tell anyone you zoomed in, did you? We don't care if you sell it, it's not hurting us. But if you come to the forum asking for help, share information and what you've done to test the issue. If you come to the forum to ask for help, people give you suggestions, let us know how they turned out so we can all sleuth with you; that's what you've requested.

Admittedly, I can come off brash as well but I do know there are better ways to say things.

 

[Easom Aerospace]

Edge to Edge sharpness concerning different cameras! I will stand up for the LE in regards to versatility. The product seems to work quite well with a variety of vedeo cameras. Does it work perfect with all cameras? No. I've been working with optical instruments for about 2 decades. I've learned that when developing a new multi element instrument you have about 5% luck on your side and are governed by about 95% science. Building a Proper DOF adapter is the single most challenging event I've experienced so my congrats to Letus/Cinevate/SGProand all others who have brought great units to the marketplace.

My 2 month goal of producing a proper unit is going on 11 months. 3 months alone in developing a proper Achromat/Condenser combination for the HVX. I was not completely impressed with the look adapters were producing and that is why I decided to make one that works right. My answer was developing camera specific equipment. I've concluded the design, test and build process on units for the DVX and HVX. I'm currently refining a rail mount to properly dock the units to the cameras. I know many here have been holding there breath to see If I will produce some nice HVX footage. I'm filming everything I can today and tomorrow including finals on res charts. So footage is imminent.
If you haven't seen my efforts, here is my thread: http://www.dvxuser.com/V6/showthread.php?t=110922 and a few images of the unit and rod support. These are lightwave 3d design drawings. I'll have pics of the actual unit on my thread soon.

About different cameras. The DVX and HVX, being from the same family, one would think could use the same adapter equally well. Not so. The Unit I developed for the DVX uses a custom Achromat/Condenser and works very impressively with the DVX. The HVX required a whole new custom lens set because it was exhibithing unacceptable edge to edge sharpness issues when used with the working DVX adapter.
Both units now work perfectly well on their respective cameras but will probobly not work equally well on a ZV1 XLU or whatever those things are called. My next tackle is building a proper unit for the XDCAM PMW-EX1
I have an HVX unit shipping to Germany in just a few days and I'm more than anxious for the buyer to use it and give feedback.

Edge to Edge was a an important issue for me and I hope this helps some.

Cory