Edge to Edge Sharpness on LE

Thanks for the focus chart Lenni,

You're right it should be part of any adaptor owner's kit. What can I say, I come from the "spoiled by my AC" era (loaded with every tool and chart I could ever need). Now that I'm a gear owner, I'm beginning to see this is an absolute necessity.

I'm going to conduct some tests tomorrow and perhaps Tuesday. It's don't think it's a ground glass focusing issue. Like most of us, using these adaptors, my AC (Timur) and I are super obsessive about getting as much of the GG in focus to the point we do it every morning before we shoot (you never know how temperature changes can effect optics - it's an old habit from B mount cameras, check your backfocus in the morning, check again when everything acclimates).

Hopefully I'll have something to post by Wed. I'll also test the E to E of my SG as well.

My apologies to all if I come off as an ass at times. I'm just at the point where I lose patience with QC issues for anything I pay more than a G for and there've been quite a few. The real shame is that virtually all the QC problems I've had with adaptors come down to the same core problem - lack of rigorous beta testing. I've offered my testing services before to other manufacturers but for whatever reason, they never take me up on it. Not looking for a free adaptor, just looking to help get a great idea right. Anyway, back on topic.

I rue the day for an adaptor that has no "issues" that should've been caught in beta.

I'll test it. Post the results and hopefully someone has some insights. We'll see how it all goes.

PS. Lenni, thanks for the charts.
 
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Interesting. You think the flip module may have something to do with this. Eitherway, I'll send the results to LE and see what they suggest. So far, they've been great at getting back to me and rectifying any issues I've had with my LE.
 
Tim,
Actually, No I'm not suggesting that the flip is the problem. i have no idea what's up with the optics. i just seem to recall that SG was pretty flat, but i didn't test carefully.
Of course that did have a condensor added for that purpose.

Hey here's a question for you since you also have a background in film lenses. My next big beef is going to about back focusing lenses. Like you I am annoyed that every single adapter I've owned had the Nikon back focus off. In re setting them, I've been finding the point where the 35mm lens is sharp when the focus barrell is turned all the way to full infinity. This sometimes takes it past the infinity mark. This seemed to be working fine, and the focus marks on the barrell seem like the generally correct distances but I've noticed that my 80-200's (both Tokina and Nikon) don't track perfectly. i have to adjust the focus slightly when I change zoom. My 28-70 Tokina looks Ok though.

I understand that some still lenses(maybe only the zooms) are designed so the barrell turns past infinity. If that is so then my whole system is screwed up. Maybe I should be looking for a backfocus that allows my 80-200 to track, and assume that that is the correct distance.

Some of the manufacturers have told me to measure a distance like 10 feet and set the backfocus so that the lens barrel is at 10' when that distance is in focus. I don't trust the barrell markings though and that just sounds wanky to me.

I keep meaning to ask a camera repair tech, or just go to my local film rental house and ask to use their collimator.

Any thoughts about that.?How does your Nikon 80-200 track?


Lenny Levy
 
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I don't own an 80-200. Ask Kwan. I only have primes and have to re-set the back focus in my LE to get infinity to stay sharp. Hien sent me instructions and will give it a shot today. The method of focusing on a far distance is not a bad idea if it gets all your distances to correspond to a tape measure.

With film lenses, we tape/eye test everything and if the camera's off they fix it and if the lens is (usually the case) it gets recollimated or they swap it out. This why we schedule a whole day or more to check out.
 
Tim Naylor said:
Thanks for the focus chart Lenni,

You're right it should be part of any adaptor owner's kit. What can I say, I come from the "spoiled by my AC" era (loaded with every tool and chart I could ever need). Now that I'm a gear owner, I'm beginning to see this is an absolute necessity.

I'm going to conduct some tests tomorrow and perhaps Tuesday. It's don't think it's a ground glass focusing issue. Like most of us, using these adaptors, my AC (Timur) and I are super obsessive about getting as much of the GG in focus to the point we do it every morning before we shoot (you never know how temperature changes can effect optics - it's an old habit from B mount cameras, check your backfocus in the morning, check again when everything acclimates).

Hopefully I'll have something to post by Wed. I'll also test the E to E of my SG as well.

My apologies to all if I come off as an ass at times. I'm just at the point where I lose patience with QC issues for anything I pay more than a G for and there've been quite a few. The real shame is that virtually all the QC problems I've had with adaptors come down to the same core problem - lack of rigorous beta testing. I've offered my testing services before to other manufacturers but for whatever reason, they never take me up on it. Not looking for a free adaptor, just looking to help get a great idea right. Anyway, back on topic.

I rue the day for an adaptor that has no "issues" that should've been caught in beta.

I'll test it. Post the results and hopefully someone has some insights. We'll see how it all goes.

PS. Lenni, thanks for the charts.
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Maybe it's just an off unit? I would like to hear who else (aside from Leni) is having edge to edge sharpness issues? I did notice edge softness and vignetting at a time when I honestly wasn't zoomed in far enough, since has been corrected and I haven't seen any.

Disjecta's stuff looked edge to edge to me. Lots of trees and leaves and everything was as sharp as could be when dealing with extra glass. I haven't done any resolution charts, either, but I suppose I could? I know Luis Caffesse has and when he strapped on Zeiss glass lots of things improved that he thought wrong with the unit, hence his purchase.

I'm curious as to if you own a PL mount for your SGpro or Letus. You're a stickler for quality it seems, have you used any pro glass on either unit?
 
With the Letus, typically I zoom in only far enough to get rid of vignetting which is already considerably farther than my SG or Brevis. That seems to be about 23.4" . I haven't tried zooming in farther to see if that helps corner to center issues. Even if it does though i'm not sure I would want to because I want to able use the full field of view on my lenses. I think I am probably in at least to Academy right now, though I don't care about the academy framing the way Barry does. I don't care about it at all actually.

Only use Nikon lenses for expense reasons. I would consider a PL mount in the future if I had a client that wanted to pay for the rental. This issue has nothing to do with the lenses though. The 80-200 zoom is plenty sharp in the corner if I change the focus on the video camera.

Ryan Walters test of the 50mm Nikon vs. Zeiss has never looked right to me since I always got better corner focus from my own Nikons.

Lenny Levy
 
Lenilenapi said:
With the Letus, typically I zoom in only far enough to get rid of vignetting which is already considerably farther than my SG or Brevis. That seems to be about 23.4" . I haven't tried zooming in farther to see if that helps corner to center issues. Even if it does though i'm not sure I would want to because I want to able use the full field of view on my lenses. I think I am probably in at least to Academy right now, though I don't care about the academy framing the way Barry does. I don't care about it at all actually.

Only use Nikon lenses for expense reasons. I would consider a PL mount in the future if I had a client that wanted to pay for the rental. This issue has nothing to do with the lenses though. The 80-200 zoom is plenty sharp in the corner if I change the focus on the video camera.

Ryan Walters test of the 50mm Nikon vs. Zeiss has never looked right to me since I always got better corner focus from my own Nikons.

Lenny Levy
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I agree on Walters' tests. He doesn't zoom in anywhere near far enough.

I stay at 27.3 myself, and you're probably right about not being able to use the full FOV. My own thinking is that "well it's 16:9 anyway, If I want a wider FOV I'll use a wider lense to compensate or move the camera back.". If that keeps image quality up then I guess it's the trade-off.

I wonder how many people can tell the difference (DVXusers) between the lenses at different focal lengths? Or how much it might matter.
 
It only matters if you want wide shots. I'll try zooming in more, though you also lose more light at the open aperttures.
 
Lenilenapi said:
It only matters if you want wide shots. I'll try zooming in more, though you also lose more light at the open aperttures.
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Absolutely. That's a very good point and something you have to consider. Just another trade-off. I've got some wide shots to show here in a few, when I get a chance to offload cards and compress reasonably.
 
Kholi said:
Maybe it's just an off unit? I would like to hear who else (aside from Leni) is having edge to edge sharpness issues? I did notice edge softness and vignetting at a time when I honestly wasn't zoomed in far enough, since has been corrected and I haven't seen any.

I'm curious as to if you own a PL mount for your SGpro or Letus. You're a stickler for quality it seems, have you used any pro glass on either unit?
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How far do you zoom in (in numerical value - not feet/inches or metric) on the HVX ? I usually have mine set around 78 or so. I'm worried that if I go in tighter, I lose more stop.

Regarding PL mount, when I work with productions that can afford to rent PL mount lenses, production usually has enough money to let me rent a better camera as well (Varicam, etc). The whole low cost adaptor with still lenses for my market fills an certain niche where people want a cinematic quality for used car prices. However, I've considered buying a PL mount for one of my adaptors since I know the job that's somewhere in between will pop up or just for my own projects.

The other issue with adaptors on an HVX comes down to light. I found myself often lighting with more than twice the light as I would with a Varicam and PL lenses. Sometimes this can lose any savings you had with a cheaper camera. Last project I did, I probably could've shot it with half the wattage on a Varicam. If the lighting package was a tad bigger, I would be on that threshold where it may be cheaper to go with a better camera and smaller lighting package.

This is why I want the EX to work.

Back on topic. Anyone test a flip on the SG?
 
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Tim Naylor said:
How far do you zoom in (in numerical value - not feet/inches or metric) on the HVX ? I usually have mine set around 78 or so. I'm worried that if I go in tighter, I lose more stop.

Regarding PL mount, when I work with productions that can afford to rent PL mount lenses, production usually has enough money to let me rent a better camera as well (Varicam, etc). The whole low cost adaptor with still lenses for my market fills an certain niche where people want a cinematic quality for used car prices. However, I've considered buying a PL mount for one of my adaptors since I know the job that's somewhere in between will pop up or just for my own projects.

The other issue with adaptors on an HVX comes down to light. I found myself often lighting with more than twice the light as I would with a Varicam and PL lenses. Sometimes this can lose any savings you had with a cheaper camera. Last project I did, I probably could've shot it with half the wattage on a Varicam. If the lighting package was a tad bigger, I would be on that threshold where it may be cheaper to go with a better camera and smaller lighting package.

This is why I want the EX to work.

Back on topic. Anyone test a flip on the SG?
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We're not off topic, LOL, no worries.

I can't tell you what the numerical value is, I haven't had the camera switched to that in so long that I can't even remember how to guesstimate. Switch over to feet/mm setting if you get a chance and zoom in to 27.3. Set your Focus to 5.38. Then, switch back over to the numbers and see what you get. Tell me ,as well, because I have NO idea and my Camera's at home at the moment.

Trust me, Naylor, I know what you mean about the light. On the Where the Heart Lies shoot, they had an HMI and a 600watt Arri lighting one scene. Two SGpro's opened wide on both ends (taking lens and camera) and they had GREAT exposure. However, I was shooting BTS with the Letus EX and stopped down to 4 and 4 (Taking and Camera) was STILL just about over exposed. Granted, I like the SGpro's image rendering and can see places where it's a bit more pleasant (bokeh) than the Letus. Which is why I would love to have both. Til someone drops a unit (i'm sure it'll be more expensive) That takes everything we want and crams it into a smaller piece, of course.

But being able to shoot with less light has been a real selling point with my gear. I have personally turned a host of guys away from the P+S technik here in my area after letting them rent my LetusEX.

You WILL lose a little more light when zooming in. No doubt, I've seen it and I've actually used it to my advantage outdoors when I couldn't stop down any further on the lens without seeing grain.

Instead, I strapped on a Wider lens, zoomed the camera in to mimic the telephoto crop, and evened out the light that way. Just about figuring the gear out, I suppose.

I've just recieved my LetusEx PL mount and on Wednesday I get to pair it with some Posi-Lock Zeiss Standards. I'll sneak some stills from production and pictures of the unit if I can.

Update us on your findings with the flip and the Letus after your tests.
 
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Tim Naylor said:
How far do you zoom in (in numerical value - not feet/inches or metric) on the HVX ? I usually have mine set around 78 or so. I'm worried that if I go in tighter, I lose more stop.

Regarding PL mount, when I work with productions that can afford to rent PL mount lenses, production usually has enough money to let me rent a better camera as well (Varicam, etc). The whole low cost adaptor with still lenses for my market fills an certain niche where people want a cinematic quality for used car prices. However, I've considered buying a PL mount for one of my adaptors since I know the job that's somewhere in between will pop up or just for my own projects.

The other issue with adaptors on an HVX comes down to light. I found myself often lighting with more than twice the light as I would with a Varicam and PL lenses. Sometimes this can lose any savings you had with a cheaper camera. Last project I did, I probably could've shot it with half the wattage on a Varicam. If the lighting package was a tad bigger, I would be on that threshold where it may be cheaper to go with a better camera and smaller lighting package.

This is why I want the EX to work.
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I agree completely on all points.

Kholi - Are you saying that a crew with HVX's & SGPro's were wide open on both camera and 35mm lens - and you with the same camera and a Letus were at f4 on both camera and 35mm lens???
If I read you right I find that hard to fathom as there is not that much speed difference between the adapters. Must have been other factors at work - Gammas , shutter speeds , gain something...


Lenny Levy
 
Lenilenapi said:
I agree completely on all points.

Kholi - Are you saying that a crew with HVX's & SGPro's were wide open on both camera and 35mm lens - and you with the same camera and a Letus were at f4 on both camera and 35mm lens???
If I read you right I find that hard to fathom as there is not that much speed difference between the adapters. Must have been other factors at work - Gammas , shutter speeds , gain something...


Lenny Levy
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F4 on the Vivitar 35mm 2.8, F4 on the HVX. Zoom was at 30.1mm (I don't like zooming out to 27.3 anymore, honestly. I love the FOV as I go in further. Just different tastes.) Same shutter. 180.d. They had a Set of Nikons that were ten times better than my garbage old-school beginner photographer Vivitars. I walked around with the Vivitar 35mm on it all day aside from when I put the 2.5 on and I didn't even use that one.

It's not to discredit ANY adapter, as the SGpro image was killer (Geoff Resiner, DP and Matty_G AC were killin' it as usual). Just that the same light was too much.

Check the Where the Heart lies BTS to see.
 
As a not-yet-but-soon-to-be LEX owner, I haven't got any hands-on experience (aside from participating in Tim's Naylor and Kwan's NYC test a few weeks ago), but I noted something on Letus's site that I thought might be relevant, even though it's primarily intended to address the off-center imager issue. Here's the quote:

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"The frame size in the Letus35 Extreme is 46x30, much larger than the 35mm full frame size (36x24), and much much much larger than 24x18 (academy frame size).

The purpose of 35mm lens adapters are to achieve 35mm film frame size, which is 24x18. The still camera 35mm frame size is 36x24, which is called "full frame". The Letus35 Extreme is at 46x30. This allows a user to zoom in (to compensate for shifted image sensors etc.) and still get a 36x24 "full frame" image. This is still larger than academy frame size of 24x18 which is the size most look to achieve.

With the 46x30 frame size in the Extreme, there is enough extra frame to achieve an academy frame size of 24x18 or even the full frame size of 36x24 even with a shifted image sensor."

------------------

So, shifted image sensors aside, is it possible that some of the edge sharpness issues people are having are due to the LEX having an intentionally oversized internal form factor? Is it possible that if the zoom level were set to the expected (by Letus) framing point, rather than just inside the vignetting point, which which might be too wide due to the oversized frame, that the edge sharpness problems would at least diminish considerably (if not altogether)?

Or am I misinterpreting the above quote?
 
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Kholi said:
F4 on the Vivitar 35mm 2.8, F4 on the HVX. Zoom was at 30.1mm (I don't like zooming out to 27.3 anymore, honestly. I love the FOV as I go in further. Just different tastes.) Same shutter. 180.d. They had a Set of Nikons that were ten times better than my garbage old-school beginner photographer Vivitars. I walked around with the Vivitar 35mm on it all day aside from when I put the 2.5 on and I didn't even use that one.

It's not to discredit ANY adapter, as the SGpro image was killer (Geoff Resiner, DP and Matty_G AC were killin' it as usual). Just that the same light was too much.

Check the Where the Heart lies BTS to see.
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Do you not find than when you stop the 35mm lens down to F4 and below, that the vibrating GG becomes apparent?

I see it quite visibly here with snow all around. And i understand its easier to see in snow, but i thought perhaps that F4 might be a limit?
 
PaPa said:
Do you not find than when you stop the 35mm lens down to F4 and below, that the vibrating GG becomes apparent?

I see it quite visibly here with snow all around. And i understand its easier to see in snow, but i thought perhaps that F4 might be a limit?
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F4 is fine for me. Going to 5.6 is where I see the grain. Biggest drawback of the vibrating GG, unfortunately.
 
What zoom length on the LE approximates 24 x 18 FOV?

Also, I never got that big a diference in exposure bet my SG and LE. Half a stop at most
 
Tim Naylor said:
What zoom length on the LE approximates 24 x 18 FOV?

Also, I never got that big a diference in exposure bet my SG and LE. Half a stop at most
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Saw it with me own eyes. I won't rule out a mistake, but I know for sure that the entire day I was 2.8 - 4 on camera and 2.8-4 on taking side. I guess it doesn't matter that much, if I get a chance to do some wide-wide tests (all ends wide between SGpro and EX) I will. Or at least both matched in all settings, aperture, etc.

I'm not sure what Zoom's 24 x 18... but I'm having interesting things go on with these PL Zeiss Standards I picked up (rental) today.

The 40.4mm Zoom setting I've been using works for 16mm and up on the prime set. I can't go wider on the 16mm than that because the lens has a lot of vignetting and a huge hot spot. The 35mm's hotspot is actually worse than the 16mm, but 40.4 all around works for the lenses.

Anyone got thoughts?
 
Huge Update from my end:

I see what Tim is talking about, now. And, also, it's with PL Lenses. I think I have a theory as to WHY this is happening. Not just with the Letus, but with the Brevis as well.

Zooming in doesn't correct the issue, and it's abhorrently apparent with a few lenses.

What's funny is the 35mm Zeiss (32mm actually) does it but my Vivitar 35mm 2.8 doesn't. The major difference (aside from obvious build quality) is that the Vivitar has a larger piece of glass than the 32mm Zeiss PL Standard. There's also a MASSIVE hotspot in the Zeiss standard, I'll have pictures of it tonight in comparison to my 35mm SLR lens.

It SUCKS hardcore but It may not be a property of the adapter or ANY adapter at that (or mostly).

The 32mm has a VERY tiny piece of glass. VERY VERY tiny in fact, and my Vivitar has a very large piece of glass, allowing me to get into the sharp spot anywhere from 27.3mm on the HVX's end. So it turns out (if I'm right) that you actually wanna get the sharpest glass with the LARGEST glass, so that your camera can use a larger portion of the "good part".
 
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