Sony Ex-1 with new Letus Achromat - Good!

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Lenilenapi

Carbonite Member
I just got my new Letus achromat and quickly put it up on a chart with my Ex-1. Looks very good.

Wide open on the EX and wide open on a Nikkor f1.4 had good corner sharpness and it hit the center and corner focus pretty darn close to the same spot. With this camera that's alot of sharpness.

I think it was still unable to get quite full SLR framing but I'm not certain of that. It might have been close. Looked good at both Z70 and Z90.

Quick tests and I will post the frames much later, not today.

Good job Hien & Co. Thank you very much.

Lenny Levy
 
How do we deal with older Achromate, Should we call Hien and ask for replacement?
 
Lenilenapi said:
Looked good at both Z70 and Z90.

Quick tests and I will post the frames much later, not today.

Good job Hien & Co. Thank you very much.

Lenny Levy
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Wow, z70 would be a really massive improvement from the current z80 that I do. What mm lens was the one you tried? Did you try it with 20mm or 35mm wider lenses?

Sami
 
Kwan said:
How do we deal with older Achromate, Should we call Hien and ask for replacement?
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I emailed Letusdirect's support about a week a go and I have not received any response back. I also sent Aaron a private message in here back in 2/12/08 and so far no response either. That's why I started this thread. It's either they're too busy with making the add-on hardware, too many new orders, or just plain ignoring existing owners until they have filled all those new orders because they'll have to deal with replacing the existing achromate or somehow. It would be nice if we know what the status are.
 
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Even though I own an HVX I'm very eager to see your charts. The EX-1 had one of the worst edge softness issues I've seen yet with the LEX. If the "fixer" really fixes it then one might assume an HVX fix would be even easier.

An HVX/LEX with excellent edge/corner sharpness, along with its other existing virtues, would make me one very happy camper.
 
myCharlie said:
I emailed Letusdirect's support about a week a go and I have not received any response back. I also sent Aaron a private message in here back in 2/12/08 and so far no response either. That's why I started this thread. It's either they're too busy with making the add-on hardware, too many new orders, or just plain ignoring existing owners until they have filled all those new orders because they'll have to deal with replacing the existing achromate or somehow. It would be nice if we know what the status are.
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Any Response?
 
When I did that it became pretty sharp on my HVX tests.

So i don't know if your complaining that that didn't work, or one shouldn't have to do it.

I'll test my HVX new Letus achromat in the next couple of days.

Lenny Levy
 
Lenilenapi said:
When I did that it became pretty sharp on my HVX tests.

So i don't know if your complaining that that didn't work, or one shouldn't have to do it.

I'll test my HVX new Letus achromat in the next couple of days.

Lenny Levy
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I'm not sure exactly what this post refers back to. Could you please clarify? Thanks.
 
Sorry Ted,
I must have erased the first sentence and didn't notice. I was wondering if you had tried finding a midpoint focus on the Letus between the center and the corners, because I'm not aware there is a serious focus problem with LEX/HVX if you do that.

Thus this followed:
When I did that it became pretty sharp on my HVX tests.

So i don't know if your complaining that that didn't work, or one shouldn't have to do it.

I'll test my HVX new Letus achromat in the next couple of days.

Lenny Levy
 
Lenilenapi said:
Sorry Ted,
I must have erased the first sentence and didn't notice. I was wondering if you had tried finding a midpoint focus on the Letus between the center and the corners, because I'm not aware there is a serious focus problem with LEX/HVX if you do that.

Thus this followed:
When I did that it became pretty sharp on my HVX tests.

So i don't know if your complaining that that didn't work, or one shouldn't have to do it.

I'll test my HVX new Letus achromat in the next couple of days.

Lenny Levy
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I now have my LEX along with a new Zeiss 50mm 1.4, and in perliminary testing I found the same kind of issues that Tim Naylor and others have: at wide open on both lenses the focus point is very significantly different for the center and the edges, and the edges are different from each other.

I shot my piano keyboard from a distance of about 5 feet, and placed a few objects on it where the image corners were for reference. I made sure the camera was perfectly centered and purpendicular to the piano. The maximum difference in focal points between the parts of the frame was approximately 12" as indicated on the HVX's LCD!

I did try a compromised mid-point focus setting, but of course it left everything 3-6" out of focus. This is not acceptable IMHO, particularly not for filmout. As Tim pointed out, classic two-shot dialog framing would present serious problems with it, as has been illustrated in numerous screen grabs on this site.

The lens and adapter should be expected to cost some resolution, but it should be much more field-consistent than it is. I'm hoping Letus does the same with the HVX as they did with the EX-1 - an HVX-specific "fixer kit". It appears that such a solution may be in the works. We'll see...

In the meantime, I'm very curious what you find with the EX-1 solution on the HVX.
 
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Ted,

I'm trying to get my head around what your saying and I don' discount it at all, but I'm wondering if you are separating DOF of the 50mm lens from the back focus of the Letus on the HVX.


By the way I freely admit i might be wrong here as I am thinking out loud.

It seems to me that if you focus on the piano at say 5' on the zeiss then I don't think you would have everything from 3 - 6" in focus normally would you? Is there that much DOF?

Anyway - I've been under the thinking that when you find the midpoint focus, you're not reducing or affecting the DOF of the image at all but just making sure that you aren't sacrificing the corners for the center of whatever DOF you were given by the Zeiss.

You would reduce overall sharpness and sharpness would never be completely even across the frame though. Maybe it would be best in a circle about halfway out from center. Actually not bad for a 2 shot. f1.4 is always scary for drama as any assistent will tell you.

Does that make sense?

BTW I've just discovered in looking at my frame grabs that the left side of my EX/Letus frame grabs is softer than my right. I've emailed Hien who told me he thought my prism might be misaligned, so i don't want to post those images if there is a defective prism.

It does bring up an interesting point though. I never noticed this even looking at my chart on a 17" Panny monitor! Granted I was by myself, not looking for it and moving quickly, but I didn't see it until I happened to blow up the frame grabs to full screen on my 24" Dell. In fact I noticed lots of problems including CA, soft corners, etc on all my frame grabs from all the adapters only when I looiked at frame grabs on my computer full screen.

I used to say that all you needed to do was get a chart to see what your lenses are doing. Now i realize you really need to look very carefully and maybe even the Panny doesn't reveal enough. Compare that to getting your new adapter shooting some test in the woods behind your house and looking at an inexpensive monitor. Its easy to miss things that could bite you hard later.

Lenny Levy
 
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Lenny -

Let me see if I can clarify what was again a preliminary finding. I took these steps:

-Setting the LEX up in the recommended way and focusing on the center of the GG while zoomed in, then zooming back out to where the vignetting was gone. I used my 42" plasma screen for this and the rest of the testing.

-Placing the HVX about 5' from and purpendicular to the piano keyboard as described in my previous post, with its iris open.

-Focusing the Zeiss, at 1.4 (open), on the center of the keyboard. It was tack-sharp, but edges and corners were not. Refocusing the Zeiss did not appreciably help.

-Refocused the HVX for the edges of the frame without changing the Zeiss. IIRC, the right edge required about 12" longer focus indication than the center (on the HVX display) to be at its sharpest. It was not as as sharp as the center was at its best, but both lenses should be expected to have some edge sharpness loss, especially wide open. It was certainly acceptable when viewed in that light. The left edge required roughly a 6" increase in HVX focus distance to do the same.

-When focused in either of these ways, the center lost a great deal of sharpness.

-A "compromised" HVX focus length produced a more even, but uniformly quite soft-ish result that I consider to be unsatisfactory (I have made Aaron and Hein aware of this in ongoing discussions that began before my LEX arrived).

-Thus, it would appear (and I'm no expert, so I will happily stand corrected if I'm wrong) that a "fixer" is needed for the HVX, such that it would bring the entire image as close to the same focus plane as possible. Again, I don't expect perfection with open apertures, but it would certainly appear to me (and obviously others as well) that it could be improved a great deal. The EX-1 case seems to be convincing proof of this since its aberrations were evidently much more severe initially, and now, with its fixed achromat and spacer, are nearly gone.

Make sense?
 
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Ted,

-A "compromised" HVX focus length produced a more even, but uniformly quite soft-ish result that I consider to be unsatisfactory
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That's really the critical piece of information. At the midpoint you got a "relatively" even field, but inevitably there has to be a compromise also on overall sharpness. On my tests on a chart with the Letus I didn't find that the overall sharpness (even "compromised" compared to the other adapters was much different so I thought the mid focus was a good solution - but you might be having a different result.

Weren't you with Tim Naylor when you made your comparisons a few months ago?
In that test they decided that the Letus was sharper than the SGPro. My immediate question was - wait a minute are you sure where you were focused? I wonder if the Letus with the compromise focus would now be the same as the SG or softer as you seem to fear.

No doubt getting a perfectly even field would be better of course - I'm just not sure how much is possible in these optics. We really are expecting a lot at f1.4 focused on a postage stamp through a zoom lens.

The pre-flip SGPro ( with its condensor lens) and the Brevis with a Brevis Flip seemed to nail the corners and the center on my HVX - however I'm really not sure the overall sharpness was any better than my Letus test.

By the way - what is your detail setting on the HVX? I keep mine at +2 or even +3 with an adapter. With the Redrock I had it at +7!


Incidentally zooming in all the way on the HVX for your initial focus is not recommended in my understanding. I don't think the zoom lens is expected to track focus once you put the achromat on. Anytime you change the zoom, you need to refocus. So find the zoom point you want and then focus.

As I reread you post i am concerned that your Right side and your Left side were different. They should be the same. That is what i noticed on my EX-1 / Letus tests and I am sending mine back to Hien for a "tune- up". Perhaps that's part of your problem

I would suggest what I say over and over again here - Blow up a chart - and shoot some tests. Its absolutely the only way to know what the hell your lens is doing! A piano is for playing music not testing lenses.

Do you play by the way? ( I play sax - more fun than shooting charts - but the d____ charts have kept me away from my axe!)

Lenny Levy
 
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Lenilenapi said:
That's really the critical piece of information. At the midpoint you got a "relatively" even field, but inevitably there has to be a compromise also on overall sharpness. On my tests on a chart with the Letus I didn't find that the overall sharpness (even "compromised" compared to the other adapters was much different so I thought the mid focus was a good solution - but you might be having a different result.
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In my humble opinion it can be greatly improved by customizing the optics a bit. The results on the XH-A1 look fine right out of the box and the EX-1 fix is very effective. Thus it would seem that an HVX fix should be doable too.

Weren't you with Tim Naylor when you made your comparisons a few months ago?
In that test they decided that the Letus was sharper than the SGPro. My immediate question was - wait a minute are you sure where you were focused? I wonder if the Letus with the compromise focus would now be the same as the SG or softer as you seem to fear.
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Yes I was there at Tim/Kwan's test. The LEX was sharper than the SGPro to my eye, but we only looked at center sharpness. None of our "radars" were up yet about edge/corner issues (and in fauirness to Tim, as an SGP owner, he didn't have any). It was only later that Tim and the rest of us caught it, which to the best of my knowledge led Tim to sell his LEX.

And yes - I was focused tack-sharp in the center as I previously mentioned. The HVX/LEX/Zeiss combo looked fabulous in the center, and just fine anywhere as long as the HVX was spot-focused *there*. As to a "compromised focus" setting being equivalent to the SGP's center softness vs the LEX - no way. On a scale of 1-10, if the LEX's center focus is 10 then the SGP's might be 9. The LEX's right corner focus (when it's optimized for the center) might be about a 5, and the "compromised focus" might average out to about a 7 or so. Very unscientic numbers btw - imagine we're sitting at a bar having this discussion along with politics and sports : ) Point is, we're talking about a *much* bigger difference.

No doubt getting a perfectly even field would be better of course - I'm just not sure how much is possible in these optics. We really are expecting a lot at f1.4 focused on a postage stamp through a zoom lens.
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Again, I'm trying to allow for the lens/aperture issues in the evaluation. The edges *will* be softer wide open, no doubt. But if they don't get a lot sharper than they are now, my LEX will be following Tim's...

The pre-flip SGPro ( with its condensor lens) and the Brevis with a Brevis Flip seemed to nail the corners and the center on my HVX - however I'm really not sure the overall sharpness was any better than my Letus test.
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Tim, Timur Civan and others report satisfactory e2e on the SGP as well.

I had a chance to briefly play with an un-flipped Brevis more recently at another meet at Kwan's studio (I forget whose rig it was), and found some edge sharpness issues there as well, but seemingly less than what I experience here with my LEX. Again - an unscientific observation at best, but perhaps relevant, especially since it corroborates with your findings.

By the way - what is your detail setting on the HVX? I keep mine at +2 or even +3 with an adapter. With the Redrock I had it at +7!
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My default is +2

Incidentally zooming in all the way on the HVX for your initial focus is not recommended in my understanding. I don't think the zoom lens is expected to track focus once you put the achromat on. Anytime you change the zoom, you need to refocus. So find the zoom point you want and then focus.
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I refocused the HVX to get the best results at any given point in the field. I only started with zoomed center focus. Zoom setting stayed at the no-vignetting point once I had it.

As I reread you post i am concerned that your Right side and your Left side were different. They should be the same. That is what i noticed on my EX-1 / Letus tests and I am sending mine back to Hien for a "tune- up". Perhaps that's part of your problem
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The HVX's well known imager centering problem is the likely culprit there.

I would suggest what I say over and over again here - Blow up a chart - and shoot some tests. Its absolutely the only way to know what the hell your lens is doing! A piano is for playing music not testing lenses.
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I will. But a piano keyboard provides a nice set of identical sharp, contrasty edges in a perfectly straight focal plane. A pretty decent test subject, IMO. And it was right across from the plasma screen!

Do you play by the way? ( I play sax - more fun than shooting charts - but the d____ charts have kept me away from my axe!)
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Not professionally, but yes. I use in in my recording studio business mainly. I also write songs on it.
 
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