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Old October 24th, 2007, 07:22 PM   #1
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Looking at the Letus Extreme

How well does the Letus perform with wide angle lenses? Does anyone have any footage or experience with attaching like a 28mm or wider lens to it?
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Old October 25th, 2007, 12:27 AM   #2
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Steve, the Letus performs very well with wide lenses the only caveat is this...you absolutely must use an external monitor with wide lenses because the depth of field is much greater and it is virtually impossible to see exactly what is in focus using the camera's LCD. It can be done and I have done it, but I would not recommend it.

Footage I have shot with the 28mm f2.8 is beautiful when it is in sharp focus. I just bought a 24mm f2.8 so I'll be testing that too with the release version of the Extreme once I get it.
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Old October 25th, 2007, 04:16 AM   #3
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I'd love to see that footage.

If I'm outside and I've got plenty of light, can I stop down and have more depth of field with the Letus? I mean, there are situations where focus won't be so critical right? I would've thought I wide lens with make focus less of an issue but it sounds like I'm wrong from what you said.
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Old October 25th, 2007, 04:32 AM   #4
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Steven,

On the topic on monitors...

I've been using my PC monitor (Dell) for some testing to do with focus assist. The monitor is extremely sharp and large (24" and wide aspect ratio). The large monitor helps but I have a question that I hope you can answer:

What are the advantages/disadvantages between using a PC monitor (pixel aspect ratio aside), an HDTV and small 7" field monitor (such as the Marshall you use)?

Does 7" really make that much of a difference?

Another thing I've discovered is that peaking has a kind of range, in that while manually focusing when one sees peaking take place one can continue to move the focus ring and peaking will still be effective, however, the subject is in focus at only one point. Is this normal? If so, when you're using a monitor, do you simply "eye ball" the focus or have you got some other technique for achieving sharp focus (quickly)?

Shiv.
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Old October 25th, 2007, 08:31 AM   #5
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Steve, I've already published most of my tests and all of them include shots with the 28mm. Stopping down is not really a viable option with the Letus. It's the same with many other adapters but I'm just going to talk about the Extreme here. If you have a f2.8 wide angle, you could get away with stopping down to about f4 which will help widen your depth of field but if you close down to anything smaller, the ground glass pattern becomes visible. So it's not really practical to do it that way regarding focus. Focus is really tricky with short lenses and there is just no way around it.

Shiv,
I"m not sure what your question is. You ask does 7" make much of a difference. Compared to what? The LCD? Hell, yes. There is no comparison. And remember, Canon's peaking feature can be seen on the external monitor which gives you double help in the focusing department.

You'll also need to clarify your question about peaking. I didn't really understand it. Sorry
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Old October 25th, 2007, 02:34 PM   #6
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Steven,

Thanks for the reply regarding the 7" versus the LCD on the camera. Yes, that was one of the questions.

For some reason, when using an HDTV (19" 720p capable) or my Dell PC monitor, I don't seem to really find much help when it comes to focusing. I mean you see things a lot bigger and all but I can focus just as well (or badly) with the LCD. Maybe less strain and all that. I need to play with it some more.

The peaking issue...
So here is what I'm doing. I've got my PC monitor hooked up (no peaking on the monitor - probably a custom setting I need to figure out), but peaking is on on the LCD view finder on the camera. The focal lenth of the camera lens is zoomed in all the way (no Letus used in this). The camera is pointed to a subject such that the subject (an inanimate object) occupies 1/3 of the screen.

I then start to focus manually and see the peaking appear on the LCD. I then look at the PC Monitor and I can see that the "subject" is not quite in focus. So I continue to turn the focus ring slowly, looking at both the LCD and the monitor. The peaking is still showing on the LCD while on the monitor I can see the subject getting sharper. Conitue turning the focus ring and the subject now begins to go out of focus (seen on the monitor) while the LCD is still showing peaking and eventually stops showing peaking.

Keep in mind when I say "continue turning the focus ring" the movement is very very small, but you can see the focus changing on the monitor going from almost sharp focus to sharp focus to not in sharp focus.

So in other words, peaking gets in the way of sharp focus because it starts peaking just before the subject is in sharp focus and stops peaking when the subject has gone out of sharp focus. In addition, due to peaking, you're not able to see when the subject is in sharp focus.


The other question was basically this: Do "field monitors" (like the Marshall you use) have something special in terms of quality, sharpness etc. that makes them a better choice is that not the case?

Asked another way, if you had the option to use a large "monitor" such as a PC monitor or say a 19" HDTV (720p or 1080p) which would you use (barring the portability and other advantages a small field monitor has) and why?


A 7" Marshall costs $1500 odd, while a 19" HDTV 720p costs $350. But is there a quality difference that I don't understand?
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Old October 25th, 2007, 08:58 PM   #7
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Shiv,

Maybe I can chime in a bit here and help - As for focus assist - ideally you want to have a monitor capable of resolving a 1080i/p picture - you want something ideally that matches the resolution you're shooting at - What Steven is trying to say is that anything larger than the onboard LCD on the A1/G1 is better if it resolves the resolution of the camera - I haven't used a 720p LCD to focus with but take into consideration that the Marshal HD 7"-ers are 800x600 RGB pixels and work very well in the field - I'll get laughed at for this by most but I actually prefer the Ikan 8000HD image to the Marshal and it only consists of 800x480 :) -

Should you use a larger monitor if you have the chance? Absolutely - a great example of this is just about any behind the scenes set footage of newer Star Wars films / Robert Rodriguez films - they use a video villiage - mass amounts of large LCD's / CRT's for critical monitoring - but even on cam, the operator is usually using a smaller LCD - so if the situation affords, use the larger ones - I love the Dell 2405 - stunning picture when calibrated (also take that into consideration) and very useful for stage work that we do when we monitor. Would I use that over the Marshall - absolutely - doesn't work for a lot of what I do though when I'm remote. On a practical set or stage with a crew, you bet I'm using it.

Steven has a link (don't have it handy) on the DVXuser forum wherein he shows off some Letus Extreme footage shot in 24f at a 120 shutter using a 200mm lens (soccer footage) and he's pulling focus without a follow focus (I'm pretty freakin' jealous) - He's spot on 90 percent of the time and the other 10 he's about a sec or less behind - I believe he may have been using the LCD - not 100% but the peaking is useful for general reference but if you're unsure, a bit more practice with the 35mm adapters and some trial and error and I think you'll be pretty happy with the results. Peaking is helpful but I'm not betting the farm on it -

mike
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Old October 25th, 2007, 09:29 PM   #8
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Thanks Michael, you saved me a lengthy post. I concur with everything you said.

The soccer footage you mentioned was without a follow focus or external monitor and was done with peaking on the LCD. Keep in mind, however, that I was using a 200mm lens so the depth of field was relatively shallow, making it a little easier to focus. No such luxury exists with 28mm and wider lenses because of the dramatically increased depth of field.
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Old October 25th, 2007, 10:36 PM   #9
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hi steven sorry to bother you in here but was reading this post and saw that the soccer match was with 200mm lense and letus extreme just curious does that mean that if i zoom all the way on the camera that is 20x and if i have same setup as yours with letus and 200mm lense i still get another 200mm on top of the 20x zoom ??
am inquiring regarding my trip next year to africa and want to get all the info i can get of you guys have been following your posts and have learned a lot but still me being ignorant to most things am trying to keep it up with most what is said.....sorry again if this is very basic
thanks for your response in advance
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Old October 26th, 2007, 05:17 AM   #10
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Michael,

Thank you for the spot on reply. You understood my questions perfectly.

I have a Dell 2407WFPHC (1920x1200) and was wondering if using it would be the way to go (at least initially). Since I have access to power for most of my shoots I see this as a viable option.

I connect the A1 via the component cable to the monitor. The picture is good but a bit grainy. I believe a down conversion takes place when using the component out?

Steven, Thanks for seconding Michaels reply. By the way, how do you turn on peaking/zebra etc. on the monitor?
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Old October 26th, 2007, 05:37 AM   #11
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News to me that you can turn on peaking on the ext monitor? Have a missed a custom config setting?

-EDIT: Just remembered that Stephen uses a Marshall, is it SDI or Component connected? Maybe those output with peaking but composite doesn't?
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Old October 26th, 2007, 09:52 AM   #12
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Kris,

Steven is shooting with an A1 with the Extreme, which is HD component out - I haven't personally looked to set peaking on an external monitor but wouldn't be surprised, last time I went into the Canon A1 menu, there was a setting that would drop my daughter off at school if I enabled it - gotta love Canon :)

Shiv,

The Dell will look a bit grainy. There isn't any downconversion if you're monitoring live to an LCD - you'll see it all but keep in mind you're using an LCD designed for computers, not necessarily for broadcast so again, calibration as best as possible is necessary to insure you're as close as possible to an accurate picture. If you've got the power, use it. It will do the trick.

There's a reason the new JVC / Panasonic / Sony pro LCD's are $5k plus ;)
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Old October 26th, 2007, 09:59 AM   #13
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Michael,

How does one calibrate such a monitor (PC monitor). Is it the same as color calibrating a monitor for Photography work?

Since no PC is involved (while the A1 is connected directly to the Monitor, I don't think the color calibration (which really uses an ICC profile) is effective.

Is the calibration subjective or done using some gadget?

And what's the reason for the $5K plus monitors?
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Old October 26th, 2007, 07:00 PM   #14
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Monitor Calibration

I use a Dell 24" LCD as a preview monitor and calibrate it by outputting color bars from the camera to the screen over component. Once you have the bars on screen, there are several approaches to calibrating. I won't get into them here as there are plenty of existing sites describing the process (probably many posts here on dvinfo as well).

I use my Dell LCD mainly for focusing with my Letus adapter so I'm not super picky about the color so sometimes I just eyeball it for color.
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Old October 27th, 2007, 09:20 AM   #15
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Quote:
Originally Posted by Mickey Mackwan View Post
hi steven sorry to bother you in here but was reading this post and saw that the soccer match was with 200mm lense and letus extreme just curious does that mean that if i zoom all the way on the camera that is 20x and if i have same setup as yours with letus and 200mm lense i still get another 200mm on top of the 20x zoom ??
Did someone answer Mickey's question?

I'm curious about this as well.

Thanks

Rog Lee
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