Just Got my Letus35 FE

[Shiv Kumar]

This is exciting! All these new toys...

I managed to get it all assembled and working, whew! But I have some nagging questions.

Essentially, I'm wondering How I set up the focus, such that the camera is focused on the ground glass of the letus. I find there are many ways to achieve focus. That is even though things appear ok, it's possible that you're loosing the "range" (minimum focus distance to infinity), Or something.

I'm finding it hard to explain what's nagging me since I don't have the vocabulary down yet.

So It's appreciate it if people using a Letus with the A1 would respond. I just want to make sure I'm doing it right.

Exposure:
It seems to me, that what the camera shows as correct exposure is actually under exposed. Is that just the 35mm look or because the letus is dropping 1/2 f stops that I should be over exposing by that amount?

I've got my zebra set to 100 IRE. With some reflective objects in the frame I don't get zebras on them untill I go 2 stops over exposed.

FYI: I'm using a Nikon 50mm f/1.4 SLR lense.

Any help, suggestions etc. would be appreciated. I've got my first shoot comming up first thing next week and I'd like to get it right and practice with the Letus before that.

Shiv.

[Shiv Kumar]

Another question I have is about zooming.

Since I'm using a 50mm lens:
Once I've set the zoom on the camera to what it should be. I use the zoom set feature on the camera. Now I can actually zoom in and using the zoom set feature pull back to the "normal" zoom position. It all looks pretty good.

My question is, is there any harm (quality wise etc.) if I were to shoot using this kind of zoom in cases where I need to zoom in in order to frame my shot correctly? Or should I avoid this and rely on moving the camera and/or subject to get the correct framing?

[Steven Dempsey]

Originally Posted by Shiv Kumar

Essentially, I'm wondering How I set up the focus, such that the camera is focused on the ground glass of the letus. I find there are many ways to achieve focus. That is even though things appear ok, it's possible that you're loosing the "range" (minimum focus distance to infinity), Or something.

You have to forget about the lens on your XHA1 when you are using an adapter. Once you have zoomed in to the picture on the ground glass enough so you have no vignetting, then you are getting close to the full focal length of the lens you have attached to the Letus. You don't need to worry about where your zoom is on the camera itself. So get that out of your head.

Originally Posted by Shiv Kumar

Exposure:
It seems to me, that what the camera shows as correct exposure is actually under exposed. Is that just the 35mm look or because the letus is dropping 1/2 f stops that I should be over exposing by that amount?

I've got my zebra set to 100 IRE. With some reflective objects in the frame I don't get zebras on them untill I go 2 stops over exposed.

FYI: I'm using a Nikon 50mm f/1.4 SLR lense.

I'm not sure why this is happening. Are you sure that the monitor you are watching your footage with is properly calibrated and the brightness/contrast settings are correct? Using the zebras to judge exposure blowouts should work, if it doesn't, take the zebra level down to something that does work like maybe 90. The Letus doesn't really suffer from any major hotspots. While you are shooting some test scenes, talk into the microphone and say what adjustments you are making. That way, when you capture the footage, you can see what changes are taking place based on various zebra settings. Find the one that works for you and leave it set to that.

[Steven Dempsey]

Originally Posted by Shiv Kumar

Another question I have is about zooming.

Since I'm using a 50mm lens:
Once I've set the zoom on the camera to what it should be. I use the zoom set feature on the camera. Now I can actually zoom in and using the zoom set feature pull back to the "normal" zoom position. It all looks pretty good.

My question is, is there any harm (quality wise etc.) if I were to shoot using this kind of zoom in cases where I need to zoom in in order to frame my shot correctly? Or should I avoid this and rely on moving the camera and/or subject to get the correct framing?

You really have to look at this setup the way you would a film camera with a prime lens. Move the camera to frame your shot and if that doesn't do it, try a lens with a longer or shorter focal length. Zooming in will not do any "harm" per se, but you will begin to lose sharpness as you zoom in more because you are essentially magnifying the ground glass and it's not optimal.

Another thing regarding setting an accurate focus for the adapter is to plug your camera directly into an HD monitor and focus on a distant object. When it snaps into focus, set that on the Canon.

If you don't have access to an HD monitor, point the camera (with the Letus attached) to a bright light source with the motor turned off. Make sure the light is pretty even (like the sky, for instance). Focus the XHA1 until you can see all the grains on the ground glass and you are set. Try to make sure that you are not completely over exposed first so that the grains will be clearly visible.

[Shiv Kumar]

Steven,

Thank you for your replies.

FYI:
I don't have a calibrated monitor or HDV Monitor so I'm relying completely on the monitor on the camera.

On the focus issue:
I (by fluke) figure out that if I looked closely, I could in fact see the grains of the ground glass by zooming the camera in fully and fiddling with the focus on the camera. The camera was pointed at a regular floor lamp with a white background. That probably made it easier to see the grains of the ground glass. I thought it was the grains of the wall at first :). Oh yes, the batteries I intend to use for the vibrator were being charged and I figured, it's not dirty yet so. I guess I was lucky :)

I get the "should not zoom part". Not that I have any experience with film cameras. But during one of the experiments, I found while zoomed in, I couldn't really get a sharp focus (or the DOF was so shallow that it was really impossible to focus). So I guess that's a good reason not to use it. Thanks for that point.

I've bought a 105mm f/1.8 that is being shipped directly to my customer's office and so I should get it when I get there. So if I need I choice of lens I'll have these two. I did try a few framing experiments this evening and I think I could use the 50mm (it's just that the camera is literally in the talent's face (about 3.5-4 feet).

but you will begin to lose sharpness as you zoom in more because you are essentially magnifying the ground glass and it's not optimal.

So what's the reason for using gound glass? I guess you need a "screen" to project on so the camera can feed off of it huh?

Are you sure that the monitor you are watching your footage with is properly calibrated and the brightness/contrast settings are correct? Using the zebras to judge exposure blowouts should work, if it doesn't, take the zebra level down to something that does work like maybe 90.

So you're saying that technically the camera's exposure meter is still reliable correct? I'll play around some more.

talk into the microphone and say what adjustments you are making.

That's a really brilliant idea! I didn't think about that.

You have to forget about the lens on your XHA1 when you are using an adapter.

Yes, I learnt about it here in these forums. But it's not quite that simple. The number of times I've touched the focus or zoom...It takes a bit of concentration or habit. The SLR lens' focus ring is quite a reach from behind the camera too :).

Now all I need to do is shoot like you :). Don't know if you got my email. I bought you DVD and I'm looking forward to seeing it a learning it.

Thanks for your time and help.

Shiv.

[David Chia]

Originally Posted by Shiv Kumar

Yes, I learnt about it here in these forums. But it's not quite that simple. The number of times I've touched the focus or zoom...It takes a bit of concentration or habit. The SLR lens' focus ring is quite a reach from behind the camera too :).

Shiv.

Just use the preset ( zoom / focus) function on the XHA1. set it up once you get it on the G.G and when you accidentally move the focus or zoom on the XHA1 , just switch the "on" button and it will go back it original settings (depending on which one you mess up).

[Shiv Kumar]

David,

I've actully been using the preset focus for this. For some reason I thought it was one or the other (zoom of focus). Thanks for letting me know!

The other issue is the fact that the Letus doesn't or can't fit tight on the camera since (at least the way I've done it) you have to unscrew it a bit to get it perfectly horizontal.

So now, a little touch can shift it from its desired position. Anyone have a solution for this?

[John L. Miller]

The aluminum threaded ring on the Letus that screws into your camera will turn inside the letus housing. It is NOT glued, it just fits snugly into the housing. It is not glued so you can turn it. Mine got tight before it was aligned properly, so I just kept turning it once it got tight to the camera, it turned inside the housing of the letus. Once I got it where I wanted, I marked it a sharpie and I plan to take the threaded ring out and shim it with paper or permanently glue it, I hate to make it permanent though, you may want to remove it sometime in the future. In short, screw your letus into your camera until tight. I recommend you use a clear dual threaded filter in between the letus and the camera so you do not scratch the lens, I speak from experience. Once your letus it tightly screwed into your camera, you can grab the housing of the letus and twist it counter clockwise and pull and it should slip off the aluminum ring. Then you can align it however you like and press it back on. It worked fine for me. Hope this helps. John

[Shiv Kumar]

John,

Thank you for your post. I do you a filter on the camera (I think I got that from reading one of your other posts about scratching your lens).

At one point, the filter got so tight I couldn't unscrew it off of the camera. I eventually resorted to using a lot of strength to get the filter unscrewed (it got over tight due to mounting the Letus).

I've not pulled the Letus off the aluminum mount (yet) but it's now at a point where, when the Letus is reasonably tight on the filter, it's almost perfectly aligned.

[John L. Miller]

no problem shiv, glad everything is working out good for you. J