EX3 Relay for Letus adaptors

Here are some comparison stills using a old 35mm nikon f1.4. This also shows crop factor with ex3 letus and stock lens zoomed into z74.

EX3 is wide open with 1/100th shutter in.
EX3 Letus Ultimate and stock lens is wide open on both ex3 and 35mm lens
EX3 Relay and ultimate stopped down on relay by 2 stops.
 

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Philip,

Thanks for posting those grabs. Yes, the naked lens is a whole different world. The relay image is down a tiny bit on exposure compared to the stock lens/Ultimate, FOV is different and DOF seems a bit shallower. Sharpness seems similar, focus point is a bit different(bottle on left sharper on stock/Ultimate, bottle on right sharper on relay/Ultimate), contrast looks similar--both shots with Ultimate have less contrast than naked lens.

It seems, by looking at these image via the net, that the speed is the most obvious factor for using the relay. Closing down to F2 on relay and taking lens didn't seem to affect contrast positively. The relay grab looks a bit colder.
 
Dino said:
Philip,

Thanks for posting those grabs. Yes, the naked lens is a whole different world. The relay image is down a tiny bit on exposure compared to the stock lens/Ultimate, FOV is different and DOF seems a bit shallower. Sharpness seems similar, focus point is a bit different(bottle on left sharper on stock/Ultimate, bottle on right sharper on relay/Ultimate), contrast looks similar--both shots with Ultimate have less contrast than naked lens.

It seems, by looking at these image via the net, that the speed is the most obvious factor for using the relay. Closing down to F2 on relay and taking lens didn't seem to affect contrast positively.
Click to expand...

yep, the frame of view is different, slight change of height with different rigs but mainly because relay is academy frame whilst the stock lens with ultimate is a tad wider when at z74...its all so tricky to make this scientific without three identical cameras, two identical slr lenses and two ultimate all rolling at same time, taking each bit off and then matching is quite a task. Relay is a tad under compared to the stock lens ultimate but just a tad...it still looks like a good 2 stops which is terrific news for people like me who like subtle natural lighting.

Sharpness edge to edge is superb, but you need Mr. Stunzi and co with their charts to check that. I can print one out but all i can do it on is a4 paper, so not ideal!
 
Philip,

I really appreciate your doing all this--I know it is time consuming and not very creative. I do believe that for those who do a lot of indoor shooting, and like you, want a natural, available light look, the fast relay difference is BIG. As I've stated previously, many look at their stock camera lens, see "f1.8" and think that is what they'll be shooting at when zoomed in to Z74 or whatever when using an adapter.

If you're getting close to two full stops more sensitivity with the relay lens vs. stock, that's a stock zoom lens ramping effect of somewhere around f2.4-2.8. vs. the f1.8 many think they're getting. Does that sound accurate to you? An f1.5 relay is really brilliant, albeit expensive!
 
yep what i did was put letus on ex3 stock lens. Zoom in, have stock lens wide open and stop down on 35mm lens to get correct exposure.

I then put relay on with ultimate, had relay wide open and had to stop down just over 2 stops more on 35mm lens to get correct exposure...best way I could think of measuring it. Unless you can think of a better way?

The frame grabs you see aren't the ones from the measuring, the 35mm lens is wide open at f1.4 and the stock lens/ relay iris/ shutter is used to maintain DOF whilst keeping correct exposure.

I think I need to go to bed soon. Got to do more SGBlade tests tomorrow and take EX3 / relay for fun shoot in the big smoke!
 
Philip,

I think that works fine for seeing exposure difference.

Will you have a chance to stop way down with the SGBlade on an exterior with sky tomorrow? Also, high shutter speed tests? The Ultimate does the former quite well, but not the latter, in my experience 1/500th is pushing it, before some GG streaking effect becomes obvious on a flat field.
 
Don't forget field flatness as a positive. It looks a lot flatter at the edges. And, in my own HPX3000 testing I noticed that this was true A) Wide open and B) With a really Crappy 17-35mm lens!

So the positives of a relay on cameras with removable lens options are both Speed and Field Flatness or Edge to Edge image quality.

It also does a bit of a job on the Bokeh, but I'm no bokeh whore myself. If people are paying attention to your background (when they aren't supposed to be) then there's an issue.
 
yeah it does look flatter. It's a marvelous piece of kit.

I probably will do the Blade testing Sunday as think have bitten off more than I can chew, especially as am working every day next week so don't want to kill myself!

I will try some high speed shutter on the Blade, just depends if there will be enough light or not in out grey capital city!
 
Yes, uniformity edge to edge focus and contrast wise is something a well designed relay should offer, but the EX1/3 with stock lens and Ultimate is pretty good already. It looks better than my Fujinon HA18X7.6 2/3" HD zoom in the corners.

A relay lens is a necessity for 2/3" cameras, but is obviously useful for 1/2" and 1/3" camera with detachable lenses.
 
Here is a screen grab of Mark Dawson of LondonMarkFilms.com from my EX3/relay/ ultimate short i made today
 

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Philip,

Your grading/plugins gave this piece a more contrasty look, color in the blacks, mid-range compared to the original piece--this, in conjunction with the music, made it feel like an early '70's 16mm short(except for the 35mm DOF).

The optics looked good, edge to edge and lack of CA were good. The Letus relay didn't seem to be causing any optical issues, more likely letting the personality of the 35mm lenses come through without stock zoom lens adding anything.
 
As I said in the past the reason that forced me to make a relay was for my company's rental... so I look at all these advances with great interest... on the other hand by trying to test and measure my lenses I learned a lot... So now I'm observing things deeper...

In the short the last two time lapses have soft edges and CA... but I thing they are coming from the front lens and I'm 90% sure... In the SGblade thread everyone immediately notice it but then it was blade... in the Letus relay I don't thing that the footage, being out, has any CA or edge softness but on the other hand I don't know the aperture in the relay when that footage was shoot... and that is a very critical subject... all daylight shoots have to have at least two to four stops down either the front lens or the relay in order to have correct exposure... I want to know if there where ND's to do that...

Or better Philip can you document in a next short the ND's, the relay aperture, front lens type and aperture in your shoots, in order to be able to have a better understanding of what is going on...

You see we know that you are a very good DoP and director/editor so whatever you shoot it will look good especially with good grading...

Please help me to understand If I want to buy a relay that really has F1.5 top performance or not...
 
You're right, Evangelos. Wide open performance is very very important and critical, it should be added. That's why you should use the best glass you can afford and grab the best adapter system you can in hopes to minimize the negative anomalies.

I posted up some wide open shots here: http://www.dvxuser.com/V6/showpost.php?p=1557744&postcount=113

The first one is at 17mm with a very poor 17-35mm lens. All wide open.

The rest are Zeiss Contax primes.
 
Kholi, as the relay is the academy frame, the crop factor is around 50% correct? So you would not even see the edges of the SLR 36x24mm image to start with? It's a question...I'm not taking the piss!

I'm still stuck on the fact that a 17mm will become around a 32mm...and that's as wide as you'll get.



Kholi said:
You're right, Evangelos. Wide open performance is very very important and critical, it should be added. That's why you should use the best glass you can afford and grab the best adapter system you can in hopes to minimize the negative anomalies.

I posted up some wide open shots here: http://www.dvxuser.com/V6/showpost.php?p=1557744&postcount=113

The first one is at 17mm with a very poor 17-35mm lens. All wide open.

The rest are Zeiss Contax primes.
Click to expand...
 
cd_albert said:
Kholi, as the relay is the academy frame, the crop factor is around 50% correct? So you would not even see the edges of the SLR 36x24mm image to start with? It's a question...I'm not taking the piss!

I'm still stuck on the fact that a 17mm will become around a 32mm...and that's as wide as you'll get.
Click to expand...

Just hold your horses for a while. I'm sure there'll be a good solution for you down the road. If you don't like the Letus relay, look at the Cinevate relay that zooms.

This thread was originally about the EX-3 relay. These adapters already work fine with the 1/2" sensor of the EX series... the relay just helps to improve the overall performance... and reduces light loss.

They're aimed at professionals... and I urge everyone to keep that in mind.

Also be specific! A 17mm cinema lens will have the FOV of a 17mm lens. A 17mm SLR lens... will be cropped. There's a difference here. One thing that sucks is how the RED market has dried up all the good used 35mm PL lenses out there. Otherwise, we'd all be good as gold with nice cinema quality lenses with academy framing!
 
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