Benefits of Fresnel Lens LED

[tupp]

8 minutes ago, Mark Romero 2 said:

But wouldn't there still be a difference in specular highlights?

Of course.  The larger the source, the larger the specular highlight.  That's why it is best to light flat art and walls with a smaller source -- there's less chance of glare problems because the highlight is smaller.

 

 

11 minutes ago, Mark Romero 2 said:

I know that (in still photography) when a silver-lined umbrella is used, the specular highlights are stronger (more pronounced / more contrasty) than when a white-lined reflective umbrella is used. (And they are even more contrasty when using a non-bounced light.)

A big variable in regards to "harshness" and/or contrast of specular highlights is the distance of the light source from the subject.  The closer the source is to the subject, the greater the subject's diffuse value relative to the highlight value -- so as you move the source closer, the contrast ("harshness") decreases between the highligts and the subject's diffuse brightness.

 

 

14 minutes ago, Mark Romero 2 said:

P.S. Wanted to say thank you again for your input in this conversation. 

Thank you for the kind word!

[Mark Romero 2]

@tupp Merci!!!

[barefoot_dp]

18 hours ago, tupp said:

I can't recall all the times I've seen someone illuminate a diffuser with a Fresnel light, but almost always they focused the light to "full flood" to completely illuminate the diffuser.

Is this simply because the only (or the most convenient) lights they have are fresnels? Or is there some other reason.

  

18 hours ago, tupp said:

A lot depends on what you are trying to do.   I could use that panel fixture naked in a lot of shoots.

Yes, as I said I do use panels as well. But this discussion is about getting equivalent output/quality as a COB keylight with a large softbox - this light can't compete in that respect. Doesn't mean it doesn't have it's purpose.

  

18 hours ago, tupp said:

Softness in lighting is a matter of degree between a point source and completely surrounding your subject with a smooth light source.  There is not definitive "soft light" and "hard light."

Yes, it's all relative. But the original question did quantify what soft light means in this particular discussion - the equivalent of a 4x4 silk or large softbox in very close proximity to a talking subject (so with the exception of some parrots, that would suggest a human-sized subject!).

  

18 hours ago, tupp said:

By the way, you can use a panel light in a soft box.

Yes, as I mentioned you can do that, but not at equivalent prices to most COB lights that I am aware of (any decent 300W LED panels under $500?). If budget wasn't a consideration I'd just get an LS1200D rather that wondering what the most output I can get out of my current lights is!

[tupp]

On 11/13/2021 at 5:36 PM, barefoot_dp said:

Is this simply because the only (or the most convenient) lights they have are fresnels? Or is there some other reason.

The reason diffusion is used on Fresnels is probably a combination of "convenience," bad planning and the fact that most people don't know any better.

Of course, on many sets its a race against time.  Once a light is set up, one generally wants it to live there until it is wrapped.

So, a common practice is to use overpowered Fresnels (which have beam controllability), and then scrim/dim them down to the desired level or, if necessary, use the extra output to bang through diffusion/softbox.  Often there is a piece of 250 diffusion gel rolled up in the Fresnel's scrim box.  This technique often avoids the time sink needed to replace the Fresnel with another fixture, and also having to bring the Fresnel back to the staging area and wrap/head-wrap it.

On the other hand, some folks start out with the intention of using diffusion on Fresnels, even though they may have open-faced lights and softboxes already on stands in the staging area.

 

On 11/13/2021 at 5:36 PM, barefoot_dp said:

Yes, as I said I do use panels as well. But this discussion is about getting equivalent output/quality as a COB keylight with a large softbox - this light can't compete in that respect. Doesn't mean it doesn't have it's purpose.

I am not certain that this thread now has a singular topic, nor am I sure on how an LED panel in a softbox cannot "compete" with any other source with any other source in the same sized softbox.

On the other hand, compared to a smaller light source, the panel light should give a smoother pattern on the front diffuser of a softbox.

At any rate, one could use that panel light in question directly on a middle-aged woman without any complaints from the subject.

 

On 11/13/2021 at 5:36 PM, barefoot_dp said:

Yes, it's all relative.  But the original question did quantify what soft light means in this particular discussion - the equivalent of a 4x4 silk or large softbox in very close proximity to a talking subject (so with the exception of some parrots, that would suggest a human-sized subject!).

I was responding to your statement regarding your "1x1" panels not being large enough for a "soft key."  Your "1-by" is plenty soft for a lot of subjects.

In regards to your original questions, I addressed them here.

 

On 11/13/2021 at 5:36 PM, barefoot_dp said:

Yes, as I mentioned you can do that, but not at equivalent prices to most COB lights that I am aware of (any decent 300W LED panels under $500?). If budget wasn't a consideration I'd just get an LS1200D rather that wondering what the most output I can get out of my current lights is!

Well, now you are bringing up cost, and that is an entirely different consideration.  I have no idea what the prices are for the zillions of LED fixtures out there.

In regards to getting the most output from a "COB" LED source banged through diffusion, it is more efficient to use a reflector on the head and move it close to the diffuser, rather than using a Fresnel (or Fresnel attachment).

[UncleBobsPhotography]

On 11/12/2021 at 12:11 PM, barefoot_dp said:

I'm yet to find an affordable LED panel that offers the same size source/softness as a 4x4 diffusion frame (let alone a larger butterfly!).

LED panels are generally not soft enough by themselves, but an LED panel with a 4x4 diffusion frame will be softer and quieter than a COB/fresnel with the same output.

A COB light which interchangable fresnel and softbox gives you as much flexibility as possible. I've got a couple of COBs/fresnels and a couple of panels and both have their prefered use cases.

It's also worth noting that not all fresnels have the same focusability. Old-school fresnels typically have a larger lens and larger minumin focus area than specialized COB fresnels that can focus very tightly. Some fresnels will also lose more light than others. A bowens mount attachment fresnel might not be as effective as an all-in-one COB and lens since there is more space and the lens has to handle more than one lightsource.