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Andrew Reid

Fast apertures on the GH5 = Full frame

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4 hours ago, tupp said:

No.  The whole point of that apodization demonstration is that the aperture and focal length are EXACTLY identical -- but the DOF is very different.

Then the focus or object distance is not the same.
The APD filter will decrease the apparent aperture and "smooth" it out, and increase DoF somewhat while changing it's character. That is why it's there and what it does. Darkening the edge of the lens is the same thing as stopping it down but smoother. In fact you can do exactly that, stop down by a small amount and take multiple exposures decreasing aperture slightly and then combine them for the the same effect.

 

4 hours ago, tupp said:

By the way, that apodization example originated in this article.

Did you have to grab the one shot he managed to screw up. If you look at the wide open and 1.4 shot you see the bokeh being slightly smaller due to the filter which is 100% expected.

 

4 hours ago, tupp said:

I think that apodization filters are always internal in a lens.  I believe that Fuji had a lens in which different apodization filters could be inserted.

You could put it at front element and at aperture blades. Front element would not work as well if you use it for FF but probably decent enough for 1.5 or 2x crop. The problem would be finding a filter to begin with.

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1 hour ago, no_connection said:

Then the focus or object distance is not the same.
The APD filter will decrease the apparent aperture and "smooth" it out, and increase DoF somewhat while changing it's character. That is why it's there and what it does. Darkening the edge of the lens is the same thing as stopping it down but smoother. In fact you can do exactly that, stop down by a small amount and take multiple exposures decreasing aperture slightly and then combine them for the the same effect.

 

Did you have to grab the one shot he managed to screw up. If you look at the wide open and 1.4 shot you see the bokeh being slightly smaller due to the filter which is 100% expected.

Thanks for the explanation. After reading the previous post I started to wonder if everything I thought I knew about apodizing lenses was wrong, and I started to re-study the subject. Your post corresponds to how I understood apodizers to work.

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4 hours ago, no_connection said:

The APD filter will decrease the apparent aperture and "smooth" it out, and increase DoF somewhat while changing it's character. That is why it's there and what it does. Darkening the edge of the lens is the same thing as stopping it down but smoother. In fact you can do exactly that, stop down by a small amount and take multiple exposures decreasing aperture slightly and then combine them for the the same effect.

If an apodization filter works like an aperture but with a gradated edge,  then I would agree that it decreases the overall apparent aperture (as long as the mechanical iris is larger).

 

However, that gradation of the aperture edge is affecting DOF, and the character of that gradation (combined with the mechanical iris) is one of several variables ignored by the equivalency formula.

 

 

4 hours ago, no_connection said:

Did you have to grab the one shot he managed to screw up. If you look at the wide open and 1.4 shot you see the bokeh being slightly smaller due to the filter which is 100% expected.

Ha!  If he screwed up the focus/distance, then he did so in every comparison except for the f1.4 set and the f5.6 set.

 

In every case except for the 5.6 set, the APD bokeh has a softer edge, as is expected.  In addition, the bokeh progressively gets smaller with each lens as it is stopped down, which is also expected.  On the other hand, the background is softer with the APD filter in every set except for the one at f5.6.

 

So, I am not sure if he screwed up the tests or if such results are peculiar to using a gradated aperture along with a hard-edged aperture.

 

 

4 hours ago, no_connection said:

You could put it at front element and at aperture blades. Front element would not work as well if you use it for FF but probably decent enough for 1.5 or 2x crop. The problem would be finding a filter to begin with.

It sounds like such a filter would easy to make/airbrush.  It's essentially a radial gradation filter.  It could also just be an opaque disk with a large center hole, with progressively smaller holes radiating outward.

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2 hours ago, tupp said:

 

It sounds like such a filter would easy to make/airbrush.  It's essentially a radial gradation filter.  It could also just be an opaque disk with a large center hole, with progressively smaller holes radiating outward.

Wouldn't that cause unnecessary disfractions? Light isn't too fond of moving through small holes. And by opaque I guess you mean an ND filter? An opaque filter in front of your lens would add haze to everything.

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I am forever searching for a 43mm apodization filter.

I have a Fotga adapter for my Canon lenses on my Sony A7s and it has a small space that almost exactly takes the glass from a 43mm filter (I file away the metal rim).

I have used an IR filter successfully (43mm filters are a LOT cheaper than a 150mm one for my 17 TS-E would be and means I only need one size for my Canon EF lenses that fit which is most of them so far).

There are companies that sell individual filters but they are expensive and too small (at least the ones I have found).     There are different sorts too with ones that are reverse.

Would love one of these with a lens like the EF 100 f2 though I have sold that lens but would also love to try it with my Sigma 150 2.8 in EF mount.

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24 minutes ago, noone said:

I am forever searching for a 43mm apodization filter.

DIY: You can create a gradient in photoshop and print it on a translucent paper. Then cut it out and place it as close to the back glass element (closest to the aperture blades). 

Or use this image instead of doing it in Photoshop:

TS940x940.jpeg.28e75162af7c8e98d63895687687fa4a.jpeg

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Thanks, I have seen those before when looking for a filter but while I am trying for a bit of a kludge, I do want a "real" filter with top class glass.

I might just buy the largest I can find and try and use it in APSC mode though it would probably be sticky taped into the adapter.

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8 minutes ago, Robert Collins said:

I dont think a do-it-yourself apodization filter is easy to do. Tony Northrup tried (see 3.16 of the video below) and the results sucked.

 

The examples showed in the link I supplied look great to me. Maybe Tony does suck at doing it.

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17 hours ago, tupp said:

On the other hand, the background is softer with the APD filter in every set except for the one at f5.6.

Softer and size are two different things.

 

17 hours ago, tupp said:

However, that gradation of the aperture edge is affecting DOF, and the character of that gradation (combined with the mechanical iris) is one of several variables ignored by the equivalency formula.

You are grasping at straws. You are looking for a unified theory and are sad when all it does it describe acceleration. You don't need to worry about light speed when all you do is dropping apples. And compare it to other apples.

 

12 hours ago, Don Kotlos said:

print it on a translucent paper.

Problem is it's not exactly optical grade, maybe get some of that meant to print on t-shirt and then transfer by heat, maybe even sprinkle toner on a glass filter and bake it.
We should make a thread bout it somewhere.

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I agree there are better ways than printing a pattern on a paper. Using film is a better way if someone still has access to it :) . You can also use a properly made glass filter like this. At the end of the day,  while nothing will surpass the quality of a lens designed to use an apodization filter like the Sony STF, you can still have some fun trying and you never know, it might result in a usable result like the one found in the linke webrunner posted.

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8 hours ago, no_connection said:

Softer and size are two different things.

Nevertheless, it is a fact that the background is softer with the APD filter in every set of the comparisons that I linked, except for the set with the smallest aperture (f5.6).

 

 

8 hours ago, no_connection said:
On 5/31/2018 at 8:30 AM, tupp said:

However, that gradation of the aperture edge is affecting DOF, and the character of that gradation (combined with the mechanical iris) is one of several variables ignored by the equivalency formula.

You are grasping at straws.

Really?  Please explain how the equivalency formula accounts for the effects of a gradated aperture.  Additionally, please explain how the formula accounts for the combined effects of a gradated aperture and a variable iris separated by some distance within an optical system.

 

 

8 hours ago, no_connection said:

You are looking for a unified theory and are sad when all it does it describe acceleration. You don't need to worry about light speed when all you do is dropping apples. And compare it to other apples.

Huh?  Is this some sort of physics metaphor involving Einstein and Newton?

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3 hours ago, Don Kotlos said:

I agree there are better ways than printing a pattern on a paper. Using film is a better way if someone still has access to it :) . You can also use a properly made glass filter like this. At the end of the day,  while nothing will surpass the quality of a lens designed to use an apodization filter like the Sony STF, you can still have some fun trying and you never know, it might result in a usable result like the one found in the linke webrunner posted.

Thanks, That was one of the sites I had looked at trying to find a 43mm filter to fit my adapters vacant spot.       I forgot they also made a 50mm so maybe I should get one of them sometime and see if I can find another adapter that might hold it.

I came to this by accident as 43mm (thin) filters fit my old 300mm Tamron in lens filter tray and I got a cheap IR filter to put in it.    While looking at my adapters with the IR filter handy, I realised there was a spot in the cheap Fotga adapter about that size but had to file off the rim and it fits great if loose but works.

That got me thinking what other filters might work and the apodization filter was the one I want the most.

The single filters are very expensive for me for what may well be useless but if it works even slightly, that would give me a lot more than just one lens using it (I would love a proper apodization filter lens like the Sony or even the Laowa but beggars can't be choosers).

Maybe I will just try a sandspot filter glass or similar and see what I get with that?

If anyone knows of a company that makes 43mm apodization filters I would love to know.

Any other adapters for canon lenses have spaces that take filters (maybe adapters for the GH5/GH5s to be on topic)?

This was with the 43mm IR filter in the adapter behind the 17mm TS-E

DSC00877.jpg

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On 5/25/2018 at 11:14 PM, Trek of Joy said:

This is not true, and it would be easy to find samples that disprove what you're saying. There is no such thing as the "FF look". 

Chris

Absolutely not true, sorry. Maybe go to film school or somewhere where they can explain this to you.

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On 6/1/2018 at 6:48 PM, tupp said:

Nevertheless, it is a fact that the background is softer with the APD filter in every set of the comparisons that I linked, except for the set with the smallest aperture (f5.6).

Huh?  Is this some sort of physics metaphor involving Einstein and Newton?

Smudging grease on your lens will also make the background softer, but this effect isn't covered by the DOP equivalence formula either.

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2 hours ago, UncleBobsPhotography said:

Smudging grease on your lens will also make the background softer, but this effect isn't covered by the DOP equivalence formula either.

Yes, but smudging grease on your lens will simultaneously make the focused foreground softer, so doing so doesn't really affect DOF as much as it affects the overall focus.

 

On the other hand, an APD filter will not make the focused foreground softer while it does make the bokeh/background softer (than what is expected by the DOF formula).  So, there exist variables other than those in the DOF formula that affect DOF.

 

By the way, never put grease on your lens -- instead, do so on a clear/UV filter.

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