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-   -   Lens cap for setting the aperture and exposure is finally here (https://www.dvinfo.net/forum/canon-vixia-series-avchd-hdv-camcorders/113981-lens-cap-setting-aperture-exposure-finally-here.html)

Aaron Courtney March 3rd, 2008 04:31 PM

David, great little invention from what I've seen. Couple of questions though: What are your plans for accommodating Canon's wangle and telephoto converters? Also, why not use more light to stop down the lens to say f4 at +-0 so you get a wider range of stops to work with, particularly on the - side (perhaps reaching f8) and therefore, possibly, avoid the necessity of using external ND filters in brightly lit outdoor scenes?

David Delaney March 3rd, 2008 09:39 PM

Aaron,
I have been thinking offering a couple of different diffusers for different lighting situations -
1) for outdoor, a diffuser that would range from 5.6 to 8.0
2) for indoor, a diffuser which runs from 2.0-5.6

In this way, depending on your situation, you could switch them around on the fly or before-hand to get what you want.

Does this sound like a viable option?

Glenn Thomas March 4th, 2008 07:01 AM

Sounds like a great product, and even more so if it can be set for both indoors and outdoors... And just when I finally got around to calibrating the screen of my phone with a big white image! Will see how I go with the phone, and whether or it remains consistent. If not, I may have to order one of these from you.

Aaron Courtney March 4th, 2008 02:07 PM

David, I gather from your reply that we can't get a +11 to -11 exposure scale. I don't have the HV20 so I obviously can't determine this for myself. But I do have the HG10 and they should function identically in this area. I have not been able to get a complete +11 to -11 scale after locking exposure.

David Delaney March 4th, 2008 05:08 PM

Yes I can get the -11 through +11 at 4.8 aperture rating. Not a problem at all if that is what you are asking. The main problem is the image is quite dark unless you have a lot of light.

Aaron Courtney March 4th, 2008 11:57 PM

Well if +-0 is 4.8, then what is +11 and what is -11? The whole point of this should be to get as wide of an aperture range as possible with zero gain. This is kinda what Steve Witt was getting at. Give us the widest aperture range with zero gain. You can't do that if you center the scale at 2.8 because your -11 only stops down the lens to what, f5.6? I'm looking for f8 on the - side and f1.8 on the + side...so the whole aperture range @ 1/48 with zero gain.

David Delaney March 6th, 2008 08:13 PM

Did you see this :
http://lytecap.blogspot.com/2008/02/...g-lytecap.html
Is this what you are referring to?

Aaron Courtney March 6th, 2008 10:32 PM

Hey David, no I didn't see that, but it sounds a lot like what I'm talking about here. I'm not sure why anyone would want to limit the scale by centering around f2.8. You'll never be able to stop down to f8.

So my question is exactly which aperture at neutral gives the widest array of f stops with zero gain @ 1/48 shutter speed? And what are the exact #'s at -11 and +11?

David Delaney March 6th, 2008 10:41 PM

I understand what you are saying.
Here is the way I look at it - if you are shooting outdoors, you are going to have a different aperture set then indoors - easy to understand. But if you look at the pictures on my blog in comparison, when I cranked up the EV to +11 at 4.8 aperture, there isn't much light being let in. When you set the aperture at numbers like 4.8-5.6, it really is dark even when you turn up the EV notches to the highest number. This aperture rating would be perfect for outdoor use because you don't want to blow out the image anyway unless you have some ND filters.
I think finding the right number is key, but so far, even though I can't get the fullest range from 2.8, I enjoy the look and sharpness of the image (I compared the images at two different apertures on my blog).
I am going to have to sit down and run through all of the apertures and see what results I get - hopefully during March Break.

Aaron Courtney March 7th, 2008 08:54 AM

Quote:

Originally Posted by David Delaney (Post 838600)
But if you look at the pictures on my blog in comparison, when I cranked up the EV to +11 at 4.8 aperture, there isn't much light being let in.

Well, that's what you would expect when comparing f4.8 to f2.8 - less light because you're stopping down the lens. Or are you saying that f4.8 @ +11 is not as bright as f4.8 @+-0? Or f2.8 @ +11 is not as bright as f2.8 @ +-0?

If everything is kosher here, then it shouldn't matter where you are on the sliding scale. F2.8 @ +11 should yield identical results as f2.8 @+6, +-0, and -6 (as long as the shutter is locked at 1/48 and no gain on any setting). How are you determining whether or not the HV20 is adding gain when you're experimenting like this?

Aaron Courtney March 7th, 2008 09:03 AM

Quote:

Originally Posted by David Delaney (Post 838600)
Here is the way I look at it - if you are shooting outdoors, you are going to have a different aperture set then indoors - easy to understand.

Not really. IMO, this entire process should be treated exactly as you treat exposure with film. You have a lens with a fixed aperture range and that's all ya got. If you're going full manual with this device, then everyone should desire the widest aperture range. If f8 is still not enough for outdoor work, then add an ND filter.

As long as, for example, f2.8, 1/48, 0 gain yields the exact same exposure whether that setting is found @-6, 0, +6, or +11 ticks on the scale, then I can't see why anyone would want different scales for indoor vs. outdoor work.

Joseph H. Moore May 25th, 2008 03:07 PM

What's the status on the 35mm adapter version?

Edward Grabczewski September 23rd, 2008 05:59 AM

Try using the LIGHT
 
You can save yourself some money by simply pointing the camera about six inches from a white sheet of paper and switching on the LIGHT. The amount of light emitted will set your maximum aperture to around 2.0.

By increasing the distance then the max aperture will increase to 1.8 and by descreasing it then it will decrease slightly.

Cheers

Eddy Grabczewski

The Sound Manifesto Website


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