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Lens Shading for the 85/1.2

Gentlemen, please stop getting personal about this subject. Information is shared, opinions are stated, others can take what they wish and use it or not.

I, for one, use the 85/1.2 with a 77 to 82 ring and #4 hood. I've seen a very slight vignetting in the corners on a few occasions ...
but it has to be a very flat, even tone being shot. In reality, it is a non-issue for 95% of photography. Manufactures always error on the side of being conservative.

If it is a critical issue for some photographers, then a different hood system should be sought out. For ex&le, the Lee system
has adapter rings for all these lenses, and much more effective baffled shades. There are similar systems made specifically for 35mm lenses which aren't as bulky, but also offer baffled shades.

As usual, it comes down to convenience verses effectiveness.
 
yeap, bellow hoods are the best....

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How about these "hoods" ?

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The bigger lens is 85 1.2 60yr, the cardpaper cutting reduces the area of light entering to half of the original area. 85 1.2 becomes 1.7.
The smaller lens is 85 1.4 being converted to 85 2.

I have been playing with these tricks for a while. For 85 1.2, I don't find these occlusive hoods very useful. However, 85 1.4 becomes a very useful lens. The occlusion makes the lens a lot more useable at f2, better than the f2 made by rotating the aperture ring.

These 'hoods" does not vignette at corners, at least in practice. This is why I found it difficult to believe that hood 5 causes darkening of corners. These two lenses, after occlusion, still has the entrance bigger than the lens 85 2.8. So,if 85 2.8 does not vignette, these occluded lenses won't.

If you try this on 85 1.4, it might make the lens so good that you may think 85 1.2 is less indispensible.

By the way, about the question of me spending less than 2 k on a mint 85 1.2. People may think Hong Kong has an endless supply of these expensive lenses.

On that day, the guy selling the lens did not aware how much he could sell the lens in e-bay. He sold the lens in very low price to the shopkeeper. It happens that I was watching them in the shop. If I came to the shop latter not seeing them, the shopkeeper would increase the price to a lot more than 2k.
I brought these lenses in such a low price only because of pure luck. Unfortunately, luck does not come everyday.
 
So a piece of cut-out cardboard on top of the 85 1.4 improves the image - who would've thunk?

Chi Yuan, what kinds of image improvements are you finding at f2? Do they carry over to the smaller openings?
 
Instead of me posting results, please try it yourself.

The principle of cardboard cutting on 85 1.4 is as follow.

The f2 of 85 1.4 obtained by rotating the aperture ring to f2 is not good enough. Light passes thro' all part of front elements followed by squeezing thro' the aperture. Most aberration occurs at the peripheral part of the front lens elements. The front element is the biggest and marginal aberration do occur badly.

The cardboard cutting ensures light passes only thro' the central part of the front lens elements avoiding marginal aberration of the front elements. It is just like a second aperture infront of the lens.

To me the improvement is such that in the past, I feels sleepy with f2 of my 85 1.4., now the cardboard f2 is comparable to the f2 of 100 f2.

The improvements do carry over to the smaller openings.
 
Here is an ex&le of photo taken by the Planar 85 1.4 at f2, subject 1 meter from the camera. I scan the neg. to more than 6 million pixels, then photoshop. The film I used is Kodah 100 Gold.

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The second image is taken in similar lighting but I put a second aperture in front of the 85 1.4 so that 50% of the light is being stopped from entering the lens, leaving the remaining 50 % entering the lens at the central part. It effectively converts the lens to 85 f2. So the second image is taken at f2 with cardboard cutting second aperture when the aperture ring remains at f1.4.

The second image is slightly sharper, the eyebrow is defined better.
 
The third s&le is taken with the 85 1.4 at 2.8

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The forth s&le is taken with 85 1.4 with the card cutting(as the second aperture in front) and aperture ring at f2. The overall effect is having a lens at f2.8. It is quite clear to me that the forth one is better than the third in terms of the lens sharpness and contrast.
(the transverse lines in the third s&le are artefacts)
 
I have to mention that the film I used for the first and second are Kodak gold 100, for the third,forth and the rest, I used Kodak HD200.

The fifth is taken by 85 1.4 at f4.

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The sixth is taken by the lens with the card cutting and aperture ring at f2.8,making the effective fno. f4.

To me the sixth is slightly better defined than the fifth.

In conclusion, I have preliminary evidence to suggest the cardboard cutting do improve the performance of 85 1.4 at f2, f2.8 and f4, with results most noticable at f2 and f2.8.
 
So, DJ, this is the kind of image improvement I meant at f2 and it does carry to the smaller openings.

In 85 1.4,the diameter of the area which allows light to go in is about 60mm, the diameter of the inner circle of card cutting is about 42mm.

85 1.4, even with this kind of occlusive "hood", does not vignette. I must admit that if 85 1.2 is reduced to 42mm diameter, it will vignette.
 
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