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Thread: Easy Testing Used LF Lenses?

  1. #1
    Tin Can's Avatar
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    Easy Testing Used LF Lenses?

    Yesterday I posted 2 unsharp 5X7 neg scans Here

    My question is, how can we quickly test a used lens for sharpness?

    I may not be able to literally see the problem, with my vision on a GG, even with a 9X loupe

    I was and am aware of how unsharp the 2 images are. I processed both with 4 other 5X7 negs shot with a SF lens. Those cannot be posted. They are far sharper.

    As I 'see' it, 3 primary variables are GG T, alignment of standards and the lens

    All my lenses are second hand 'bargains' some bought here but most from a 1960's estate

    Not trying to assign blame

    A thought and caution to others, it was common for Pros to test any lens with a few iterations and return the chaff

    Buy beware
    sin eater

  2. #2

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    Re: Easy Testing Used LF Lenses?

    For every lens I have acquired I do an initial simple lens test of the same scene. Location 1 with the factory buildings if the weather is nice, location 2 of the center of our town when the weather is not so nice... taken from an elevated porch with a roof over my head and shielded from the wind. Always focus on the sign in one location and the stop sign in the other. Usually shoot at f/32. Both scenes include signs or license plates or other objects that practically allow me to judge the sharpness of the lens. Both locations are within a 2 minute drive from my house. From unpacking a lens, to leaving my house, to hanging up a negative to dry takes way less than an hour. When the negatives are dry, I mark the film edge with the lens used, f/stop, date taken, and other notes. This just simply works for me.
    Attached Thumbnails Attached Thumbnails location1.jpg   location2.jpg  

  3. #3

    Re: Easy Testing Used LF Lenses?

    First 5x7 Norma Test 75f8 SA CF E3 150F9 Aristo2 Perfection 3.5min by Nokton48, on Flickr

    When I was young I generally followed Fred Picker's advice, as well as Gordon Hutchings.

    Tree branches make good resolution targets. This is a Sinar Norma 75mm F8 Super Angulon barrel/rabbit ears with matching Schneider Center Filter (marked Center Filter for 75mm F8 SA).
    5x7" Norma

    Obviously I was interested in the outer edges of the circle. Used to use a lot of extreme rise all the time. NP with Norma superiority!

    Also test of Omega E3 with Omegalite and glass carrier.
    Last edited by Daniel Unkefer; 4-Dec-2019 at 10:04.
    “The secret of getting ahead is getting started.”
    ― Mark Twain

  4. #4

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    Re: Easy Testing Used LF Lenses?

    Quote Originally Posted by Tin Can View Post
    Yesterday I posted 2 unsharp 5X7 neg scans Here

    My question is, how can we quickly test a used lens for sharpness?

    I may not be able to literally see the problem, with my vision on a GG, even with a 9X loupe

    I was and am aware of how unsharp the 2 images are. I processed both with 4 other 5X7 negs shot with a SF lens. Those cannot be posted. They are far sharper.

    As I 'see' it, 3 primary variables are GG T, alignment of standards and the lens

    All my lenses are second hand 'bargains' some bought here but most from a 1960's estate

    Not trying to assign blame

    A thought and caution to others, it was common for Pros to test any lens with a few iterations and return the chaff

    Buy beware
    What lens, aperture and dev did you use?

  5. #5

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    Re: Easy Testing Used LF Lenses?

    Quote Originally Posted by Tin Can View Post
    Yesterday I posted 2 unsharp 5X7 neg scans Here

    My question is, how can we quickly test a used lens for sharpness?...A thought and caution to others, it was common for Pros to test any lens with a few iterations and return the chaff

    Buy beware
    What kind of motion blur did the concussion of a fired canon give? How stable was the tripod, and how far from the muzzle blast?

    Just rhetorical questions.

  6. #6

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    Re: Easy Testing Used LF Lenses?

    Quote Originally Posted by Daniel Unkefer View Post
    First 5x7 Norma Test 75f8 SA CF E3 150F9 Aristo2 Perfection 3.5min by Nokton48, on Flickr

    When I was young I generally followed Fred Picker's advice, as well as Gordon Hutchings.

    Tree branches make good resolution targets. This is a Sinar Norma 75mm F8 Super Angulon barrel/rabbit ears with matching Schneider Center Filter (marked Center Filter for 75mm F8 SA).
    5x7" Norma

    Obviously I was interested in the outer edges of the circle. Used to use a lot of extreme rise all the time. NP with Norma superiority!

    Also test of Omega E3 with Omegalite and glass carrier.
    I've always relied on name brand lenses to ensure sharpness, Schneider, Nikon, Rodenstock and Fuji.

    I like Picker's advice. It provides a means to check the sharpness of a lens.

    But, I can't help thinking that sharpness is overrated. There are so many other attributes that contribute to a good photograph, like composition, tonality, highlight and shadow rendition, print color, etc. By sticking to name brands and lens formulae, I tend to assume that lenses will be sharp. But, you sure can't assume these other attributes. They really take effort to achieve.

    To be fair though, I tend to print on 8x10 paper. If I printed larger, I might take sharpness more seriously. I think that lack of sharpness can detract from an image. But, does it really ever contribute to an image?

  7. #7
    Mark Sawyer's Avatar
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    Re: Easy Testing Used LF Lenses?

    Personally, I'd shoot a paper negative.
    "I love my Verito lens, but I always have to sharpen everything in Photoshop..."

  8. #8
    Tin Can's Avatar
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    Re: Easy Testing Used LF Lenses?

    Thanks for all the replies. I am going to find or setup a repeatable target and reshoot this lens and film in the next few days. 2 ways, GG as is and reversed. Also fresher film.

    Lens is Calter IIE 150mm f6.3 like new. I have shot this lens on 4X5 with good results. The camera in LN condition, Premo SR 5X7 with no light leaks. But it did come with a smashed GG which I replaced with DIY. My DIY GG work fine on other cameras. But I think I have seen this type camera with GG ground and focus side installed away from the lens. T is impossible to measure due to the way the camera is assembled with internal GG. Getting at it from the lens side is also tough.

    The image was shot at f22 1/30th cloudy shade. Metered 200 iso, heavy tripod. Tri X 320 processed by gas burst Rodinol 1/50 14 min 70 F per Mass Dev. HP5 from same dunk looks good too.

    Focus was the wheel spokes.

    Garrett, I didn't notice recoil, but maybe. No round loaded, I think he said 1lb powder and normal was 10 lb powder with load. I may be wrong. The powder was a palm of his hand small bag. Distance to cannon perhaps 30 ft.

    The film was poorly stored, I have 3 more holders of it, They were all loaded 3 years ago, put in non conditioned storage and recently brought in house.

    Yet other film from the same conditions seems fine and all processed negs look fine.

    Video of a similar cannon and recoil. https://youtu.be/EL13quhcUMw This definitely did not occur. It was loud, the girl very nervous and shaky.

    The setup neg is similar...
    sin eater

  9. #9

    Re: Easy Testing Used LF Lenses?

    Years ago I made resolution tests of all of my lenses using a resolution chart. It was an interesting practice, and prompted me to get rid of a few lenses which did not perform very well. It also prompted me to think about aperture in a different way than I had been before, and now try to shoot at f11 or f16 whenever possible. I don't bother any longer doing a formal test, but take a picture of my backyard at f8 and make sure the little branches are still sharp.

  10. #10

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    Re: Easy Testing Used LF Lenses?

    Quote Originally Posted by Tin Can View Post
    ...

    Garrett, I didn't notice recoil, but maybe. No round loaded, I think he said 1lb powder and normal was 10 lb powder with load. I may be wrong. The powder was a palm of his hand small bag. Distance to cannon perhaps 30 ft.

    The film was poorly stored, I have 3 more holders of it, They were all loaded 3 years ago, put in non conditioned storage and recently brought in house.

    Yet other film from the same conditions seems fine and all processed negs look fine.

    Video of a similar cannon and recoil. https://youtu.be/EL13quhcUMw This definitely did not occur. It was loud, the girl very nervous and shaky.

    The setup neg is similar...
    Let me clarify: the blast, (sonic concussion) from a canon going off is enough to rattle a camera. You'll see it at times in the video you posted, everything shakes as it passes the camera, even on a tripod. So depending on when you tripped the shutter on the "not sharp" shot (which looks to me milliseconds after the gun fired) you could have gotten some camera shake - an less sharp image. It also matters if you are behind the gun, or to the side of it (much more muzzle blast).

    Taking a photo when the concussion hits makes a less sharp photo. The next shot slightly before or after makes a sharper photo.

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