FAQ like Info about 35mm lenses

snodart said:
I was talking with a lens guy at Sammy's camera in LA. He was telling me that older wides (Canon and Nikon) had a spherical element whereas now most wides have an aspherical element. The switch to the aspherical design, so he told me, was to prevent vignetting/hot spots that the older wides caused. Just curious if any of you know anything about this or how to tell if a lens is spherical or aspherical.

I am getting some slight vignetting with a Canon 28mm f/2.8. The vignetting seems to remain the same no matter what size the aperture is (whereas from my various test with adapters... I would expect the vignetting to get worse as the aperture was smaller). I was hoping that trying a few different PCX lenses would correct the problem, but no luck. I wonder if the the spherical shape of the lens is the problem. I suppose I should rent a nice wide and see if I still get the vignetting.
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No idea how to tell the difference man sorry. lol
 
35mm continued

35mm continued

Thank you all for the great information.

I'm shooting a short film in a few weeks and need a package - adapter with variety of lenses - for the DVX-100a... pronto. I've been thinking about the SGPRO or even the MPIC, but I know there are others to consider, also. If I was able to pick up a package with the ones you suggest, TC, 28mm, 50mm and a 150mm or so, I'd be thrilled.

Has anyone seen an adapter with lenses for sale somewhere?

Thanks
 
Great thread! i've been using the M2 with nikon glass, no complaints here. The
Sgpro is nice too.
 
just found this thread, great info! the digital slr issue was mentioned briefly but i was hoping someone could explain this to me, I have a nikon d80 with one of the digital VR zooms, nice lens, has AF/MF etc right on it. If i were to get a brevis lets say, could I get any nikon lenses that would work with both the adapter and the d80 (so i wouldnt have to buy 2 sets), for example a 50mm or a prime 200 or 300mm. from what i understand digital lenses shouldnt be used with a 35mm adapter because theyre made for a digital chip and also they dont have manual apertures? so the only option would be to try find nondigital AF or even MF lenses that would work with the d80 (but its a digital camera, so it only takes dslr lenses or only dslr lenses have all functions enabled?) sorry im confused...
 
Thank you so much for enlightening us with all your experience regarding this. You answered many questions of mine (and many more I probably would have eventually been curious of). This thread will be a great reference for myself and others.

Let me ask a curious question that may have an easy answer. When I first thought of 35 adapters, I was curious about getting a used 16mm Angenioux like the one we used in film school (17-125???). To answer my own question partially I guess this would negate the purpose of trying to get the 35mm DOF. But about the question of backfocus issues, wouldn't a 35mm or 16mm Angenioux or other cinema lens be fine? and why would you advise against using it? unnecessary cost?

Also, is there *ANY* other reason to use lenses on an adapter other than DOF? Sounds like any fast lens benefit would be negated by light loss in an adapter. And though I'm still too new to be convinced or understand the visual benefit of "the best glass", capturing any benefit through the not-as-great-glass after the adapter would loss that benefit. Am I correct?

Thanks again
 
the 16mm lens wont cover a large enough patch of the GG inside the adapter, and your footage would have an Evil vingette. unless thats what you want.... plus i dont think there are any 35 adapters now that have Angeniuex mounts.

Also, the Field Of View is what i seek mostly in the footage. The 35mm lenses, see differently that the tiny lens on the HVX does. Also, you can use things like, Tiltshift lenses, and lensababies, and nice distortion free 18mm Zeiss lenses, that have no barreldistortion, and can see practically 100degrees in an y direction. That and the color rendition and gamma curve that you cant quite get from the stock lens. the gg screens, have a tendancy to flatten the contrast a bit, to somethign that makes the video camera's recorded image seem more organic.

I think they just make the images prettier. plain and simple. I personally liek the look of 2 particular 35 adapters.... ( thoes of you know know me can guess my personal preferences.... haha) But the beauty of the 35 adpaters is that eacho f them responds to light differently, and act as a "film stock" of sorts. that and the combination of different lenses and their different light charachteristics, render images that cant quite be matched in "Magic bullet".
 
Thanks for the response. Your input really makes a lot of sense and
helps me out tremendously. Though my eye is not as trained as some, your description of what you see makes a lot of sense and puts perspective on what to look for.

I have many questions regarding lenses. Specifically I've had many many questions regarding optics that have gone unanswered. It appears you have an affinity towards the results obtained from 'bigger' lenses ("unlike the tiny one on the HVX"), what would your thoughts be on lenses intended for larger format cameras, cinema or still? I've tried to find information regarding the effects of lenses in different formats but haven't had much luck. Are there even 'bigger' lenses out there? Would they have an even more shallow DOF or is this simply a consequence of FOV? (That is a physics question, i'm not really trying to obtain a more shallow DOF)

It all gets confusing to me, I wish I could take time to create a detailed table for reference and learning for myself. Particularly I've been puzzled by why the perspective one gets looking at miniature models of a street like St.Marks place here in the city is hard to acheive in real life. There's definitely more to it than going wide and standing on the other side of the street. I'm learning about perspective correcting lenses and think an answer might be there but I have no money to test out theories.

I have one question you could answer very easily i'm sure. Here's the link to a post I made a few days ago. http://www.dvxuser.com/V6/showthread.php?t=93873&page=3 This area of optics is of great interest to me and I really appreciate all your input. I'm definitely saving this thread. Thanks.



For someone who hasn't had the experience to "see" for himself
 
Marshallarts said:
Thanks for the response. Your input really makes a lot of sense and
helps me out tremendously. Though my eye is not as trained as some, your description of what you see makes a lot of sense and puts perspective on what to look for.

I have many questions regarding lenses. Specifically I've had many many questions regarding optics that have gone unanswered. It appears you have an affinity towards the results obtained from 'bigger' lenses ("unlike the tiny one on the HVX"), what would your thoughts be on lenses intended for larger format cameras, cinema or still? I've tried to find information regarding the effects of lenses in different formats but haven't had much luck. Are there even 'bigger' lenses out there? Would they have an even more shallow DOF or is this simply a consequence of FOV? (That is a physics question, i'm not really trying to obtain a more shallow DOF)

It all gets confusing to me, I wish I could take time to create a detailed table for reference and learning for myself. Particularly I've been puzzled by why the perspective one gets looking at miniature models of a street like St.Marks place here in the city is hard to acheive in real life. There's definitely more to it than going wide and standing on the other side of the street. I'm learning about perspective correcting lenses and think an answer might be there but I have no money to test out theories.

I have one question you could answer very easily i'm sure. Here's the link to a post I made a few days ago. http://www.dvxuser.com/V6/showthread.php?t=93873&page=3 This area of optics is of great interest to me and I really appreciate all your input. I'm definitely saving this thread. Thanks.



For someone who hasn't had the experience to "see" for himself
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DOF is a function of the focal length, the Apeture and has a realtion ship with the field of view/imager size. 50mm Lenses, will have lets say, @ 5 feet, at F1.2 , 2" of DOF. Now if that 50mm lens is projecting on an imager the size of a 35mm film plane, like the GG of a 35 adapter, it appears to be a neutral standard field of view. However if the same 50mm lens is attached to an XLH1 for example that can use photographic lenses without a adapter, its recieving the same exact DOF, however the imager size is much smaller, only 1/3", so there fore the XLH1 is only reading a small patch from the middle of the larger projection area that the 50mm lens is capable of. So it SEEMS, as if the image is far more telephoto than its 35mm film plane counterpart. this is why Video camera lense have such short focal lengths, like 4.5mm. it needs a super super super Wideangle short focal length to "read a patch" that seems to look like normal wide angle field of view. its really confusiing, but once you wrap youre head around it, its like, "Ohhhhhhhhhhhhhh... now i get it...."

larger lenses, like medium format lenses, or "Vistavision"/Imax or military spy plane lenses, are HUGE, and presumably, would have a VERY shallow Dof for the same FOV, as its 35mm or Video counterpart. just because the lenses would have to be somuch bigger to ccomplish the same FOV.

My brain just imploded. so excuse me. :)
 
TimurCivan said:
I think they just make the images prettier. plain and simple. I personally liek the look of 2 particular 35 adapters.... ( thoes of you know know me can guess my personal preferences.... haha) But the beauty of the 35 adpaters is that eacho f them responds to light differently, and act as a "film stock" of sorts. that and the combination of different lenses and their different light charachteristics, render images that cant quite be matched in "Magic bullet".
Click to expand...

I'm curious about which two you like the most. What do you think about the Letus in comparison with the M2 and Beavis?
Jgastelb
 
At this point they are all about the same. I look ateach one as having different charachteristics. Like film stocks. The m2 gives a "dark" moody feel to footage, a little bit of a vingette, kinda "soft", with a golden color feel. The Sgpro, has really great colors, bright and clear and is really sharp, it seems to have the least "effect" on the footage, it sort of is like, stock fottage, just with Shallow DOF. The letus is soft and feels like intentianally dammaged film, it has a few defects, and sometimes some CA, but ive only used older models. The newer ones may have less effect. The Brevis to me looks a tad like the M2 just without a Vingette. Its golden and "dreamy". The Go-35 looks alot like the "G35" that everyone talks about. its warm, sharp, and has a subtle vingette that adds lots of Texture to the image. i use that one when doing closeups. it makes people look AMAZING. its like a promist + (shdof)

I personally chose the SGpro because if its lack of "effect" on the footage. Like for example if im shooting a commercial, and the clients wants Clean clean clean..... The SgPro delivers unaltered footage. where as with the M2 im gonna have that subtle vingettte that the client may not like. Plus a vingette can always be added in post. However for personal film makers, i say pick the one that delivers the footage you like. for some its the M2, for some its the Brevis for others (aka Awesome people, jkjkjk) its the SgPro....
 
TimurCivan said:
The letus is soft and feels like intentianally dammaged film, it has a few defects, and sometimes some CA, but ive only used older models. The newer ones may have less effect.
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I have the Letus35a and to me it doesn't look like damaged film but to each his own. I do like your footage though. I think it has a lot to do with the lighting as well. I would love to be able to see the same shot shot with the same camera, angle and lighting just changing the adapters and notice the differences.
Happy shootings!
Jgastelb
 
well thats the pont if a "35 adapter test" i wanna perform at somepoint. But im having trouble finding people with canon FD mounts. i wanna be able to use the same camera/lens/setting/lights and postition, and just change the adapter. a nice M2/Brevis/sgpro/go35/letus shoot out would be great fun.
 
I find it really hard to go back to the stock lens now that I've used an adapter. It really brings its own set of elements that make the picture closer to film -- in my humble opinion.
Jgastelb
 
Timur,

I appreciate all of your expertise and insight into the world of 35mm adaptors and lenses. I've just recently begun my journey with a Brevis & Nikkons. :)

D~C
 
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