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G1, B+W, Cine Lenses, & 1 Color Pic

wjlapier

Member
Bill,

If this is the lens that took the picture of the 2 vases on columns you posted in the Fun with 4/3rds cameras/ Image Thread, I would strongly disagree. While there was no vignetting, the sharpness is falling off so markedly from the center (smearing) that it my opinion it is unusable on a G1. This is certainly not what I would call Full coverage.

You wrote yourself in answer to my question I'm noticing that, with the SOM anyway, that when shot wide open the center is sharp as it should be, but from there it get's soft or smeary.

Please be more critical and objective about your lenses. One tends to love one's own babies and to justify to oneself the money spent, but this database is meant to guide other users in their buying decisions and not to mislead them.

Thank you
Kind regards,
Peter
Peter, all I was referring to was lack of vignette as in the case of the Kern 10 and 16. I agree we need to be objective when evaluating these lenses. Maybe there can be a place for comments such as mine regarding the edge softness ( smearing ) of the Som when shot wide open, and maybe we need to describe what "full coverage" means. We are in the infant stage of this database and objectivity is key, I agree, but changes should and will be made.

Thanx for bringing that to everyone's attention. I think it is an important idea that needs to be discussed a little more.
 
Peter, all I was referring to was lack of vignette as in the case of the Kern 10 and 16. I agree we need to be objective when evaluating these lenses. Maybe there can be a place for comments such as mine regarding the edge softness ( smearing ) of the Som when shot wide open, and maybe we need to describe what "full coverage" means. We are in the infant stage of this database and objectivity is key, I agree, but changes should and will be made.

Thanx for bringing that to everyone's attention. I think it is an important idea that needs to be discussed a little more.
Bill,

Sorry for being a bit aggressive in my post, it may have been my personal letdown with C-mount lenses I spent money on and that are in my opinion totally unfit to be used on the G1.

Severe smearing is as bad as vignetting and in my opinion the database should provide guidance to prospective buyers of c-mount lenses in terms of "fitness for use on the G1". I agree that this is not an easy task and that it should be discussed further.

Perhaps we should add pictures showing the defects, for vignetting a white wall (or ceiling) and for smearing an example like the one you had posted with the 2 vases of the SOM Berthiot.
 

wjlapier

Member
Bill,

Sorry for being a bit aggressive in my post, it may have been my personal letdown with C-mount lenses I spent money on and that are in my opinion totally unfit to be used on the G1.

Severe smearing is as bad as vignetting and in my opinion the database should provide guidance to prospective buyers of c-mount lenses in terms of "fitness for use on the G1". I agree that this is not an easy task and that it should be discussed further.

Perhaps we should add pictures showing the defects, for vignetting a white wall (or ceiling) and for smearing an example like the one you had posted with the 2 vases of the SOM Berthiot.
I was thinking the same thing. A shot of a white wall to show vignette, and a shot showing the smearing. Maybe refrain from comments like "not usable on a G1" because, even though they may not be useable for one person, someone else might like the effect it produces.
 
I was thinking the same thing. A shot of a white wall to show vignette, and a shot showing the smearing. Maybe refrain from comments like "not usable on a G1" because, even though they may not be useable for one person, someone else might like the effect it produces.
I think one should make a comment but it should be made clear that it is the testers personal opinion and perhaps be expressed in more "politically correct" language. Although I think that we are in a private forum and one should have the right to voice ones (technical) opinions as long as they are not offensive.
 
M

milapse

Guest
Greetings all (first post here..)

I'm here to help with the lens data base. Here's my current collection (I'll update the info as I gather it, some will be repeats):

Schneider 10mm/F1.8 (very sharp)
machining: no
coverage: no

Cosmicar 12.5/F1.4
machining: yes
coverage: no

Schneider 16mm/F1.4 (on it's way)
machining: I don't think so
coverage: 18mm (so I've read)

Angenieux 25mm/F0.95
machining:no
coverage: almost 16:9

Soligor 25mm/F0.95
machining:no
coverage: almost 16:9

Schneider 50mm/F2 (crazy sharp)
machining:no
coverage: yes

I think we should try to pin down the image circle on these lenses because I do find the non coverage lenses 'useful' albeit I'm coming at this from a timelapse/cinematic perspective (and thinking ahead to the GH1) for the following purposes (using peters 25/1.5 example):
This is how I've used the Schneider 10/1.8 with awesome results


This is how I see the GH1 with c-mounts being very interesting for 720p production...
 
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f6cvalkyrie

Well-known member
Severe smearing is as bad as vignetting and in my opinion the database should provide guidance to prospective buyers of c-mount lenses in terms of "fitness for use on the G1". I agree that this is not an easy task and that it should be discussed further.

Perhaps we should add pictures showing the defects, for vignetting a white wall (or ceiling) and for smearing an example like the one you had posted with the 2 vases of the SOM Berthiot.

Hi,

I just wanted to give some input on these lens tests.

IMHO, if we do create a database of lenses "fit for use on G1", we can not limit ourselfs to "looking if the image fills the sensor". We also have to care about other parameters such as resolution (if not why do we have MP sensors in our cameras ?), distortion, aberration (sferical & chromatic), flare, ghost images, diffraction, ..

And we have to do so in a coherent manner, Peter should test his lenses the same way as Bill does, etc.

Test patterns for lens test do exist, they are available for download from several sites, however, mainly not free of charge. But we could make something for ourselfs. It is not very important what it is or how it looks like, but it has to be the same for every tester.

Also, we need to define standard test conditions, like : camera on a tripod, exposure time 1/60, HQ jpg setting, ... so that "shaky hands" or postprocessing do not influence the results etc.

If we are ready to go down that road, our database will be a useful one.
Otherwise, people spending money based upon our "recommendations" might become very unhappy visitors at this forum.

I'm ready to participate setting up a procedure, however, I don't own such exotic lenses, so I could not help in the testing.

C U
Rafael
 
Hi,

I just wanted to give some input on these lens tests.

IMHO, if we do create a database of lenses "fit for use on G1", we can not limit ourselfs to "looking if the image fills the sensor". We also have to care about other parameters such as resolution (if not why do we have MP sensors in our cameras ?), distortion, aberration (sferical & chromatic), flare, ghost images, diffraction, ..

And we have to do so in a coherent manner, Peter should test his lenses the same way as Bill does, etc.

Test patterns for lens test do exist, they are available for download from several sites, however, mainly not free of charge. But we could make something for ourselfs. It is not very important what it is or how it looks like, but it has to be the same for every tester.

Also, we need to define standard test conditions, like : camera on a tripod, exposure time 1/60, HQ jpg setting, ... so that "shaky hands" or postprocessing do not influence the results etc.

If we are ready to go down that road, our database will be a useful one.
Otherwise, people spending money based upon our "recommendations" might become very unhappy visitors at this forum.
Rafael,

I totally agree with the necessity of consistent test patterns. However, I have a major doubt about your suggested approach. Most of us participate in this forum for the fun of it. We like sharing our experiences but I wonder whether anyone here can and would invest the time and effort it needs to test lenses in the professional way you suggest.

Shooting a white wall or ceiling and posting a few pictures we have not made specifically for the purpose of testing is one thing, following an exact protocol might be more than anyone is ready to do.

I have 2 c-mount lenses and am waiting for a third one to come. After that, having looked at some of the results posted here and my own letdown with the 25mm/1.4 Schneider Cine-Xenon, I intend to close the c-mount chapter.

There are other format lenses that pose much less problems and give excellent results on the G1: Leica R, Nikon F, Pentax; I have become tired of throwing money at a potentially unsatisfactory category of lenses and shall let others play with their gadgets. I prefer to use a camera for making (hopefully good) photographs. I shall be pleased to share them, as well as my knowledge, as long as it is for my pleasure.

Cheers
Peter
 

djonesii

Workshop Member
First stab at a G1 C Mount Lens Compatibility List:

Monza;

I would suggest that you add a place for a URL to see samples from the lens. This way, the table outlives the thread.

Moderator ... Could that link then be made sticky like the adapter one?

Dave
 
R

Ranger 9

Guest
Test patterns, whether downloaded or homemade, don't furnish any useful information unless you're seeking a lens specifically for photographing flat, two-dimensional objects oriented parallel to the image plane at a fairly close distance.

(Otherwise you're just gathering info that seems impressively precise, but isn't really accurate. Illustration of precision vs. accuracy: Suppose I put a profile on a dating website stating that I'm six feet, 3 and one-fourth inches tall, weigh 177 lbs 6-5/8 oz, and have a net worth of thirty-one million, six hundred seventy-two thousand, three hundred forty dollars and fifty-seven cents. All those figures are extremely precise, but none of them are accurate!)​

Most of us are interested in messing around with these C-mount lenses not in the interest of best photographic performance (for which we'd be better off with the kit lenses or Four Thirds lenses used via an adapter) but for the impressionistic or atmospheric qualities they provide.

For those types of use, it's important to know whether a given lens will require machining or not (although this may depend on the type of adapter you use) and it's useful to know whether or not you'll get dark corners at various format sizes. One-word subjective evaluations of corner smearing and bokeh might be useful as long as everyone remembers that they are subjective.

But beyond that, I think the only really useful information comes from looking at photos that make use of the best qualities of a particular lens, regardless of what those qualities might be. I don't think we can come up with a useful quantitative way to evaluate these lenses other than for their simple mechanical and optical properties.
 
Test patterns, whether downloaded or homemade, don't furnish any useful information unless you're seeking a lens specifically for photographing flat, two-dimensional objects oriented parallel to the image plane at a fairly close distance.
IMHO there are good lens tests that are helpful for users. I know Sean Reid is not liked by everyone here and I hope I shall not start a flame war. Nevertheless, I think his (pay) review site is a good example. Although I do not always agree with his conclusions, his numerous shots taken under different conditions help me in judging what is important for me.

Again, he is doing this professionally and asks to be paid to enter his site. I do not think the users of this site could devote the necessary time and effort for such an approach, as desirable as it may be.
 

monza

Active member
Well, I know I barely have the time to maintain a database at all, let alone one that has a ton more information. :) The original idea was to track whether a given lens needed machining, and whether it covered the sensor. That would at least make it somewhat easier for people to avoid lenses that require machining, or avoid lenses that don't cover the sensor (although personally neither of these are limiting factors for me, I know they may be limiting factors for others.)

As far as lens performance, that is an entirely different can o' worms. :)

As an aside, I'm not closing the chapter on cine lenses. There is more research that needs to be done, I'm quite sure there are some extremely nice, sharp, fast, ergonomically excellent cine lenses that can fill the hole, until Panasonic finally delivers the 20/1.7 and the 7-14. And even after those lenses are available, there still may be some cine lenses that offer something that none of the Pana lenses do (more speed, price, character, bokeh, etc.)

One such lens is the 25/1.9 Xenoplan which from two different sources is reported to be extremely sharp and offer full coverage and doesn't require machining. Others include the superfast f/0.95; surely Panasonic is not going to offer something close to that. :)

One more note: when the GH1 comes out, cine zooms will go through this same process. The 14-140 lens is quite slow.
 
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wjlapier

Member
How about this for a reference:

Kern Switar 10/1.6; 16:9 ratio. Wide open on top and stopped down to f/16 on bottom. Even though the 10 stops down to f/22 I think I should keep it at f/16 for almost all lenses I have. I'll check at 4:3 and 3:2, but most of the wides perform best at 16:9, so that is where I will do these tests, and I'll note otherwise.
 
M

milapse

Guest
Kern Switar 10/1.6; 16:9 ratio.
That's a typical 'standard 16mm' lens with a image circle of 14mm

This is great information IMHO! keep it coming. I'll add mine as well.
 
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M

milapse

Guest
Here is the Schneider Cinegon 10mm F1.8
Image circle 14mm (standard 16)
 

LizaWitz

New member
A wall with some speckling on it is a good test pattern, just get the lens close enough to see the pattern and I think you'll kill multiple birds with one shot.
 

Photomorgana

New member
Hi everyone,

I am brand new here on this forum, so let me begin with a compliment on great work you doing in regards to G1 and C-mount lenses. Much Respect :salute:

Now, let me bring up my 2 cents. Ive tried a good dozen on C-mount lenses on G1 and here is my premature conclusion.

I dont see a point to use anything less than 25mm as it wont cover the sensor and cropping proved not getting any wider results that that of a 25mm lens. There might be exceptions that I dont know of.

I do like results I saw from 75mm lenses and beyond, but long lenses are not ergonomically pretty and not bright enough. :) 100mm f2.8 would be as long as I would go. but its just me.

So, my opinion, there is room for bright 25 to 100mm c-mount lenses on G1. By bright I mean 0.95 to 2.8. Maybe f4 if you really like the lens :p

I dont have any formal benchmarking that Im using for lens testing, but from my visual observations on my NEC-2070NX monitor, I liked some lenses better than others :) go figure...

I was able to pick 7 lenses that struck me the most as being the best. I will try to come up with some sort of test items and post some samples after the weekend is over, maybe on Tuesday. Hopefully weather will be sunny for outdoor shots.

Hint... there will be 4 Kerns, 2 Angenieux, 1 Cooke. I didnt like some CCTV lenses I tried, they tend to have small resolution. Dont wanna mention any brands not to upset any one.

Regards, keep up the good work.
 
E

emory

Guest
This is a fascinating thread, and I can't wait for the GH-1 to arrive so I can try shooting video with my two old C-mount lenses.

- Elgeet 13mm 1.5 (has anyone tried this one on the G-1?)

- Lytar 25mm 1.9

Although the Lytar is in pristine condition, its focussing ring is rather stiff, getting progressively stiffer as it's turned toward infinity. Probably dried-out grease.

There are three small screws at the base of the mount and one screw on the ring on which the depth of field scale is printed. Has anyone had any experience getting the focussing ring off to clean and lubricate the (hopefully not helical) focussing threads? I'm a bit reluctant to remove the srews. I've tried (very cautiously) to let some lighter fluid seep in between the rings, but with no real success.

I've tried googling this -- again without success.

Does anyone have any pointers or perhaps a link that might be of help?

Thanks.

emory
 
M

milapse

Guest
- Elgeet 13mm 1.5 (has anyone tried this one on the G-1?)
Still no info on that one... I'm guessing it will fit without modification looking at the design and I'd bet it's around 15mm IC
 
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