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peter k
Joined: 26 Dec 2009 Posts: 207 Location: Sedona Az
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Posted: Tue Jan 07, 2014 8:10 pm Post subject: Take 3: I'm confused: Carl Zeiss, Protarlinse Vll f 35cm |
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Need some clarity, trying to grasp and learn, lenses, image circles, focal lengths ect. Thanks for the help!
Use with a wonderful (light tight and fully functional) 4x5, reassembled 1950 Pacemaker:
Both lenses are VII 35cm lenses. Can focus with both, or just one on front.
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1) 350mm = 13.75+" ... How the heck is this 35cm lens, in focus appox. 12" from the surface of the ground glass?
2) Missed this the first time it was posted, if both are 35mm lenses, wouldn't they both have the same focal length, not just one 290mm, and the other 350mm?
Both of them together would in fact be close to 180mm.
(p41: http://www.cameraeccentric.com/html/info/zeiss_4.html
states that the combined combination of a 350 & 350 = 200mm
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Reference from original post: 03-22-2012,
http://graflex.org/helpboard/viewtopic.php?t=6264
Quote: | "Your lens is a double Protar composed of two "Protar lenses" (Zeiss parlance). With both cells in place, its focal length is is around 180 mm. Each of the two cells can be used without the other. One has a focal length of 290 mm, the other 350 mm." ... "No Graphic has enough extension to focus a 29 cm non-telephoto lens, let alone a 35 cm. Protars are not telephotos." |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Wed Jan 08, 2014 1:12 am Post subject: |
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Let's start all over. You are confused and your have given conflicting information.
Do you have one cell engraved 35 or 350 and another engraved 29 or 290?
If so, you have a Double Protar with unequal cells. Each cell can be used by itself and the two can be used together, mounted in a shutter.
The cell engraved 35 or 350 is a 350 mm f/12.5 lens.
The cell engraved 29 or 290 is a 290 mm f/12.5 lens. Your Graphic can focus lenses with focal lengths up to around 12 1/2 inches (317 mm) to infinity. If you mount the 29 cm (or 290 mm) cell in the shutter I think you have, it will focus to infinity on your Graphic.
The cell engraved 35 or 350 is a 350 mm f/12.5 lens. Your Graphic can't focus it to infinity, it is too long.
The two cells together make a 180 mm f/7 lens. Your Graphic can focus it to infinity. |
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peter k
Joined: 26 Dec 2009 Posts: 207 Location: Sedona Az
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Posted: Wed Jan 08, 2014 3:24 am Post subject: |
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Ok.. clarity:
Quote: | Let's start all over. You are confused and you have given conflicting information. Do you have one cell engraved 35 or 350 and another engraved 29 or 290? |
Good idea, and in that process found out that question 2) answered!
The conflicting information, came from the original post, giving a link to E-bay as an example of the type of lens I had, and what was so special about it.
IT IS NOT MY LENS! It consisted of a 29mm & 35mm lens.
Mine consists of two 35mm, which I related to later in the same post.. on:
Posted: Sat Mar 24, 2012 5:10 am Quote: | Where did you get that from... from the e-bay item?
I didn't post any serial numbers? But here they are..
Compur Lens.. # 258646
# 493451 what is now the outer lens
# 461454 inner lens |
but did not state they were both 35mm ... continuing the conflicting information. Guilty as charged!
Quote: | The cell engraved 35 or 350 is a 350 mm f/12.5 lens. Your Graphic can't focus it to infinity, it is too long. |
Well, there's something going on ... with one 35mm lens on the front, it focuses at about 12", either one. So first question remains..
1) 350mm = 13.75+" ... How the heck is this 35cm lens, in focus appox. 12" from the surface of the ground glass?
( I've got an image on Postimage.org, that shows both 35mm lenses, but see no add image link here.) |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Wed Jan 08, 2014 3:58 am Post subject: |
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When you click on the post reply or new topic on the left there is a section called options of which BB Code is one and is a highlighted link, click on it, follow the instructions for adding an image to your post.
Throughout your post you refer to the cells as 35mm and 35cm. Do you have both 35mm and 35cm cells? _________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Wed Jan 08, 2014 1:56 pm Post subject: |
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Charles, he's a little confused or an exceptionally sloppy typist. 35 cm, 350 mm, not 35 mm.
Peter, thanks for the clarification. So you have two 35 cm/12.5 Protar Ser. VII cells. According to this http://www.cameraeccentric.com/html/info/zeiss_8.html the two together make a 205/6.3.
Where are you measuring from?
I ask because with the lens focused at infinity, the distance between the film plane and the lens' rear nodal plane is 350 mm. The rear nodal plane need not be close to the glass elements. Just accept this, use your lens and be happy.
By the way, Zeiss recommends that when a single Ser. VII Protar cell is used it be mounted behind the shutter, not in front of it. |
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peter k
Joined: 26 Dec 2009 Posts: 207 Location: Sedona Az
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Posted: Wed Jan 08, 2014 3:38 pm Post subject: |
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Lets see if this works..
[img]http://postimg.org/image/yx2erpy9x/[/img]
Thanks 45pps.. yes ... sigh... they are 35cm, only.
Dan.. or MrDF... a note: I grew up 4 miles, on the same Jersey side you live on, from de GW Bridge.. and ur bringing up the old NYorker... Ha.. (New York Sarcasm), that my poor native Arizona born wife, is trying diligently to cure me of. But its hard, and yes I'm a little confused, that's why I'm asking de questions. Your very qualified in answering them, and I appreciate your help, experience and expertise, from the past, now, and hopefully in the future. But please use your hankie and blow the 'I can't suffer fools gladly' comments into it, and stow it in the back vertical pocket.
Thankfully, Amen ...
Now where were we, oh yes clarity!
I'm measuring from the front of the lens to the front surface of the Ground Glass, its about 12", focused on infinity. So: Quote: | The rear nodal plane need not be close to the glass elements. |
Ok did some research on nodal points, and have a very beginning understanding.. but could you give me some references to grok, how the heck it can still work!
Fascinating!!
Meanwhile, I will accept this, and use the lens happily, but not to the extreme extent of using by cell phone to take pictures, at forty miles an hour as I tour through a scenic wilderness, being conceptually dead.
That's why I love film, its complexity, and simple rendition of light into a physical seeing reality, without instant gratification.
Thank you both for your help and input, always, even with a twist of NYorker, thrown in, as it can add jest to the comments at times. ![](images/smiles/icon_wink.gif) |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Thu Jan 09, 2014 12:51 am Post subject: |
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Peter, I'm sorry, you're mistaken again. Although I live in the state of exits and abrasion I grew up on the midwest's eastern fringe and was formed there. I was grumpy before I moved east.
I don't understand why, but photographers who post on the Internet seem to be fascinated by optics. I've done a lot of closeup work, and there knowing the rules helps know what just won't work. Otherwise what I know about optics has had little impact on how I work as a photographer or on the pictures I've taken.
Nikon taught me most of what I needed to know about taking pictures that come out as I want. My first real camera was a Nikkormat; a little pamphlet, that I still have, for beginning photographers came with it. It described the controls, explained what effect the settings had on the results, gave examples -- series of pictures taken at different settings -- and gave homework assignments. I did the homework, I tried things out.
In those days there was no Internet. Knowledge was in books and magazines that lived in libraries. Also in gurus, but they're hard to find. I had one self-proclaimed guru, a leicanut, ready to hand but, as I've already said, he was obviously nuts.
Instead of listening to him I went to the library and discovered that Modern Photography and Popular Photography magazines ran a two year cycle of educational articles. So I absorbed two years of MP. And I tried things out.
If you want to read a book that might help you learn to control the photographic process from start to finish, buy a copy of A. A. Blaker's Field Photography. I bought mine shortly after it came out, still consult it occasionally. I used to give copies of it to beginners I saw as promising and sunk in ignorance. |
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peter k
Joined: 26 Dec 2009 Posts: 207 Location: Sedona Az
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Posted: Thu Jan 09, 2014 2:13 pm Post subject: |
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Thank You very much for the reply... and loved the quote of "... exits and abrasion", ... it fits Jersey and NY city, well. But there are times, when those character traits, twist into incredible forgiving and spontaneous combustion, that can put the rest of the whorl of the world into amazement! And there is nothing, anywhere, or anyplace that can match it! ... When it does take place!
Yes, I have become fascinated by optics! Blame it on the speed. You can't take it for granted anymore, in and out goes the lens. Optics!
Similar to you, I cut my teeth, also on, a Nikromat, also a Photomic ftn, but that came about as I became retarded, I mean, a retiree. MAKING ME VERY MUCH A NEWBIE. With the 35mm its still just change lenses, hardly a thought or effort, free as a bird on the wire.
Never thinking of it, just using it.
But it was the Speed 3x4, at first, and now with the 4x5, that I can use two of the three combinations of this crazy lens, that has made me go deep into my annal analytical temperment. Wanting to know why?
Your right!
So what!
Use it an enjoy it! Get to know what you can do with the two lenses, and the then just compose the darn picture. That's what your here fer you idot!
Sigh.. soooo... forgetaboutit!!!
Next..
Well your my lens Guru, and obviously nuts, so I'll take your advice.
Thank you.. |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Thu Jan 09, 2014 4:54 pm Post subject: |
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Peter, I'm not a guru. Al Blaker is a guru, and a good one. Buy a copy of Field Photography. You should be able to get a copy inexpensively through, in alphabetical order, abebooks.com, alibris.com, amazon.com and other sites that give access to on-line booksellers. |
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Henry
Joined: 09 May 2001 Posts: 1636 Location: Allentown, Pennsylvania
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Posted: Thu Jan 09, 2014 8:02 pm Post subject: |
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Somewhat off-topic, but on the periphery. New Yorkers are great! And much nicer, overall, than they used to be. "Some of my best friends",...etc. I graduated from Ft. Hamilton High School, class of '59, and though I lived but a scant two-and-a-half years in the city altogether (Manhattan and Brooklyn), I cherish the memories. I wouldn't live in NYC today if you paid me, but back then it was great. Then I married a New York girl from way upstate, St. Lawrence County, different country entirely, and finally settled in e. PA (43 years and counting)---close enough to visit the City, but even closer to my beloved Philadelphia and its wonderful sports fans ( ). NJ is nice, too, the closer you get to PA, but still an inconvenient obstacle to getting into the City. But I wouldn't live anyplace but here! |
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