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View Full Version : ULF shooters.Lens mount questions please !



Tri Tran
22-Apr-2010, 09:19
Hi ULF shooters,
Beside a custom order a flange for this beast which I might have to do so . Just received A 24 inches/F4.5 Petzval lens weighted 25lbs, 25 inches long and 8 1/2 inches diameter Flange threats (but NO flange) .In the mean time I would like to try it on the 8A Century camera . What's the best way to mount it? Some height adjustment accordingly with the camera if possible ( Just so to let you know I also have a tripod with gear column and a Majestic head for my 20x24) .How did the old folks mount the mammoth lens on the camera back in the days? A scan or a drawing it sure helps if you can.Thanks a bunch.

Pete Roody
22-Apr-2010, 10:50
At a minimum, you can thread an aluminum board and mount the lens directly to the board. I am assuming you have 9x9 boards.

GPS
22-Apr-2010, 11:47
Hi ULF shooters,
Beside a custom order a flange for this beast which I might have to do so . Just received A 24 inches/F4.5 Petzval lens weighted 25lbs, 25 inches long and 8 1/2 inches diameter Flange threats (but NO flange)
...
How did the old folks mount the mammoth lens on the camera back in the days? A scan or a drawing it sure helps if you can.Thanks a bunch.

Obviously, if the lens has flange threads, they mounted the lens with a flange...:rolleyes:
You should do the same - with a custom order flange as you suggest.
Never mount this lens of 25 lbs to an aluminum board with a threaded edge - unless you're a fool and the "board" is at least 15mm thick that is...:rolleyes:

benrains
22-Apr-2010, 13:11
If I remember correctly, the 8A takes 10x10 boards. A 9x9 board isn't going to cut it with a 8.5" diameter lens unless it's made out of something like steel. That said, I'm not sure I'd trust mounting 25 lbs of lens on a wooden 10x10 board even with a flange--nor would I necessarily trust the mounting hardware on the front of the 8A to hold up under that weight (especially with the torque of such a long lens.)

For starters I'd second the suggestion of getting a machined metal threaded lens board of a thickness comparable to the 8A lens boards. My 9x9 boards are around 11-12mm thick. I really don't think you'll have much trouble with aluminum, but you can ask the machinist for suggestions on an alloy with suitable strength. You could also opt for having it machined from a brass alloy or something like P20 steel, but those will of course add more weight.

I'd really love to see a picture of that monster.

eddie
22-Apr-2010, 13:35
WOW! TT i am going to call you....:)

i have my local machine shop make me threaded aluminum lens boards for my monsters without flanges.

i just picked this one up today. the hole in the lens board is 6 1/2 inches. the lens is a 22 inch lens and weighs 16 pounds. it is on an 8x8 inch lens board.

i find that even if you have the flanges for these lenses they quickly become too big for the "regular" lens boards. even 10x10 inch boards are not big enough to accommodate the flanges. i know this lens would never go on a 8x8 board with a flange. even 9x9 would be pushing it.

the most difficult time i have is running out of bellows. that is why i use the 8x10 and 11x14 deardorff studio cameras....plenty of bellows. this lens needs 46 inches on tight head shots and about 36 on shots just under 3/4. (too much for 8x10 century cameras)


cheers

eddie

edit. this photo (http://photo.net/photodb/photo?photo_id=10261131) is of a similar sized 25 inch lens. no worries about the aluminum....worry more about your screws pulling out of the front standard of your camera....LOL

eddie
22-Apr-2010, 13:40
two for fun. mounted on my DD 1114

Pete Roody
22-Apr-2010, 13:58
Don't underestimate the strength of aluminum. 6061 Alloy has an equivalent strength to structural steel (35-40 ksi yield). A 12"x12"x1/2" sheet costs about $60 from McMaster Carr. All you need is a machine shop to cut it to size and thread it.

BarryS
22-Apr-2010, 14:02
I agree with Eddie about getting a machine shop to do a one piece threaded lens board. I think the brass retaining plate at the top of the 8A front standard is only held in place with screws (at least there are no bolt ends on the inside of my 8A front frame). For a 25 pounder, I'd seriously consider replacing those screws with long bolts that go all the way through the standard and capping off the bolts with large washers under the nuts.

Tri Tran
22-Apr-2010, 17:50
Thank you all for your input and ideas. You guys are great!
Eddie, your lens looks very Sexy!
Before decide to build something solidly, I woud like to try the least expensive way to get the lens on the camera to see if I like the looks of its perform or it's a show piece. How about a craddle with some height adjustment for the lens to sit on and the camera will meet the lens like this picture.
http://img51.imageshack.us/img51/6175/19621580.jpg (http://img51.imageshack.us/i/19621580.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

This lens make my 27 inches Cooke lens looks like a Dwarf and on the right is a Hermgis Eidoscope #2 for your to compare.

http://img52.imageshack.us/img52/9524/45946667.jpg (http://img52.imageshack.us/i/45946667.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

Anything from 24 inches FL plus for head and shoulder shot to use with the Century 8A Double Bellow is still a liitle short for few inches as Eddie stated . That's why the original owner Mr Robinson was planned and custom order this Iron casted top hat board to use for this outfit. Smart man!


This one especially for Hugo and Hass . My finger crossed for Chamonix can come up with the new ideas of the 20x24 box camera for these Mammoth lens to shoot with . Totally functionality for easy assembly and disassembly when on field needed. That's what the beauty of Petzval lens for , not in the studio at least for me.

http://img59.imageshack.us/img59/5513/33601622.jpg (http://img59.imageshack.us/i/33601622.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

For security! This picture showed the back of the front camera that I have it installed a framing bracket to reinforce the front support.

http://img140.imageshack.us/img140/4348/33945395.jpg (http://img140.imageshack.us/i/33945395.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

The 27 Inches Cooke lens works great on the 8A for the last at least 70 years and has survived a several earquakes here in California.I'm looking forward to the next Beast on the camera and show you guys some pictures taken with it. Any others ideas please keep me posted.Thanks so much.

Tri Tran
22-Apr-2010, 17:54
A Top Hat Lens board was made by Taylor Hobson to use with this outfit as you see it gains another 4-5 inches bellow drawn which is perfect for head and shoulder on the 8A.
http://img203.imageshack.us/img203/2706/p1080302m.jpg (http://img203.imageshack.us/i/p1080302m.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

Tri Tran
22-Apr-2010, 17:58
Feel the weight? Please take a close look.
http://img263.imageshack.us/img263/6968/69185733.jpg (http://img263.imageshack.us/i/69185733.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

eddie
23-Apr-2010, 03:05
TT

that is a great lens. looks french. what is the maker....i can not quite make out the writing.

did you end up with the original flange for the Cooke or only the top hat.

i have deardorff 1114 that can handle these babies with no problem. send them to me for testing! lol!

IMO a top hat will take just as much money or more to make, and will really lever on the front standard.....but i guess you have been using the cooke on it for years and it weighs more......when i sue bigger lenses on also tie down the rear of the camera to the stand just to be sure it does not go over.....(never mind! i just looked at the photo and see you do exactly what i do).

a quick and dirty mount would be to bore out a hole size you need and then use hose clamps on the other side to secure it to the board. if you put 2-4 clamps together then you will have 2-4 points of "meat" to hold it to the board (the screw part of the clamp with give you some bite to hold with). you may not getthe tight shot you are looking for but it will give you an idea what you would get on film.

keep us posted.

eddie

Tracy Storer
23-Apr-2010, 19:00
Tri, that lens looks exactly like the one sitting on my bench ! "Mine" belongs to the customer for whom I'm modifying a Lotus 20x24. New front standard with 12x12 boards. Who is the maker on yours?

Tri Tran
23-Apr-2010, 19:49
Tri, that lens looks exactly like the one sitting on my bench ! "Mine" belongs to the customer for whom I'm modifying a Lotus 20x24. New front standard with 12x12 boards. Who is the maker on yours?

Wow, new front standard 12x12 that's the way to go.Lucky him! He's in the good hands. I will call you for more details. Do you have the flange for that lens? If so can I borrow overnight to try it on so you can make me a copy. I will forward you the pictures of F/S knob as we discussed. Thanks Tracy.

Dan Dozer
24-Apr-2010, 12:59
Hi Tri,

Here is how I mount my old lenses that don't have mounting flanges. Assuming you are using a wooden lens board - cut a hole in the board a little larger (about 1/16") than the outside diameter of the threads on the lens. I use a Dremmel for final sanding to get the hole the right size and get the surface smooth. From the local craft store (I get mine at Michaels), get a sheet of black craft foam. It's 1/16" thick and costs about a dollar for a sheet that is about 12" x 16". Cut a strip of the foam that is at least the thickness of the lens board. Line the hole in the board with double sided scotch tape. Mount the strip of foam on the around of the inside of the hole in the board on the tape. Then you just screw the lens into the foam lined hole in the board. As long as you didn't make the hole too large, the lens will mount very securely.

Now, I haven't tried this method with any lenses nearly as large as yours, it really works well for the lenses that I have done it with (like the Heliar and the Eidoscope). I would think that as long as you have enough of a thickness of threads to work with on the lens (maybe 1/4" or more), this method will probably work. If the depth of threads is smaller than that, it might need a threaded mounting flange to work. However, for the investment of a lens board and the craft foam, it's probably worth trying before spending the money at the machine shop.

eddie
25-Apr-2010, 02:09
oh! i just remembered how a friend mounts his flangeless lenes. he has a hole in the board about the right size and the "glues" them in with silicone (RTV). after it hardens it is very secure. best part is the silicone is easily cleaned from the lens. use it liberally.

eddie

GPS
25-Apr-2010, 05:21
Hi Tri,

Here is how I mount my old lenses that don't have mounting flanges. Assuming you are using a wooden lens board - cut a hole in the board a little larger (about 1/16") than the outside diameter of the threads on the lens. I use a Dremmel for final sanding to get the hole the right size and get the surface smooth. From the local craft store (I get mine at Michaels), get a sheet of black craft foam. It's 1/16" thick and costs about a dollar for a sheet that is about 12" x 16". Cut a strip of the foam that is at least the thickness of the lens board. Line the hole in the board with double sided scotch tape. Mount the strip of foam on the around of the inside of the hole in the board on the tape. Then you just screw the lens into the foam lined hole in the board. As long as you didn't make the hole too large, the lens will mount very securely.

Now, I haven't tried this method with any lenses nearly as large as yours, it really works well for the lenses that I have done it with (like the Heliar and the Eidoscope). I would think that as long as you have enough of a thickness of threads to work with on the lens (maybe 1/4" or more), this method will probably work. If the depth of threads is smaller than that, it might need a threaded mounting flange to work. However, for the investment of a lens board and the craft foam, it's probably worth trying before spending the money at the machine shop.

Great! How about replacing the foam with old socks??
You're speaking 25 lbs of a precious lens... It's enough if the lens board is not tightened enough and the whole thing goes its way in unwanted tilt... :rolleyes:

Tri Tran
25-Apr-2010, 07:55
I definitely need a flange.Most of the lens have no flange I usually glued it to the board with Epoxy as Eddied suggested but not for this one.
Dan, the foam works for Eidoscope and similar lenses sizes and weights but I doubt it to support 25 lbs . As GPS stated , if this lens is not mounted properly , it can end up on the floor or inside the bellow.I'm going to miter 2x4 to make a craddle for now as Dwayne Ealy suggested, a quick and dirty way to see how the lens looks like.Thank you all.

eddie
25-Apr-2010, 14:21
har har har. you can glue it in and then use a chin strap (http://www.largeformatphotography.info/forum/showthread.php?t=45678&highlight=chin+strap) to secure it up....but you need to pay patent royalties! LOL!

Tri Tran
25-Apr-2010, 21:44
Lens mounted and here's my first try.11x14 back. Please let me know if its worth it to make the flange.Thanks .

http://img231.imageshack.us/img231/3817/tavor.jpg (http://img231.imageshack.us/i/tavor.jpg/)

eddie
26-Apr-2010, 03:23
nope. not worth it. send it to me i will pay the postage! LOL!

so far so good. i find these big lenses take a bit of a "get to know each other" period. being so long and with such shallow DOF combined with movements in the camera (read sail here) and/or subject adds to the learning curve.

so how did you finally attach the monster?

eddie

Tri Tran
26-Apr-2010, 22:20
Eddie. The lens is packed and ready to ship. What's your CC number please? :)
Here's my quick and dirty set up for this lens. It's steady but not pretty. Simply pratical .


http://img269.imageshack.us/img269/8405/monopod.jpg (http://img269.imageshack.us/i/monopod.jpg/)





nope. not worth it. send it to me i will pay the postage! LOL!

so far so good. i find these big lenses take a bit of a "get to know each other" period. being so long and with such shallow DOF combined with movements in the camera (read sail here) and/or subject adds to the learning curve.

so how did you finally attach the monster?

eddie

eddie
27-Apr-2010, 03:27
awesome set up! such fun.

tell you what. i will send you an extra 48,000$ and pay the shipping. you can keep 1/2 of the money as a way to thank you for helping my ailing father in nigera. ;)



Eddie. The lens is packed and ready to ship. What's your CC number please? :)
Here's my quick and dirty set up for this lens. It's steady but not pretty. Simply pratical .


http://img269.imageshack.us/img269/8405/monopod.jpg (http://img269.imageshack.us/i/monopod.jpg/)