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10-28-2009, 03:57 PM   #1
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LBA on the cheap: DIY lenses

Here's my latest experiment:





Itís made from the lenses from some broken dollar-store binoculars, some black paper, tape, and some PVC pipe.

Here are the results:



Both lenses in this picture were at f8. better results can be had with the homemade lens at smaller apertures (but focussing becomes difficult). At large apertures this lens can be used as soft-focus.

100% crops:
homemade lens:



18-55@55mm:


The results are pretty good considering the lens was make from the lenses of dollar store binocolars. It is probably similar to the lensbaby without tilt-shift (thats my next project)

If anyone has done anything similar or has any other DIY stuff, please post it.

10-28-2009, 04:20 PM   #2
Ash
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You're nuts!
Clever idea - good for fun. Wouldn't be doing weddings with it though.
Now all you need is some of that mult-coated glass to put in it, design your own focusing mechanism and you have a winner!
10-28-2009, 05:38 PM   #3
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Very well done Nick!

In a similar vein is Veijo Vilva's retro stuff. Here (wait a second for auto-scrolldown) he has put an old Vest Pocket Kokak lens onto a hollow lens housing. Results are similar to your lens, there's a pictorialist soft look to the photos.

Respect, Georg (the tinkerer)
10-28-2009, 07:22 PM   #4
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Damn, you stole my line -- LBA on the cheap. Another bravo. Whatever that you have there, please tell us what sort of thing is in the pictures so that we know it it not a toilet plunger.

Coffee is on me -- this is hilarious week for PF. Nick, you are the man.

Warmest,
Hin (the Man)

10-29-2009, 04:01 AM   #5
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Here is an item to go with the DIY lenses. This happens to be a 76mm extension tube, made from PVC. It is PK on one end, M42 on the other. Black flocking on the inside to cut stray light.
Zero bucks, made from stuff in the junk box.
10-29-2009, 08:15 AM   #6
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The PVC tube & standard lens coupling fittings like filter rings, m42 adapters, etc are an important part of the DIY picture, but the biggest challenge for me is to find objective lenses that justify the effort.

The largest achromatic close-up lenses one can find are around 75mm diameter for a 500 mm focal length; this yields at best about 500/75=f/6.7; such lenses are not inexpensive.

A Sigma achromatic closeup lens with an open diameter of 48mm, fl=625mm, is f/13, so not too handy for birds, etc.

High end overhead projectors are a possible source of long, large aperture, excellent lenses - one might be able to locate such a thing in a scrap pile as overhead projectors are a thing of the past. I've seen reference to 500mm, f/4 triplets.

The relatively common 3M 9800 overhead projector has a 342mm triplet - unfortunately, I don't know its diameter... but it is likely to be fast. Another source of fast long lenses might be in projection type LCD units like the Barco projectors.

If anyone has ideas regarding where to get excellent, fast, long lenses for cheap, I'd sure like to hear about them.

Dave in Iowa
10-29-2009, 08:21 AM   #7
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Try looking through this site. Surplus Shed

I have built many different combos from their parts. Including my 600mm F6.
10-29-2009, 09:10 AM   #8
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QuoteOriginally posted by hinman Quote
Damn, you stole my line -- LBA on the cheap. Another bravo. Whatever that you have there, please tell us what sort of thing is in the pictures so that we know it it not a toilet plunger.

Coffee is on me -- this is hilarious week for PF. Nick, you are the man.

Warmest,
Hin (the Man)

Yeah I stole your line. Sorry Hin. Thought it would make a good titile for this tread.

10-29-2009, 09:15 AM   #9
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QuoteOriginally posted by wildlifephotog Quote
Try looking through this site. Surplus Shed

I have built many different combos from their parts. Including my 600mm F6.
Your 600m f6 sound really interesting. Could you post a picture of it or something taken using it?
10-29-2009, 09:30 AM   #10
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It uses a 2" fringe killer filter to kill CA. I've got it to focus down to 20 feet.
The photo is of a street about 1/4 mile away.
And no, the focuser is not curved. I was using a 24mm lens too close.

Last edited by wildlifephotog; 09-27-2013 at 07:21 AM.
10-29-2009, 01:14 PM   #11
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QuoteOriginally posted by wildlifephotog Quote
It uses a 2" fringe killer filter to kill CA. I've got it to focus down to 20 feet.
The photo is of a street about 1/4 mile away.
And no, the focuser is not curved. I was using a 24mm lens too close.
WOW! very cool. looks like it works well too. The fringe killer filter is a good idea.
10-29-2009, 03:14 PM   #12
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QuoteOriginally posted by newarts Quote
High end overhead projectors are a possible source of long, large aperture, excellent lenses - one might be able to locate such a thing in a scrap pile as overhead projectors are a thing of the past. I've seen reference to 500mm, f/4 triplets.

The relatively common 3M 9800 overhead projector has a 342mm triplet - unfortunately, I don't know its diameter... but it is likely to be fast. Another source of fast long lenses might be in projection type LCD units like the Barco projectors.

If anyone has ideas regarding where to get excellent, fast, long lenses for cheap, I'd sure like to hear about them.

Dave in Iowa
Dave, I'm not very optimistic about scavenging lens elements from the Barcos. The last one I helped lift into place had an $80k price tag on it so you'd be better off cutting up a new Leica R telephoto. Folks are pretty proud of their Barcos. My first thought with your comment was to seek out used Buehl (sp?) slide projector lenses at camera shows.
10-29-2009, 03:21 PM   #13
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wildlifephotog, love the brass thingies on the blue rings, maybe from the royal navy ?

Dave / newarts, have a look for any enlarger lenses (they usually come cheaper with the enlargers, but enlargers are bulky !). Also, slide projector lenses could serve well and cost you a penny or two. I've seen old Leitz projectors for 6x6 slides and they had interchangeable lenses up to 2.8/300mm.

It's probably best to sniff around where an institute/college/school puts out those things in major rebuilds or moves of the faculties / buildings you name it. Always good to know either rich or very educated people :-)

Georg (the scavenger)
10-29-2009, 03:29 PM   #14
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Plywood rings, brass hinges, steel bar. All scrounged and put to use. I never spend more than needed to build a project. Too much stuff needs recycling.
The 600mm cost me a grand total of $120.00. I had to buy the front element and 2" focuser.
10-29-2009, 03:32 PM   #15
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Our university surplus (Iowa State University) now has a few Barcos for sale for around $250 each I think.

Buehl Opaque projectors (Mark IV for example) have about 500mm f/3.6 lenses IIRC & they appear frequently in university surplus sale barns. I suspect such lenses are pretty good.

Many universities, esp public ones, must sell their surplus items through an open process or they can get into big accounting trouble. Selling is safer & financially cleaner than junking in many circumstances.

ISU has a weekly sale of used computers, video cameras, spectrophotometers. vacuum systems, you name it. There's occasionally some 19th century optics stuff from the physics department. Yum!
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