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02-05-2011, 02:43 PM   #1
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Possible to make a tilt shift lens out of a 50mm on a crop sensor?

I am looking to pick up another 50mm(Probably a f2 or f1.7 M) or a 55mm 2.0 and was wondering if anyone ever attempted to make one out of these?

I wanted to make a bendy cam one that I saw on this site.

Idea: Tilt-shift: Building a DIY tilt-shift lens

How to: Tilt-shift: Building a DIY tilt-shift lens

Anyone here ever try it on these lenses?


Last edited by Abstract; 02-05-2011 at 03:29 PM.
02-05-2011, 10:16 PM   #2
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It's an interesting idea. Much like the Lensbaby I have, but with better optics. I don't have a broken lens right now, and don't want to tear one apart. But I think I'm going to find a cheap one to try this out.
If you do this, be sure to post some photos of the final product, and images from it...

Tony
02-06-2011, 12:13 AM   #3
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That I will, yeah I looked at lensbaby but I figured this would make a better lens in general, I don't mind tearing one apart, 50mm 2.0's go for a cheap price after all. This type of lens always interested me, think its about time for me to try to make one.
02-06-2011, 02:13 AM   #4
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One need not rip-apart a SLR lens. The magic words: enlarger lens. No focusing helicoid to discard, no rear elements to deal with.

Or if you MUST destroy something, think: compact rangefinder. Decent fast 40-50mm Rokkors, Yashinons, Fujinons etc can be pulled from junked bodies, the sort that sell for US$10 per boxload on eBay. Or see what's at your local thrift shop.

02-06-2011, 03:10 AM   #5
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There's a thread somewhere on the forum from a guy who turned a 50mm lens (Olympus or Minolta if I recall correctly) into a shift lens with decent results. It helped that his lens of choice had a thick mount (giving some room to play with flange-focal distance and movements once it was removed) and a small rear element that didn't interfere with the mount on the body.

I think that a 35mm rangefinder lens would be a poor choice if you want anywhere close to infinity focus on a Pentax body. Most rangefinders have a very short distance from the rear element to the film plane.

A medium format slr lens would give you all sorts of room to build a mount with movements, which is pretty much the idea behind the the Arax, Arsat and Hartblei tilt and shift adaptors and their tilt/shift lenses for 35mm cameras
02-06-2011, 06:53 AM   #6
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I was thinking of using my enlarger lens also. I read where someone had been using one on bellows for macro work and thought about trying that also. I'd have one lens with three uses then.
02-06-2011, 12:40 PM   #7
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Enlarger lens is a great idea, but you will need a focal length longer than 50mm and the longer ones are generally not cheap.


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02-06-2011, 08:26 PM   #8
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QuoteOriginally posted by stevebrot Quote
Enlarger lens is a great idea, but you will need a focal length longer than 50mm and the longer ones are generally not cheap.
I've bought a number of enlarger lenses lately, and I must disagree. 35mm EL's are rare and expensive (US$150+); my 50's and 90's were cheap (US$5-9); my 75's were dirt cheap (US$1-5). My most expensive EL's are 100-105mm (US$20-25); my 140mm and 162mm were in the cheap range (US$5-9). EL-Nikkors and some other name brands attract premium prices, but most don't. Search eBay for LENS ENLARG* and see what pops up, eh?

For a bendycam using a 50mm EL or the glass ripped from a 135/FF rangefinder, keep the fitting short. But note that 50mm EL's are mainly intended for enlarging 35mm negs, while 75's and longer are designed for larger MF negs and so will have larger image circles, which is better for extreme bends.

02-07-2011, 06:06 AM   #9
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The first big problem* with DIY tilt lenses is establishing enough clearance to squeeze in a tilt mechanism.

A 75mm enlarger lens focused at infinity physically sits about 75mm from the sensor. For a K-mount camera this typically leaves more than 25mm clear for the tilting mechanism which may be sufficient (there is 45.46mm between the flange and the sensor on a K-mount). Medium format lenses typically expect a flange to sensor distance of 74-85mm which also leaves enough space to squeeze in a tilt mechanism on a K-mount camera.

See: http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

The possibility of disassembling a K-mount lens sufficiently to squeeze in a tilt mechanism depends on the details of the particular lens' construction, however for lenses that are 50mm or shorter focal length the chances of gaining much clearance by dis-assembly are not too good. That's because such lenses' rear glass element is typically near the end of the lens barrel (a 50mm lens is 50mm from the sensor when focused at infinity.)

Here's a photo of a dis-assembled pentax 50:1.2. I can imagine clamping the lens inside a short rubber tube over the silver threaded portion but I don't see how to get focus adjustment. Maybe one could shorten the focusing ring and re-use it between the rubber tube and the lens?


See: https://www.pentaxforums.com/forums/general-technical-troubleshooting/132166-...y-k50-2-a.html

I had moderate success in making DIY tilt-shift lenses, but never made one good enough for routine use because it is difficult to focus a lens on a rubber tube and hold it in exactly the right position.

I wound up buying a Hartblei adapter and a Pentacon Six lens on ebay for about $200 total.

Dave

*another big problem is building a mechanism to adjust and hold the lens' position. The best approach I found to solve that problem was to secure the lens with a lever between it and the camera's tripod mount.

Last edited by newarts; 02-07-2011 at 06:28 AM.
02-07-2011, 03:32 PM   #10
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Man seems like I really need to research this a bunch...Thanks for all the info...Hmmm.

The guy in the article is using a fairly small 28mm Minolta lens, I wonder if I should just search the one he used out and that would simplify the process.....hmmm.....I mean I can use that on a Pentax I presume since its the cap thats connecting....
02-07-2011, 03:47 PM   #11
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QuoteOriginally posted by Abstract Quote
Man seems like I really need to research this a bunch...Thanks for all the info...Hmmm.

The guy in the article is using a fairly small 28mm Minolta lens, I wonder if I should just search the one he used out and that would simplify the process.....hmmm.....I mean I can use that on a Pentax I presume since its the cap thats connecting....
The important parameter is the distance from the lens to the sensor and finding a way to hold that distance while tilting the lens. A wide angle lens like a 28mm has a telephoto group behind it that in effect projects the 28mm image onto the sensor. You'll find that there's likely a lens element right where the 28mm lens meets the camera.... that's ok, but you'll be faced with a situation much like that shown in the disassembled lens above.

But maybe there's something about the construction of the 28mm lens used in the article that makes it easy to adapt.

In general, longer focal length lenses are easier to convert to tilt-shift because the actual glass lenses inside them don't have to be close to the camera.
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