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03-02-2010, 09:26 PM   #1
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Tilt - shift

I would just like to know,

Does a tilt, or shift, or tilt - shift adaptor have a lens in it ?

Chromo

03-02-2010, 09:42 PM   #2
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Typically, no.

If it is an adapter for Pentax K-mount, it is probably meant for adapting a medium-format lens (with an image-circle big enough to be tilted or shifted) onto a 35mm frame, ignoring the fact that modern Pentax sensors are less than 35mm. I have one of each from Hartblei, and there is no glass.

Now, if it is a "tilt-shift lens" then it will obviously have the glass bits!
03-02-2010, 09:48 PM   #3
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Hmmm.
I thought of making one but better to get the impossible bits out of the way first !

Sooo, can you use standard lenses on them ?
03-02-2010, 09:57 PM   #4
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QuoteOriginally posted by chromo Quote
Hmmm.
I thought of making one but better to get the impossible bits out of the way first !

Sooo, can you use standard lenses on them ?
Hey, why not? You'll get some vignetting where the image circle ends, but that doesn't need to be a showstopper. If you're using an APS-C sensor camera, you could tilt or shift a 35mm lens to some degree.

Of course, you also might be surprised at just how cheap medium-format lenses are these days...

03-03-2010, 05:46 AM   #5
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Well let me see now.....hmmm......If my lens is mounted say 20mm further away from the sensor, then the image will be larger, right ?

I'll have to start on drawings cos I'll be going for aluminium and brass not rubber toilet plungers like I've seen others use. I have a lathe and mill and so on.

And unlike manufactured adaptors I've seen so far, I would have thought that the pivot point for the tilt should be the centre of the sensor, not the centre of the adaptor. Am I right here ?

Will make an interesting project.

Chromo.
03-03-2010, 05:59 AM   #6
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QuoteOriginally posted by chromo Quote
Well let me see now.....hmmm......If my lens is mounted say 20mm further away from the sensor, then the image will be larger, right ?
I don't think that necessarily follows; In my experience a backwards 135:2.5 Takumar lens may have a smaller useful image circle than when it is mounted normally.

QuoteQuote:
I'll have to start on drawings cos I'll be going for aluminium and brass not rubber toilet plungers like I've seen others use. I have a lathe and mill and so on.

And unlike manufactured adaptors I've seen so far, I would have thought that the pivot point for the tilt should be the centre of the sensor, not the centre of the adaptor. Am I right here ?
I think you are correct.

You might consider an enlarger lens; they have an Iris diaphram but no focusing helicoid; however you can focus using your bellows. Enlarger lenses made for 6cm film have a large, flat image circle, and are relatively inexpensive.

Dave
03-03-2010, 11:07 AM   #7
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QuoteOriginally posted by chromo Quote
Well let me see now.....hmmm......If my lens is mounted say 20mm further away from the sensor, then the image will be larger, right ?

I'll have to start on drawings cos I'll be going for aluminium and brass not rubber toilet plungers like I've seen others use. I have a lathe and mill and so on.

And unlike manufactured adaptors I've seen so far, I would have thought that the pivot point for the tilt should be the centre of the sensor, not the centre of the adaptor. Am I right here ?
How you want to build it and what kind of lens to use depends on what you want to do with your adapter: Macro or Landscape or Product shots, or just some funky looks like a Lensbaby?

I only have a rudimentary understanding of camera optics, but there are a couple of things about adapters that I do know (which includes putting tilt or shift in between the lens and your camera sensor/ film plane)

All camera lenses are designed and calibrated to project an image (in a circle) onto a plane at a prescribed distance, referred to as "flange focal distance" - see here for a list. If you exceed that distance, your lens (typically) loses the ability to focus on things further away. This is why it is easier to adapt a lens "down" the flange distance chart and retain all focus possibilities.

So, adapters that are not for a particular application (macro, lensbabies, etc.) almost always are built to fit *inside* the difference in flange distance between one type of lens or another (my MedFormat T/S adapters work well because the MF lens is designed to project a very big image circle (making it tiltable and shiftable) from the back of the lens to a "film plane" 74.1mm away, while my Pentax only requires 45.5mm distance... so that means my MF lensmount has to be 28.6mm further away from the front of the Pentax lensmount to focus the way it was designed (you lose focus-able distance as you exceed this difference). My adapters then fit their T/S mechanics into this 28.6mm distance!

You can make an adapter that makes the distance larger, but *without additional optics* you are limiting what you can do with the lens in terms of the focus it was designed for, etc. Sure, you can "adjust" the focus of any lens, but not enough to make up for gigantic differences in flange distance.

Make sense?

Again, I'm not an expert, but from my limited experience with view cameras (very limited) there is a *ton* of "slop" available here and experimentation is key. Or, as Newarts suggested, use a lens that isn't designed around a rigid focus distance, like an enlarger lens. Once you tilt and shift your lens, you'll just have to play with the movements (and focus distance, however you control it) to understand what is going on. I hope your camera has Live View or big viewfinder!

Last edited by panoguy; 03-03-2010 at 11:13 AM.
03-03-2010, 03:31 PM   #8
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Thanks Panoguy...Good information.


Last edited by chromo; 03-03-2010 at 03:36 PM.
03-04-2010, 12:17 PM   #9
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QuoteOriginally posted by chromo Quote
And unlike manufactured adaptors I've seen so far, I would have thought that the pivot point for the tilt should be the centre of the sensor, not the centre of the adaptor. Am I right here ?

Will make an interesting project.

Chromo.
Where the system tilts depends on what you are trying to do and what effect you want. A fully adjustable tilt system will usually allow tilt movements around both the centre of the lens and the sensor as in the case of my converted Ilford Monobar (have a look in https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/91033-tilt-shift-lens-club.html). There is a lot of information available about the defferences between lens and detector tilt but it is quite complicated and takes a lot of reading before it all makes complete sense (links to some sources I found particularly usefull are available in the tilt shift club). The basics of the two different tilt movements hopwever is that detector tilt is used to control the perspective and lens tilt is used to control the angle of the plane of focus but in practice both movements can affect both.
If you have machining facilities then you shouldn't have any problems putting together an accurate tilt shift adapter but if you intend to put a lot of effort into the adapter then if would be worth putting some effort into understanding how it should all work first.
As far as lenses go, medium or large format lenses will give you large image circles so you have plenty of available movement without vignetting and will also give a long registration distance so you have plenty of space for your adapter. However you will end up with a relatively long focal length and so a narrow field of view. On an APSC sensor you may well find that you have a reasonable amount of movement from a 35mm format slr lens but the registration distance will be very limited. Unless you are working on close subjects requireing close or macro focus you won't need all that much tilt movement for most subjects.
03-05-2010, 12:40 AM   #10
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I did a little with camera movements long ago, on a modified 9x12cm Graflex. There are good reasons why commercial small format (35mm/FF and APS-C) and even medium format (6x7cm and smaller) movement gear is rare.

* Larger formats offer lots of space for total flexability, total control of the movements -- rise and fall, shift, tilt, and swing -- of both the lens plane and film/sensor plane. Some extreme contortions REQUIRE all that space. Some images can be achieved no other way.
* Larger formats can handle many lens choices, to provide an image circle that will fill the film/sensor frame.
* And larger groundglass size (and hand magnifiers) let you closely examine just what your maneuvers are doing to the image.

Adapters for small format (35mm and APS-C) typically only move the lens plane, and only with tilt and shift, not rise-and-fall nor swing, and they can only T&S a little ways. So you lack many movements, and much range of motion. You have limited lens choices, especially at wider-than-normal angles. And it's pretty hard to see just what's sharp and what isn't, in the small viewfinders.

Here's an overview: Tilt-shift photography - Wikipedia, the free encyclopedia - Canon and Nikon make nice T&S lenses. Right. They're used in architectural photography, and some miniatures work, etc. If you get paid for shooting that stuff, that's the gear you'll use. Otherwise:

* You can easily build Lensbaby-type fittings, cheap, and get cute effects, rather lacking in fine control. Hey, fine control is much over-rated, and it's a real pain in the ass to achieve. Try working a view cam sometime, eh?
* You can buy a MF-to-PK T&S adapter, not so cheap, and face the lens limitations. Hey, limitations are GOOD for you! They build character, and inventiveness, and envy. (I never believed the line, THAT WHICH DOES NOT KILL US, MAKES US STRONGER. No, it only leaves us crippled and agonized. But I digress.)
* You can fake it, shoop it. But what's the fun there?

Anything else I say will just get stuff thrown at me, so I'll stop now.
03-05-2010, 06:21 AM   #11
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QuoteOriginally posted by RioRico Quote
... And larger groundglass size (and hand magnifiers) let you closely examine just what your maneuvers are doing to the image.... And it's pretty hard to see just what's sharp and what isn't, in the small viewfinders....
Its almost impossible to see what you are doing in the viewfinder but Live View is better than ground glass. You can zoom in without a magnifier and the image is bright enough that you don't need a black tent over your head to see it.
03-05-2010, 07:20 AM   #12
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coming back to your original question:
Most adapters do not have a lens in it, but the latest one from Hasselblad does. It is both a Teleconverter and a T/S adapter. The idea is great since you can still use standard lenses and the converter gives you enough distance from the camera to allow the T/S movement. Also the amount of T/s is amplified by the adapter. On the other hand you will not be able have a wide angle T/S.

If you want one for macro photography check this one out I made a while ago:

Pentax Hacks: Self-made tilt shift bellows
03-05-2010, 07:46 PM   #13
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I thought I might start with something like this. That way I'll get the male and the female mounts and put my T/S in between.

Extension Tube Macro Ring for Pentax / K-mount L8B - eBay, Camera Body Parts, Photographic Accessories, Cameras. (end time 21-Mar-10 20:59:10 AEDST)
03-05-2010, 09:13 PM   #14
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QuoteOriginally posted by chromo Quote
I thought I might start with something like this. That way I'll get the male and the female mounts and put my T/S in between.
I ordered two sets of these from someone in Hong Kong, was sent four sets instead! They're absolutely wizard for attaching strange optics to a camera. The mounts are endlessly useful, and the extra tubes are good for capturing spiders.
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