adapter for Nikon lenses

Rob deJong · May 30th, 2009, 11:07 PM

Find Macro Extension Tube Canon 450D 400D 350D 40D 1000D AU on eBay Global Buying, with worldwide deals on items in all your top categories

I want to order some parts, but do not know exactly what. The main issue that I need to solve is the connection between extension tubes and spacer/step up rings. So there should be a thread on the extension tubes. I don't want to glue things. Does above item has such threads? Where could I find Nikon extension tubes with a thread.

Rob deJong · May 31st, 2009, 12:04 AM

Quote:

Originally Posted by Bob Hart

Rob.

You can shoot aerial image through Nikons by taking the groundglass out of 35mm adaptors but you give yourself a big problem with vignette on wide lenses and the telephoto lenses, which leaves you with about the same range of views that your camera's own lens can provide and a softer image.

Could you explain why you get problems with vignette WITHOUT a gg and not WITH a gg in the adapter?

Rob deJong · May 31st, 2009, 10:32 PM

Quote:

Originally Posted by Kin Lau

Rob,

A DOF adapter is not really what you want, with or without the GG.

Trying to shoot thru an SLR lens won't work either. Try this to convince yourself, mount the lens on a tripod and focus on a distant object. Now simply try to look thru the lens and see if you get clear image or not - you won't unless you're about 1 foot away. Try it with your camcorder as well.

Why DOES this (shoot through SLR lens) work in a 35 mm adapter WITH gg and NOT in a 35 mm adapter WITHOUT groundglass?

Kin Lau · June 1st, 2009, 02:10 PM

Quote:

Originally Posted by Rob deJong

Why DOES this (shoot through SLR lens) work in a 35 mm adapter WITH gg and NOT in a 35 mm adapter WITHOUT groundglass?

A 35mm lens casts an image circle much too large for the human eye or a small-sensor camcorder to use. A piece of GG basically _becomes_ the image, which your eye/camcorder can focus on.

Otherwise, you can do as Bob suggests, using an 10x macro lens to serve as a kind of "eyepiece", or get a proper eyepiece.

Rob deJong · June 7th, 2009, 11:27 PM

Quote:

Originally Posted by Kin Lau

A 35mm lens casts an image circle much too large for the human eye or a small-sensor camcorder to use. A piece of GG basically _becomes_ the image, which your eye/camcorder can focus on.

Otherwise, you can do as Bob suggests, using an 10x macro lens to serve as a kind of "eyepiece", or get a proper eyepiece.

I thought that a DOF adapter also needs app 7+ or 10+ dioptre to focus on the gg.
But then, what is the difference between a DOF adapter and an adapter as I want it (beside leaving away the gg).

Or what is (in terms of lens-optics) the difference between a real image and an aerial image?

Bob Hart · June 8th, 2009, 04:04 AM

Rob

"I thought that a DOF adapter also needs app 7+ or 10+ dioptre to focus on the gg."

Yes. That is the case. Like all good rules there are exceptions. There are apparently one or two little handycams with a macro function that can zoom in and focus close enough to do the job without a close-up lens or achromatic dioptre.

"But then, what is the difference between a DOF adapter and an adapter as I want it (beside leaving away the gg)."

Pretty much no difference except no motor no batteries and no groundglass, so it should be a much easier build, just threaded extension tubes, an achromatic dioptre small enough to fit inside the tube or of matching thread diameter on front for the end of a tube or step up adaptor to make it fit and likewise for the rear tube which mates up to the camera.

"Or what is (in terms of lens-optics) the difference between a real image and an aerial image?"

Your "real" image is - Subject >> Lens >> Image Projected On Groundglass >> Achromatic Dioptre >> Camera = an instantaneous "picture of a picture".

Aerial image is Subject >> Lens >> directly through a common point of focus >> Achromatic Dioptre >> Camera.

A beneficial collatoral effect of using the aerial image is that your autofocus works in many instances, great for tracking aircraft in flight as long as an insect does not fly across close in front, then the autofocus crashes to the nearest object, dust or fingermarks on the glass on back of the Nikon lens.

You set your NIkon lens to infinity focus or known distance, then manually focus your camera until you have the image sharp, the ride the autofocus switch in bursts when tracking objects moving towards or away from you.

Great trick if there is nothing in the foreground. Your hovering hawk would be easy to hold focus on. You might get a bit of hunt from head to tail but that would be about it on a Sony Z1.

The groundglass is a physical barrier to the aerial image and fixes the focal point for both Nikon lens and camera. Because this barrier is missing, the common point of focus for the aerial image can be allowed to float a little bit forward or backwards but outside a smaller range, sooner or later some defects occur, usually soft edges - sort of lensbaby on the cheap if you want to creatively restate the effect.

Kin Lau · June 8th, 2009, 02:49 PM

Quote:

Originally Posted by Rob deJong

I thought that a DOF adapter also needs app 7+ or 10+ dioptre to focus on the gg.

My Canon HF100 and Panasonic PV-DV53 can both focus on the GG w/o a diopter.

Rob deJong · June 17th, 2009, 02:03 AM

What if I buy:

Opteka 52mm 10x HD² Professional Macro Lens for Nikon: Amazon.co.uk: Electronics & Photo

as a macrolens in the adapter. Would that decrease image quality very much?

Bruce Foreman · June 17th, 2009, 06:40 PM

Rob,

For what you want to do you would be better off to purchase one of the DSLR's that do HD video. That way you would be able to use the same telephoto lenses you would to simply get digital photos of your birds.

The Canon 5D MkII owners can now download a firmware update that enables manual setting of aperture, shutter, and ISO.

I don't know if such an update will be forthcoming for the Canon T1i (I just bought one hoping an update will be in the works) however for what you want to do even full auto in the video will still work for you. Or you can do what many are starting to do with this T1i, purchase a Nikon lens to Canon EOS adapter and start looking for older manual Nikon lenses. Since there is no auto control link the camera cannot set aperture and autofocus won't work either so you simply set desired aperture on the lens, the cam sets ISO and shutter and you manual focus.

Since my primary "want" is for shallow DOF and selective focus in some shots, I have the inexpensive mount adapter coming and a 50mm f1.8 AI Nikkor (Mint!) is already here.

For your primary need something like the Canon T1i (set in 1280x720 30fps) with the 55-250mm lens (multiply by 1.6 to get 35mm frame equivalent), or one of the longer ones would work very well.

I use the Hoodman Hoodloupe 3.0 held on over the LCD with rubber bands as an EVF eyepiece. This setup will be far easier to manage, aim, focus, and use than trying to use an HV with 35mm camera lens adapted. Image quality will be a lot sharper, too.

Rob deJong · June 17th, 2009, 11:26 PM

Bruce,
I think you are right, but there are things preventing me from buying a HDSLR.

1 I fear the shallow depth of field. I am doing a lot of insects in close-up and birds in tele. DOF will be unworkable.
2 I want to continue to work in 50i. None of the present DSLR's has it. Its al progressive. I would accept 50p, but that is not possible in full HD 1920 * 1080, only in a lower resolution.
I want to combine the footage from apotential HDSLR with that from my HV20. And 24p in a nature film is not OK.

Thanks for your recommendations anyway. I think I have to wait for a camera that does the full HD in an appropriate frame rate.

Rob

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May 30th, 2009, 11:07 PM	#16
Rob deJong Regular Crew Join Date: May 2009 Location: Saly Hungary Posts: 169	Find Macro Extension Tube Canon 450D 400D 350D 40D 1000D AU on eBay Global Buying, with worldwide deals on items in all your top categories I want to order some parts, but do not know exactly what. The main issue that I need to solve is the connection between extension tubes and spacer/step up rings. So there should be a thread on the extension tubes. I don't want to glue things. Does above item has such threads? Where could I find Nikon extension tubes with a thread.

June 8th, 2009, 04:04 AM	#21
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	Rob "I thought that a DOF adapter also needs app 7+ or 10+ dioptre to focus on the gg." Yes. That is the case. Like all good rules there are exceptions. There are apparently one or two little handycams with a macro function that can zoom in and focus close enough to do the job without a close-up lens or achromatic dioptre. "But then, what is the difference between a DOF adapter and an adapter as I want it (beside leaving away the gg)." Pretty much no difference except no motor no batteries and no groundglass, so it should be a much easier build, just threaded extension tubes, an achromatic dioptre small enough to fit inside the tube or of matching thread diameter on front for the end of a tube or step up adaptor to make it fit and likewise for the rear tube which mates up to the camera. "Or what is (in terms of lens-optics) the difference between a real image and an aerial image?" Your "real" image is - Subject >> Lens >> Image Projected On Groundglass >> Achromatic Dioptre >> Camera = an instantaneous "picture of a picture". Aerial image is Subject >> Lens >> directly through a common point of focus >> Achromatic Dioptre >> Camera. A beneficial collatoral effect of using the aerial image is that your autofocus works in many instances, great for tracking aircraft in flight as long as an insect does not fly across close in front, then the autofocus crashes to the nearest object, dust or fingermarks on the glass on back of the Nikon lens. You set your NIkon lens to infinity focus or known distance, then manually focus your camera until you have the image sharp, the ride the autofocus switch in bursts when tracking objects moving towards or away from you. Great trick if there is nothing in the foreground. Your hovering hawk would be easy to hold focus on. You might get a bit of hunt from head to tail but that would be about it on a Sony Z1. The groundglass is a physical barrier to the aerial image and fixes the focal point for both Nikon lens and camera. Because this barrier is missing, the common point of focus for the aerial image can be allowed to float a little bit forward or backwards but outside a smaller range, sooner or later some defects occur, usually soft edges - sort of lensbaby on the cheap if you want to creatively restate the effect.

June 17th, 2009, 02:03 AM	#23
Rob deJong Regular Crew Join Date: May 2009 Location: Saly Hungary Posts: 169	What if I buy: Opteka 52mm 10x HD² Professional Macro Lens for Nikon: Amazon.co.uk: Electronics & Photo as a macrolens in the adapter. Would that decrease image quality very much?

June 17th, 2009, 06:40 PM	#24
Bruce Foreman Trustee Join Date: Nov 2006 Location: San Angelo Texas Posts: 1,518	Rob, For what you want to do you would be better off to purchase one of the DSLR's that do HD video. That way you would be able to use the same telephoto lenses you would to simply get digital photos of your birds. The Canon 5D MkII owners can now download a firmware update that enables manual setting of aperture, shutter, and ISO. I don't know if such an update will be forthcoming for the Canon T1i (I just bought one hoping an update will be in the works) however for what you want to do even full auto in the video will still work for you. Or you can do what many are starting to do with this T1i, purchase a Nikon lens to Canon EOS adapter and start looking for older manual Nikon lenses. Since there is no auto control link the camera cannot set aperture and autofocus won't work either so you simply set desired aperture on the lens, the cam sets ISO and shutter and you manual focus. Since my primary "want" is for shallow DOF and selective focus in some shots, I have the inexpensive mount adapter coming and a 50mm f1.8 AI Nikkor (Mint!) is already here. For your primary need something like the Canon T1i (set in 1280x720 30fps) with the 55-250mm lens (multiply by 1.6 to get 35mm frame equivalent), or one of the longer ones would work very well. I use the Hoodman Hoodloupe 3.0 held on over the LCD with rubber bands as an EVF eyepiece. This setup will be far easier to manage, aim, focus, and use than trying to use an HV with 35mm camera lens adapted. Image quality will be a lot sharper, too.

June 17th, 2009, 11:26 PM	#25
Rob deJong Regular Crew Join Date: May 2009 Location: Saly Hungary Posts: 169	Bruce, I think you are right, but there are things preventing me from buying a HDSLR. 1 I fear the shallow depth of field. I am doing a lot of insects in close-up and birds in tele. DOF will be unworkable. 2 I want to continue to work in 50i. None of the present DSLR's has it. Its al progressive. I would accept 50p, but that is not possible in full HD 1920 * 1080, only in a lower resolution. I want to combine the footage from apotential HDSLR with that from my HV20. And 24p in a nature film is not OK. Thanks for your recommendations anyway. I think I have to wait for a camera that does the full HD in an appropriate frame rate. Rob