DIY infrared conversion, technical questions

[Badrmino]

I have some questions regarding ir convertion

I borrowed a Nikon d70 converted camera from a friend and I really like what I could do with it. See attached photos (edited)

Since I decided to convert one but first played with a couple of point and shoot old cameras that I happen to have.

I successfully managed to remove the ir filter, so changed them to full spectrum, however, both couldn't autofocus accurately on medium and infinity distances

This is, I am assuming because I haven't replaced the filter with a glass( in the case of full spectrum) or an ir(eg. 720nm filter) as a result of diffraction?

Now my question is how to cut the replacement precisely? A glass cutter? Does the thickness matter a lot,? If say there is a 0.5mm difference?

What If I put the filter in front of the lens instead of sensor?

Has anyone tried reversing (instead of removing it).

I am sure some of these questions are silly but couldn't find answers on the web

Thanks in advance

Badr


Nikon d70


Nikon d70

 

[Bodkins Best Photography]

I have some questions regarding ir convertion

I borrowed a Nikon d70 converted camera from a friend and I really like what I could do with it. See attached photos (edited)

Since I decided to convert one but first played with a couple of point and shoot old cameras that I happen to have.

I successfully managed to remove the ir filter, so changed them to full spectrum, however, both couldn't autofocus accurately on medium and infinity distances

I suggest you give this a read. https://www.lifepixel.com/introduction It explains issue with focus after conversion which particularly effects DSLRs. After converting a dslr you will face issues with focus on certain lenses. Mirrorless cameras are immune to the focusing issues.

tldr; Mirrorless Camera Calibration
Because of their unique design these cameras stand apart in their ease of use both as IR only and as full spectrum converted cameras. Since they are mirrorless they rely completely on the imaging sensor for all aspects of the image capture process, including focus and metering. Because of this they are able to “see” the IR focus shift real time and adjust for this on the fly while focusing. This allows you the freedom to use pretty much any micro four thirds lens and still achieve sharp images. All mirrorless cameras like the Panasonic Lumix G series, Olympus PEN series, Sony NEX/A series, etc are all calibrated specifically to take advantage of this unique capability. Therefore there is no need to have any focus calibration options or to send us a lens when you order a mirrorless camera conversion service.

 

[JimH123]

I have some questions regarding ir convertion

I borrowed a Nikon d70 converted camera from a friend and I really like what I could do with it. See attached photos (edited)

Since I decided to convert one but first played with a couple of point and shoot old cameras that I happen to have.

I successfully managed to remove the ir filter, so changed them to full spectrum, however, both couldn't autofocus accurately on medium and infinity distances

This is, I am assuming because I haven't replaced the filter with a glass( in the case of full spectrum) or an ir(eg. 720nm filter) as a result of diffraction?

Now my question is how to cut the replacement precisely? A glass cutter? Does the thickness matter a lot,? If say there is a 0.5mm difference?

What If I put the filter in front of the lens instead of sensor?

Has anyone tried reversing (instead of removing it).

I am sure some of these questions are silly but couldn't find answers on the web

Thanks in advance

Badr


Nikon d70


Nikon d70

Concerns me that you have lost medium and distant focus. Since you said Point and Shoot, I am assuming that this is mirrorless since that is the only kind of Point and Shoot that I know of.

This tells me that the objective lens is not getting close enough to the sensor. Does the lens seem to have proper movement with it moving in and out as far as you remember it? Depending upon the zoom range and FL of the camera, the lens travel can range from just a short distance to a much longer distance.

I also assume that when you removed the UV-IR cut filter out, that you probably did not replace it with a piece of blank glass of the same thickness. I am not quite sure the effect on focusing when that thickness of glass is not present. Maybe it could have an effect on focus. I'm not quite sure.

 

[john isaacs]

I converted a Panasonic TZ5 by just removing the filter. I put a 720mm filter on it, and it focused just fine at any distance.

 

[MCLV]

I have some questions regarding ir convertion

I borrowed a Nikon d70 converted camera from a friend and I really like what I could do with it. See attached photos (edited)

Since I decided to convert one but first played with a couple of point and shoot old cameras that I happen to have.

I successfully managed to remove the ir filter, so changed them to full spectrum, however, both couldn't autofocus accurately on medium and infinity distances

This is, I am assuming because I haven't replaced the filter with a glass( in the case of full spectrum) or an ir(eg. 720nm filter) as a result of diffraction?

Now my question is how to cut the replacement precisely? A glass cutter? Does the thickness matter a lot,? If say there is a 0.5mm difference?

What If I put the filter in front of the lens instead of sensor?

Has anyone tried reversing (instead of removing it).

I am sure some of these questions are silly but couldn't find answers on the web

Thanks in advance

Badr


Nikon d70


Nikon d70

Concerns me that you have lost medium and distant focus. Since you said Point and Shoot, I am assuming that this is mirrorless since that is the only kind of Point and Shoot that I know of.

This tells me that the objective lens is not getting close enough to the sensor. Does the lens seem to have proper movement with it moving in and out as far as you remember it? Depending upon the zoom range and FL of the camera, the lens travel can range from just a short distance to a much longer distance.

I also assume that when you removed the UV-IR cut filter out, that you probably did not replace it with a piece of blank glass of the same thickness. I am not quite sure the effect on focusing when that thickness of glass is not present. Maybe it could have an effect on focus. I'm not quite sure.

Glass affects optical length (it shortens it compared to air by factor equal to refraction index). This can have two effects. Your camera becomes near-sighted if there is insufficient extra travel in focusing mechanism. And it can also break the alignment of PDAF module on DSLR cameras since paths to the imaging sensor and AF sensor are no longer the same.

 

[Badrmino]

Many thanks for the replies, very helpful.

I used a samsung digimax a7 which have an optical viewfinder so it may have 2 af modules, anyway it was just for the experience,

I have already bought a nikon d70 and will order a 720nm filter to cut to sensor size ready for replacement, at worse I can focus manually

Thanks again

 

[Badrmino]

I converted a Panasonic TZ5 by just removing the filter. I put a 720mm filter on it, and it focused just fine at any distance.

Thanks John

Did you mean you put it as a replacement or in front of camera?

 

[MCLV]

Many thanks for the replies, very helpful.

I used a samsung digimax a7 which have an optical viewfinder so it may have 2 af modules, anyway it was just for the experience,

I have already bought a nikon d70 and will order a 720nm filter to cut to sensor size ready for replacement, at worse I can focus manually

Thanks again

You need the correct glass thickness also for manual focusing using viewfinder. Otherwise, alignment of optical distances to the sensor and focusing screen will be also broken.

 

[JimH123]

Many thanks for the replies, very helpful.

I used a samsung digimax a7 which have an optical viewfinder so it may have 2 af modules, anyway it was just for the experience,

I have already bought a nikon d70 and will order a 720nm filter to cut to sensor size ready for replacement, at worse I can focus manually

Thanks again

You need the correct glass thickness also for manual focusing using viewfinder. Otherwise, alignment of optical distances to the sensor and focusing screen will be also broken.

This is one of the reasons to use a place that specializes in this conversion since they have access to blank glass of the correct thickness.