Camera > Bellows > C-Mount-to-23mm adaptor?

[shawngibson]

Hi guys,

I got my camera (Sony A7II w/ Metabones Canon adaptor) but I've come to the conclusion that it is way out of my price range right now to buy a proper adaptor to hook it up to the scopes.

If I bought a Canon bellows, and a Canon-to-23mm adaptor (like this: http://www.ebay.com/itm/HOT-Canon-EOS-T ... SwDNdV0-w7) would I be able to use this to connect the camera to the microscope and utilize the full-frame?

Merci:)
Shawn

[shawngibson]

Does this make sense? The Omax part is from this, which I own: http://www.microscopenet.com/omax-140mp ... 10003.html

[apochronaut]

You've bought a fairly expensive camera , that can capture images as good as the microscope and tube lens can produce. I'm pretty sure the Omax lens will produce curvature of field and chromatic aberration at the edges , if you push it to put out a full frame image.I think what you need is something like a Raynox or other process type lens. Check the info here on setting up a camera system http://www.photomacrography.net/.

[shawngibson]

Thanks Apo, as always:)

I realize I need to upgrade a lot of my system, but it's going to happen over time, as I save. I'm already in over my head lol...

Field curvature means a not-rectangular image, I think (e.g. fisheye vs. rectilinear)? I know from stitching images that sometimes I get a crazy shape, and need to fix it in Photoshop. It works well if I don't need to push it around a lot, but fails miserably if I do need to (i.e. circle to rectangle).

I can deal with CA to an extent in Photoshop, as well.

I went to your link, but it's the homepage. I also went to Raynox (http://www.raynox.co.jp/english/egindex.htm) but have no idea what I'm looking for.

I simply don't understand what I'm supposed to be doing here.

At the exit point of the microscope (the 23mm hole) I need to have a lens which flattens the field?

Somewhere along the line after the hole I need to magnify the image to fit a 35mm frame?

Am I supposed to focus the light within the hole-to-sensor area?

Clearly, I'm lost:(
Shawn

You've bought a fairly expensive camera , that can capture images as good as the microscope and tube lens can produce. I'm pretty sure the Omax lens will produce curvature of field and chromatic aberration at the edges , if you push it to put out a full frame image.I think what you need is something like a Raynox or other process type lens. Check the info here on setting up a camera system http://www.photomacrography.net/.

[shawngibson]

Anther thing, light falls off by inverse square proportion. So, if I'm barely getting enough light from condenser-to-USB sensor now (off-kilter dark, i.e. oblique), then by adding a longer path, I'm going to have insufficient light, no? I mean all else being equal (I can increase ISO or use a longer shutter time, of course).

[apochronaut]

Here's a better link to Charles Krebs thread, that a lot of people have used as a base line to work from http://www.photomacrography.net/forum/v ... c.php?t=12.
Curvature of field doesn't affect the shape of the field....getting a round field means you aren't getting full frame coverage . I never consider that too bad as long as it is close, because I like to see a microscope field. That is called vignetting to most photographers.
Curvature of field is when a photo relay lens doesn't yield a flat field, so that the corners are out of focus , distorted and usually as a result have chromatic aberration too. Larger lenses corrected for flatness of field such as photo enlarging lenses or photo lithography lenses or large format camera lenses can produce much flatter better corrected images. Often they need to be reversed for micrography. Other well corrected tube lenses made by most of the major companies are also well corrected for flatness of field but they often are dedicated to certain objective characterstiics. For this reason, getting some advice from people that have actually tried various options with a microscope such as yours would be prudent. I'm talking in reasoned generalities but can't help you with the specifics of matching a good photo relay lens to your microscopes optical peculiarities.
I recall a little about your microscope and it doesn't have plan objectives? or does it? If it is not a plan microscope, then some curvature of field is built into the optics. The way, that is normally accommodated for micrography, is to enlarge the image sufficiently with a relay or tube lens that only the interior portion of the microscope image , around 50% of the diameter is imaged on the film or sensor. You can get a fairly undistorted flat field but you lose a large portion of the original microscope field. To get right out to the corners of the microscope field , full frame coverage , with a flat well corrected image, you generally need plan objectives and a good flat well corrected tube lens.

[apochronaut]

I believe you have a D.I.N. microscope, don't you? The oil immersion objective would be close to 45mm long in this case.

[shawngibson]

Thanks Apo, that link looks like it will be very helpful. You are correct, the current objectives aren't Plan, but I'll be upgrading to Plan achromatics very soon (link: http://www.microscopenet.com/plan-achro ... p-316.html). Certainly not going to be Zeiss or Nikon quality, I'm sure, but I suspect (or at least hope) they will 'up my game' by a noticeable amount.

Then I'll be upgrading the compound to a trinoc. with Kohler illumination in a few months (and will transfer over the Plan objectives to the new scope).

>>getting some advice from people that have actually tried various options with a microscope such as yours would be prudent

That might be a challenge since I'm guessing people with cheap microscopes like mine don't spend decent money on an optical path for high quality photographs.

Time to read the link you included:)

Thanks again for your help,
Shawn

Here's a better link to Charles Krebs thread, that a lot of people have used as a base line to work from http://www.photomacrography.net/forum/v ... c.php?t=12.
Curvature of field doesn't affect the shape of the field....getting a round field means you aren't getting full frame coverage . I never consider that too bad as long as it is close, because I like to see a microscope field. That is called vignetting to most photographers.
Curvature of field is when a photo relay lens doesn't yield a flat field, so that the corners are out of focus , distorted and usually as a result have chromatic aberration too. Larger lenses corrected for flatness of field such as photo enlarging lenses or photo lithography lenses or large format camera lenses can produce much flatter better corrected images. Often they need to be reversed for micrography. Other well corrected tube lenses made by most of the major companies are also well corrected for flatness of field but they often are dedicated to certain objective characterstiics. For this reason, getting some advice from people that have actually tried various options with a microscope such as yours would be prudent. I'm talking in reasoned generalities but can't help you with the specifics of matching a good photo relay lens to your microscopes optical peculiarities.
I recall a little about your microscope and it doesn't have plan objectives? or does it? If it is not a plan microscope, then some curvature of field is built into the optics. The way, that is normally accommodated for micrography, is to enlarge the image sufficiently with a relay or tube lens that only the interior portion of the microscope image , around 50% of the diameter is imaged on the film or sensor. You can get a fairly undistorted flat field but you lose a large portion of the original microscope field. To get right out to the corners of the microscope field , full frame coverage , with a flat well corrected image, you generally need plan objectives and a good flat well corrected tube lens.

[shawngibson]

Unfortunately the link where Charles Krebs explains his setup is dead:(

edit: Googling brought me to this:

http://www.krebsmicro.com/microsetup2/index.html

Yay:)

[shawngibson]

I believe you have a D.I.N. microscope, don't you? The oil immersion objective would be close to 45mm long in this case.

Yes, it's DIN.

Near as I can tell, a copy stand, bellows, and I'm still trying to figure out what exactly the ocular piece in the 23mm hole is...

I find this all very confusing lol

edit: and I suspect I'll need to rig up my gooseneck lights somehow under the condenser to get adequate light. This is going to be a fun, if frustrating, process.

[shawngibson]

Is this what you mean, Apo?

http://www.lmscope.com/produkt22/lmscop ... al+Adapter

It is 0.5x for 23mm - which is the same as the piece at the end of my Omax USB camera. So what would the difference be, other than higher quality?

[charlie]

Is this what you mean, Apo?

omg I hope not - that is expensive! I am hoping that you sort this out Shawn. It isn't easy figuring out a microphotography setup. (Regarding buying the generic plan objectives, I am seeing name brand plan objectives and even the occasional Neofluar on ebay for less than the $75 per objective that the set you linked costs.)