Looking to enter Micro

Starting out in microscopy? Post images and ask questions relating to the microscope and get answers from our more advanced users on the subject.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

MNBoldone
Posts: 25
Joined: Wed Mar 23, 2016 9:23 pm
Location: USA

Looking to enter Micro

Post by MNBoldone »

I have been looking to purchase a dissecting and a compound microscope for primarily plant and lichen examination, but I wanted to assure that I could also obtain good photographs of specimens as well. I would use a Canon 6D and/or a 7D (I already have both). I believe my principle interest would be rather low magnifications (4-20x).

I have a 100 mm macro lenses, but I do not have a rail - my macrophotography has all been in the field. But that is another matter.

Originally I was looking for a dissecting microscope that I could set up for photography; as well as, a compound microscope that I could set up for photography. After reading some material in these forums I am thinking that I may be better off using a compound microscope for all my microphotography and acquiring a less expensive dissecting microscope just for observation.

I am interested in any recommendations, at this point my principle question is would you recommend using a compound microscope over a dissecting scope for low magnification microphotography?
Brad B.

Charles Krebs
Posts: 5865
Joined: Tue Aug 01, 2006 8:02 pm
Location: Issaquah, WA USA
Contact:

Post by Charles Krebs »

The "best" answer will depend on your image requirements and desired work flow.

The vast majority of stereo scopes are a compromise in that they are designed primarily for viewing. In order to get comfortable viewing they need sufficient depth-of-field and relatively long working distances. This is obtained by using a modest (low) numerical aperture. But the numerical aperture is what determines your highest possible resolution.
Low NA -> larger DOF -> lower resolution
High NA -> low DOF -> higher resolution

Generally speaking the objectives on a compound microscope are designed more with resolution in mind rather than DOF. As a result they can (usually) provide much greater resolution on a subject, but with very little DOF. If you are working with 3-dimensional subjects (or for that matter any subject with discernible depth) you will very likely find it necessary to use image stacking to create a satisfactory photograph.

For example, typical objective NA's for a compound scope are as follows:

4-5X NA 0.1-0.15
10X NA 0.25 - 0.30
20X NA 0.40

Many stereo scopes (even from high quality manufacturers) will have a maximum NA of about .09 - 0.1. There are certainly some exceptions, but you would want to search out the specifications, and be aware that stereo scopes (or macroscopes) with significantly higher numerical apertures can carry very high price tags.

There are also other considerations, for example working distance can be needed for subject manipulation and lighting.

So it is easy to make a good case for having both a stereo and a "compound" microscope.

If you are interested in the 4x-20X range for both viewing and photography, and will use only one piece of equipment then either a high end, high NA stereo (macroscope) could work out OK, or you could choose a compound scope with selected higher working distance objectives.

MNBoldone
Posts: 25
Joined: Wed Mar 23, 2016 9:23 pm
Location: USA

Thank you Charles

Post by MNBoldone »

Most of my viewing use would be a stereo scope, but a compound scope would be required for spore work. Thus I would plan to obtain both microscope styles.

I assumed I would have to image stack to get anything better than documentation photos through a compound microscope.

I had been looking at trinocular SZ4045 and trinocular BH2 scopes on ebay for almost a year. I have been pretty tentative due to perhaps an overabundance of caution and a lack of value knowledge and technical knowledge. I have also been pretty cautious because the apparent difficulty in finding NFK eyepieces and other connecting parts (i.e. PA1-10A). My recent thinking was that if I limit my photography to the compound scope, I could relatively and quickly easily purchase a binocular stereo scope so I could do non-photography work.

I will continue to look for trinocular versions of both.

Thank you. I really appreciate your taking time to post here, as well as, your articles. They have been very helpful to me.
Brad B.

Post Reply Previous topicNext topic