MicrobeHunter.com Microscopy Forum

While I review the many great shots are posted here, I am often wondering what power of objective was used to get them. Also knowing cameras, photo setup, speeds would be very helpful.

Thoughts?

Totally agree.

However, scale bars, which are pretty standard in any scientific illustration are a bit of a PITA to set-up and overlay in an image as are the imaging technical details. At the very least, magnification should be posted. Many images here, in my opinion, are useless without it. On occasion, I'm guilty of omitting this information which invariably makes me feel slightly soiled.

But then, many here are in it just for the pretty pictures

One of the reasons is due to the prevalence of telescopy as a springboard to microscopy. Such and such power is widely used in amateur telescopy where the magnification of the objective lens is not really given : just a focal length and magnification calculated mathematically. This used to be the case with microscopes but was altered to a more practical form by R.M.S. standards and the adoption of a standardized objective focal length. Unfortunately, when portraying images pictorially, the field of view can alter the apparent magnification. If the actual microscope field is presented, then if the f.o.v. is also presented in actual microns, then it becomes a slam dunk. When the image is cropped to an aspect ratio it isn't so easy but the measure across the field from corner to corner would help.
The standard has kind of become to identify the objective magnification and then look for cues as to what the field size is but identifying the field size up front would allow for a quick assessment by the viewer.
With a 20mm f.o.v. or f.n. , it is really easy. 2000 microns, 10X : 1000 microns, 20X : 500 microns, 40X : 200 microns , 100X. No scale bars are needed, just whether the image capture crosses the entire field , either as a circle or diagonally, corner to corner.
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Do you think having a standard size item (a hair) in the picture for scale would help?

Unfortunately a hair is quite large and would really only be useful as a scale device with a stereo microscope. In microscopy the level of detail and therefore information in just jumping from .65 N.A. to 1.25 N.A. is phenomenal, then utilizing that N.A. at high magnification reveals even more information. Knowing the field size that a photo covers is the best way of determining the size of objects and details

Thanks for the response..I considered my suggestion suboptimal but thought it would provoke a discussion.

Is there a common magnification of the optical path for photography? While one can assume common objectives of 4x, 10x, 40x and 100x, the remaining optics seem to up in the air.

How much technical knowledge do you need? Getting this information is sometimes a real challenge. We all know how these things generally look and how big they are. If size is a real surprise, maybe that should be noted. Most of us have been around microscopy for a while.

DonSchaeffer wrote: ↑

Tue Mar 21, 2023 10:29 pm

How much technical knowledge do you need? Getting this information is sometimes a real challenge. We all know how these things generally look and how big they are. If size is a real surprise, maybe that should be noted. Most of us have been around microscopy for a while.

I'm not sure what you are referring to here. If it is the differing field sizes, then those are entirely based on the f.n. of your eyepiece(s), which is published information or easy to obtain. It is no different than taking a stick you know to be 3 feet long and measuring a shoe with it.....well that's just under a third, so 11 inches. Offering up a magnification through a photo isn't that useful because screen sizes can vary do much. ......if a scale bar is not an option.

Scoper wrote: ↑

Mon Mar 20, 2023 10:09 pm

While I review the many great shots are posted here, I am often wondering what power of objective was used to get them. Also knowing cameras, photo setup, speeds would be very helpful.

Thoughts?

This thread seems to have turned into two discussions: 1) understanding what equipment was used to achieve the resulting image, and 2) providing accurate information about the size of an object or FOV.

The first topic is pretty simple, hopefully people include the equipment used when posting, either in the text describing the image or in their signature.

The second topic, as discussed, can be more work but can help with IDing organisms, sharing details about certain organisms, etc. As an example, I have 2 objective magnifications: 10x and 40x. I also can set my DSLR to 1.5x sensor crop mode, resulting in 4 total FOVs. Using a micrometer slide that cost a few dollars I measured the FOV for my 4 combinations and created simple scale bars as transparent PNG files as overlays. Even if images were later cropped and resized, as long as the correct scale bar is placed on the image before cropping, the bar will be accurate in measuring any object in the cropped FOV. Of course the FOV of this newly cropped image is unknown (unless the imager took great care to measure the crop) which is why scale bars can be much more useful.

If you don't plan on cropping, sharing the FOV from the micrometer measurement in the photo's description is enough to tell the viewer how large an object is.

Repeating what macnmotion and others have said, scale bars are very useful. They are independent of magnification and FOV - they simply give the viewer the size of objects in the image. Various methods for making scale bars were discussed here: https://www.microbehunter.com/microscop ... =27&t=6547

I just added a detailed method for Photoshop users to that thread.

Cheers, David

If you are looking for software to use for measuring and adding scale and text plus other things to your images you may want to try this freeware:- Micam at,
http://science4all.nl/?Microscopy_and_Photography


Used here to mark up and measure original pollen image image from camera and then combine into composite image with Photoshop

I tend to make a number of image and videos for my postings. The reason I do is that some features require a longer view than others. I have no way of determining exactly how many units long each of my views are and finding out with any accuracy is simply not worth the effort. The measurements I have made in the past are simply not worth the time it takes to make them.

DonSchaeffer wrote: ↑

Wed Mar 22, 2023 11:59 pm

I tend to make a number of image and videos for my postings. The reason I do is that some features require a longer view than others. I have no way of determining exactly how many units long each of my views are and finding out with any accuracy is simply not worth the effort. The measurements I have made in the past are simply not worth the time it takes to make them.

Really? How many combinations of objective+camera do you have?

I have 4 objectives, one camera. The magnifications are those commonly used, maximum somewhere around 1,000 x. In making my images, I switch objectives several times. My videos are continuous. I am grabbing images like a street photographer.

I do as many others, I take images of a stage micrometer with each objective and measure the distance (in pixels) of the markings and divide by the number of markings to get an average. The advice to make a few transparent png images of the scale bars is something I hadn't thought of, but it's a good one.

For me the problem is that I'm frequently using different microscopes and haven't used "my" microscope in probably a year as I have been trying to get all these extras cleaned up, tested, and out of my workspace. Slow but steady progress, now if I can just bring myself to give up the extra phase scopes too.

I think it's is useful to add technical data to the images/videos posted here. Magnification can be tricky though, since there are many factors involved. Listing the equipment used offers to the observer a general context.

I wouldn't go as far as saying that a picture or video shared without technical information is useless, especially if it is beautifully made or if it is showing some interesting specimen behaviors. This is an amateur microscopy forum, to each his own.