Choices: Size or Clarity

[JBW]

many have noted that my focus is not exactly focused of late. It seems that with the Celestron Digital Microscope choices must be made. Note the two shots the sharper is about 1/2 the size of the other. If I want better focus I shall have to choose 800 rather than 1600 on the long side.

[Round Tuit]

many have noted that my focus is not exactly focused of late. It seems that with the Celestron Digital Microscope choices must be made. Note the two shots the sharper is about 1/2 the size of the other. If I want better focus I shall have to choose 800 rather than 1600 on the long side.

Brian - This is true of any poorly focused photo. If you look at it at a smaller size, it will look sharper. This is the reason that photos almost always look sharp on the little lcd screen of the camera.

[JBW]

Brian - This is true of any poorly focused photo. If you look at it at a smaller size, it will look sharper. This is the reason that photos almost always look sharp on the little lcd screen of the camera.

that' true. I'm just wondering if my skills have deserted me or if I need to find ways to work around the limitations of a $129 digital camera microscope. Barring work arounds I hope people will cut me some slack on the focus and critique my composition artistic attempts.

[Manfred M]

Brian - I think the issue is more likely your choice of subject matter than the microscope you are using.

Many years ago when I did some photo-microscopy, I found that it was critical to use a subject that was very flat so that there was no significant impact of the shallow depth of field at the level of magnification I was using. I know a geologist who has some very nice rock images, but these were cut very thin and polished so that they photographed well using a microscope.

I suspect that your samples are simply not flat enough to photograph well.

[Stagecoach]

I'm just wondering if my skills have deserted me or if I need to find ways to work around the limitations of a $129 digital camera microscope

Brian, I don't think your skills have deserted you at all, but suspect it is purely the limitations of the scope.

A couple of threads ago I mentioned undertaking a simple test with something like a slightly tilted needle or wire that we know has a 'sharp' even edge and we can see exactly where the focus plane is. You can then determine from the results exactly what you can achieve IQ wise.

[Manfred M]

Brian, I don't think your skills have deserted you at all, but suspect it is purely the limitations of the scope.

A couple of threads ago I mentioned undertaking a simple test with something like a slightly tilted needle or wire that we know has a 'sharp' even edge and we can see exactly where the focus plane is. You can then determine from the results exactly what you can achieve IQ wise.

Good idea Grahame - shooting an image of a long, relatively flat object will quickly identify any inherent optical issues with the microscope.

[JBW]

Brian, I don't think your skills have deserted you at all, but suspect it is purely the limitations of the scope.

A couple of threads ago I mentioned undertaking a simple test with something like a slightly tilted needle or wire that we know has a 'sharp' even edge and we can see exactly where the focus plane is. You can then determine from the results exactly what you can achieve IQ wise.

I just happen to have some plastercine ready to hold a needle.

[JBW]

except for cropping it's SOOC
Celestron InfiniView ~ ISO 50 ~ Shutter Speed 1/65s ~ F/2.8 ~ Aperture Priority

[Stagecoach]

[IMG]
except for cropping it's SOOC
Celestron InfiniView ~ ISO 50 ~ Shutter Speed 1/65s ~ F/2.8 ~ Aperture Priority

Brian, out of interest how and where do you adjust ISO, Shutter speed and Aperture. I have the manual downloaded but I can't see any reference in there

Is this something that is done via your computer?

[JBW]

Brian, out of interest how and where do you adjust ISO, Shutter speed and Aperture. I have the manual downloaded but I can't see any reference in there

Is this something that is done via your computer?

As far as I am aware my only possible adjustment is the amount of light. FL is always 9mm and F/2.8 never changes. The ISO does vary.

[rudi]

Hi Brian,

IMO, the 'issue' you encounter with your microscoop is the extremely shallow DOF (fex DOF at magnification 5x , f2.8 is
+/- 0.025 mm) and vibration.
Stacking for more DOF with a sturdier set up is maybe the way to go.

HTH.

[Stagecoach]

As far as I am aware my only possible adjustment is the amount of light. FL is always 9mm and F/2.8 never changes. The ISO does vary.

Thanks for that Brian I had wondered if that was the case but interesting that the ISO and speed change.

[JBW]

Thanks for that Brian I had wondered if that was the case but interesting that the ISO and speed change.

the camera tells me it is running the AE program.

[DanK]

I haven't yet tried photomicrography--I'll have my introduction in a month--but I think Rudi hit the nail on the head. With a wide aperture and a high level of magnification, DOF has to be tiny. There are only two solutions. One is Manfred's: shooting objects that are very flat. The second is Rudi's: focus stacking.

I have no idea how one adjusts focus finely enough with your scope to be able to stack. That's one of the questions on my list for the experts who are going to introduce me to this next month. However, they work in a university lab with high-end equipment, so I don't know whether what they show me will be possible with your scope.

[JBW]

I haven't yet tried photomicrography--I'll have my introduction in a month--but I think Rudi hit the nail on the head. With a wide aperture and a high level of magnification, DOF has to be tiny. There are only two solutions. One is Manfred's: shooting objects that are very flat. The second is Rudi's: focus stacking.

I have no idea how one adjusts focus finely enough with your scope to be able to stack. That's one of the questions on my list for the experts who are going to introduce me to this next month. However, they work in a university lab with high-end equipment, so I don't know whether what they show me will be possible with your scope.

Very very carefully. Probably not. But i did buy it as a teaching tool and it does that admirably.

[Manfred M]

Based on the image in #8, I'd say +1 to what Dan say in #14.

You either need to stick with relatively flat subjects or figure out how to focus stack as the quality issues you are seeing in the images are very much related to the shallow DoF at the magnification level you are working at. I seem to remember sandwiching samples between two glass slides when I played with photo-microscopy. That maintained flatness, but one had to be careful of other issues that could occur; anything from damaging the sample to getting interference patterns in the image.