Correct Allignment of a Series 4 Stand

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
Message
Author
Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Correct Allignment of a Series 4 Stand

#1 Post by Timemaster1212 » Sat Aug 01, 2020 4:58 am

Alright folks, I apologize for the noobish questions, however I am quite stuck in a very quickly sinking boat. As i continue to experiment with my microscope to get better images, something seems very off with my phase. So, i went back to square one: Kholer Illumination. While the simple explanation is what i appear to be doing right, it is when i dig deeper into the actual physical properties of kholer that i realize I am missing some important steps. So, my question(s) is, on the series 4, adjusting of the lamp filament seems impossible. However, 2 screws exist for this very reason. Next, is the field diaphragm centering screws, located on the base. Is this how i center the field diaphragm when i look through my eye pieces? I believe these are my two big hurdles with the basics of my stand.

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Correct Allignment of a Series 4 Stand

#2 Post by BramHuntingNematodes » Sat Aug 01, 2020 5:47 am

Hmm the filament should be fixed in relationship to the collector lens well first off yeah use the two screws around the field Iris so that the circle of light is centered in your fov then how about you try focusing on your filament to see if it needs adjusting. For phase not working right dollars to donuts it's going to be your condenser but not a bad idea starting with the fundamentals
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#3 Post by Timemaster1212 » Sat Aug 01, 2020 6:05 am

Image
20x phase
If it helps this is the closest i can get to a test plate image haha. To me it seems very uneven and just off, if that makes any sense. However, everything was perfectly aligned, condenser speaking.

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Correct Allignment of a Series 4 Stand

#4 Post by BramHuntingNematodes » Sat Aug 01, 2020 12:13 pm

You got a phase telescope?
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#5 Post by Timemaster1212 » Sat Aug 01, 2020 6:03 pm

I do not, i have a built in Bertrand lens in my trinocular head that i use

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Correct Allignment of a Series 4 Stand

#6 Post by BramHuntingNematodes » Sat Aug 01, 2020 9:52 pm

well make with it man! What's it look like through there?
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

hans
Posts: 986
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Correct Allignment of a Series 4 Stand

#7 Post by hans » Sat Aug 01, 2020 10:14 pm

Timemaster1212 wrote:
Sat Aug 01, 2020 4:58 am
...on the series 4, adjusting of the lamp filament seems impossible. However, 2 screws exist for this very reason.
What exactly do you mean by this? That the screws exist and appear to function mechanically, but you don't see the effect you are expecting optically?

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#8 Post by Timemaster1212 » Sun Aug 02, 2020 5:51 am

LampCent.JPG
LampCent.JPG (34.31 KiB) Viewed 9433 times
As you can see, the lamp centering screws exist in the base. However the collecting lens directly in front of the bulb is frosted, making it (from what i read) impossible to center the filament.

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Correct Allignment of a Series 4 Stand

#9 Post by BramHuntingNematodes » Sun Aug 02, 2020 2:04 pm

I don't think an uncentered lamp in this case would cause severe performance problems particularly with a diffuser which will smooth over the image of the filament. Maybe in some very odd cases? In any case, if you can see light coming out if the light well you are almost all the way there. Certainly we wouldn't expect the dark brown images you got captured here. I'm still wondering about that condenser...
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

User avatar
75RR
Posts: 8207
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Correct Allignment of a Series 4 Stand

#10 Post by 75RR » Sun Aug 02, 2020 2:32 pm

Timemaster1212 wrote:
Sun Aug 02, 2020 5:51 am
LampCent.JPG
As you can see, the lamp centering screws exist in the base. However the collecting lens directly in front of the bulb is frosted, making it (from what i read) impossible to center the filament.
I don't think you have Köhler illumination, as you are unable to see and focus the filament. What you have is Critical illumination which should work perfectly well for you.

You should however be able to center the bulb roughly at the very least.


As to general setup - your condenser should ideally be just a millimeter or two below the slide when setup correctly if using medium to high objectives.
Timemaster1212 wrote:
Sat Aug 01, 2020 6:03 pm
I do not, i have a built in Bertrand lens in my trinocular head that i use
Can you post a photo of the centered phase ring and annulus?
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Correct Allignment of a Series 4 Stand

#11 Post by apochronaut » Sun Aug 02, 2020 4:22 pm

Actually, if you can focus the filament in the image plane , THAT is critical illumination but the series 4 doesn't rely on being able to see or not see the filament in order to align the illuminator. That microscope is easy to adjust to a Koehler condition and it gives excellent phase, when that is accomplished and the annuli and diaphragms are centered.

I think you must have received your microscope in a sorry state of alignment, so you need to follow a protocol, in order to get it aligned.

Follow this sequence. Forget ahout the phase ring alignment until the very end, when all of the preliminary alignment has been done.

If you have the correct bulb in the socket ; a GE 1493, it has a quite prefocused very forward filament which will be very close to being centered. The small filament centering screws are only needed for very fine trimming of the bulb. However, any small lack of alignment that exists , is irrelevant to your phase set up at this point.
Adjusting the illuminator and adjusting the phase alignment need to be kept as separate functions , although they affect each other. You start with adjusting the phase condenser basic alignment first , then trim the adjustment of the illuminator , then refine the phase condenser again, then finally align the annuli.
1) Turn the illuminator on to about 1/2 brightness
2) Turn the condenser to the O position.
3) Put the 10X objective over a subject on a slide.
4) Focus the 10X objective on the subject.
5) Close the field diaphragm
6) Adjust the condenser, either up or down until the diaphragm leaves are at best focus. With each subsequent objective they will get blurrier but that is normal.
7) Open the field diaphram about 1/2 way .
It is now time to adjust the illuminator.
8) With the field diaphragm in view, adjust the lamp until you get the brightest field .
9) With the mirror adjusting knobs, move the field diaphragm image towards the center of the field. If the field gets dimmer, adjust the lamp again for the brightest field.
10) Open the field diaphragm and close the condenser diaphragm. By opening and closing the the two, you should be able to get a determination of whether the two are concentric. Adjust the two with their respective centering screws until they are.
11) Center the field diaphragm circle dead center with the condenser alignment screws this time. The condenser diaphragm at this point will move with the field diaphragm because they are parcentered.
12) Adjust the lamp again in order to achieve the brightest field. The illumination should be quite uniform but with the 10X objective, there will be a slight browning around the periphery of the field.

It is now time to adjust your annuli. You can now adjust your illumination intensity to suit.
13) Move the condenser to the A position. Make sure both the subject is focused , the field diaphragm is focused and centered. Make sure the condenser diaphragm is wide open.
14) Engage the bertrand lens and focus it. Adjust your annulus concentric with the annular diaphragm ring.
15) Disengage the bertrand lens
16) Repeat steps 14 and 15 with each successive objective

You should get very precise phase, with well defined subject and detail borders with very limited halo and very little ca across about 50% of the center of the field and a slight increase toward the periphery.

You now have the two iris diaphragms aligned but it is still somewhat possible that the filament is not dead center. You only know that if a very slight hotspot exists right in the center of the field in B F. When it is still a bit off center after all the adjustment is done, you need to move the filament towards the field diaphragm center by adjusting the mirror. Visually, this looks like you are moving the diaphragm towards the filament. This will put the field diaphragm/ condenser iris parcentering out, so that will have to be fine tuned again, following the procedures above but the filament location, unless it is really off mainly affects peak overall intensity.
Last edited by apochronaut on Sun Aug 02, 2020 6:20 pm, edited 1 time in total.

hans
Posts: 986
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Correct Allignment of a Series 4 Stand

#12 Post by hans » Sun Aug 02, 2020 5:02 pm

Timemaster1212 wrote:
Sun Aug 02, 2020 5:51 am
As you can see, the lamp centering screws exist in the base. However the collecting lens directly in front of the bulb is frosted, making it (from what i read) impossible to center the filament.
Ah, yeah, the Reichert 410 also has a frosted collector lens which has confused me a bit. On the 410 there are no adjustment screws, I guess not necessary because it is using a much smaller halogen bulb where the location of the filament is more repeatable from one bulb to the next? I have still been messing around with alignment in the process of trying out LEDs, though, and even with the filament not sharply defined I can still center the diffuse blob in roughly the same way, with the goal of having symmetric falloff of intensity in all directions in the objective rear focal plane. One thing I have noticed: since the field of view of the blob that used to be the filament increases with increasing N.A. (and the apparent magnification in the objective rear focal plane decreases with increasing N.A.) the effect of centering may be more obvious with higher N.A. objectives.
75RR wrote:
Sun Aug 02, 2020 2:32 pm
I don't think you have Köhler illumination, as you are unable to see and focus the filament. What you have is Critical illumination which should work perfectly well for you.
It seems like the main practical issue in this context is what effect centering the bulb has. As long as the bulb is in a conjugate of the objective rear focal plane, as in Köhler, then that is where the effect of bulb centering shows up, even if the system not considered Köhler due to the presence of the diffusing element? This could be contrasted with critical illumination, where the effect of centering the bulb would show up mainly in the specimen plane, right?

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Correct Allignment of a Series 4 Stand

#13 Post by apochronaut » Sun Aug 02, 2020 6:40 pm

hans wrote:
Sun Aug 02, 2020 5:02 pm
Timemaster1212 wrote:
Sun Aug 02, 2020 5:51 am
As you can see, the lamp centering screws exist in the base. However the collecting lens directly in front of the bulb is frosted, making it (from what i read) impossible to center the filament.
Ah, yeah, the Reichert 410 also has a frosted collector lens which has confused me a bit. On the 410 there are no adjustment screws, I guess not necessary because it is using a much smaller halogen bulb where the location of the filament is more repeatable from one bulb to the next? I have still been messing around with alignment in the process of trying out LEDs, though, and even with the filament not sharply defined I can still center the diffuse blob in roughly the same way, with the goal of having symmetric falloff of intensity in all directions in the objective rear focal plane. One thing I have noticed: since the field of view of the blob that used to be the filament increases with increasing N.A. (and the apparent magnification in the objective rear focal plane decreases with increasing N.A.) the effect of centering may be more obvious with higher N.A. objectives.
75RR wrote:
Sun Aug 02, 2020 2:32 pm
I don't think you have Köhler illumination, as you are unable to see and focus the filament. What you have is Critical illumination which should work perfectly well for you.
It seems like the main practical issue in this context is what effect centering the bulb has. As long as the bulb is in a conjugate of the objective rear focal plane, as in Köhler, then that is where the effect of bulb centering shows up, even if the system not considered Köhler due to the presence of the diffusing element? This could be contrasted with critical illumination, where the effect of centering the bulb would show up mainly in the specimen plane, right?
If he has the correct bulb, the filament is actually quite small, about the same size as a 24 watt halogen, maybe smaller. It is also quite precisely placed in the bulb envelope. What little adjustment is available is entirely lateral and helps to mostly even out the field in BF but also results in maximizing the intensity of the system, since it is not the brightest. It's 18 watts coming from the back of the microscope. It is perfectly adequate for BF but with oil immersion phase every lumen counts, especially with Dark H.
Adjustment of the bulb is irrelevant to Koehler , since the filament is in a fixed position longitudinally and the combination of it's prefocus outside of the conjugate plane plus the diffuser lens means that it provides a good to excellent illumination source with the correct condenser, which I believe Adnan has. It is of course best if propperly centered but the quality of the phase is excellent nonetheless. I've even obtained very good phase with a 13 watt car signal bulb, which had a filament that wandered all over the place.

User avatar
75RR
Posts: 8207
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Correct Allignment of a Series 4 Stand

#14 Post by 75RR » Sun Aug 02, 2020 7:32 pm

hans wrote:
Sun Aug 02, 2020 5:02 pm
It seems like the main practical issue in this context is what effect centering the bulb has. As long as the bulb is in a conjugate of the objective rear focal plane, as in Köhler, then that is where the effect of bulb centering shows up, even if the system not considered Köhler due to the presence of the diffusing element? This could be contrasted with critical illumination, where the effect of centering the bulb would show up mainly in the specimen plane, right?
I was under the impression that there were two types of illumination. Köhler and failing that, Critical.

Reading through Frithjof A. S. Sterrenburg's Microscopy Primer http://www.microscopy-uk.org.uk/index.h ... /intro.htm to refresh my memory it appears that they are three.

Critical illumination which has a collector lens focused at infinity (it requires a condenser corrected for infinity)

Köhler illumination which has a collector lens focused on the condenser iris diaphragm i.e. front focal plane (it requires a condenser corrected for a short distance, usually around 35cm)

and a third which according to Sterrenburg is equivalent to a desk lamp :)
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

hans
Posts: 986
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Correct Allignment of a Series 4 Stand

#15 Post by hans » Sun Aug 02, 2020 8:39 pm

75RR wrote:
Sun Aug 02, 2020 7:32 pm
I was under the impression that there were two types of illumination. Köhler and failing that, Critical...
I don't really have a clear understanding of how people are typically defining Köhler. I guess I was just suggesting that, in a narrow context, maybe it is sufficient and preferrable to refer directly to the specific characteristic that is relevant (in this case, which type of conjugate plane the illumination source is located in) and avoid the broader question of what sets of characteristics should be used to define Köhler vs. critical vs. whatever else.

hans
Posts: 986
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Correct Allignment of a Series 4 Stand

#16 Post by hans » Sun Aug 02, 2020 8:59 pm

apochronaut wrote:
Sun Aug 02, 2020 6:40 pm
If he has the correct bulb, the filament is actually quite small, about the same size as a 24 watt halogen, maybe smaller. It is also quite precisely placed in the bulb envelope.
Interesting, I was assuming otherwise due the the much larger bulb, but I guess maybe if it is glass/tungsten that it necessary for thermal reasons vs. quartz/tungsten/halogen where the bulb has to get hot enough for the halogen thing to work?
apochronaut wrote:
Sun Aug 02, 2020 6:40 pm
Adjustment of the bulb is irrelevant to Koehler , since the filament is in a fixed position longitudinally and the combination of it's prefocus outside of the conjugate plane plus the diffuser lens means that it provides a good to excellent illumination source with the correct condenser, which I believe Adnan has. It is of course best if propperly centered but the quality of the phase is excellent nonetheless. I've even obtained very good phase with a 13 watt car signal bulb, which had a filament that wandered all over the place.
Yeah, this is what I have observed with the stock illumination in the 410, you would have to misalign the bulb more than is possible with normal manufacturing tolerances and assembly slop to get any really obvious effect optically. But since bulb position is still much closer to being conjugate to the back focal plane than to the specimen plane, what I see when trying to position LEDs is an obvious off-center blob in the phase telescope and a much more uniform dimming effect in the normal field of view.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Correct Allignment of a Series 4 Stand

#17 Post by apochronaut » Sun Aug 02, 2020 10:42 pm

hans wrote:
Sun Aug 02, 2020 8:39 pm
75RR wrote:
Sun Aug 02, 2020 7:32 pm
I was under the impression that there were two types of illumination. Köhler and failing that, Critical...
I don't really have a clear understanding of how people are typically defining Köhler. I guess I was just suggesting that, in a narrow context, maybe it is sufficient and preferrable to refer directly to the specific characteristic that is relevant (in this case, which type of conjugate plane the illumination source is located in) and avoid the broader question of what sets of characteristics should be used to define Köhler vs. critical vs. whatever else.
It would seem that there are a sufficient number of people that regard Koehler illumination as a theoretical concept that exists in books and that there are physical examples manufactured that adhere to that concept.
However, there are numerous examples of illumination systems that achieve equivalent results to a well designed Koehler system and do not conform to the classic Koehler design. In some cases, they are very distant.

One should not forget the reason that Koehler illumination exists. It is entirely based on the invention of the coiled filament, which turns out to be structurally , a bad source of light for a microscope. Ribbon filaments are good sources but in the economy of filament bulbs , the coiled filament became King and a practical modification was found to render the cheap but poor light source, adequate. It stuck for about 100 years.

The idea that there are only three types of illumination for microscopes is based on there being established names and a specific plane of focus for 2 of them and all else being regarded as unnamed or unfocused and therefore being tossed into a pile.

There are various optical designs that include diffusers, additional lenses and aux. condensers that are not Koehler in principal but get a result that is consistent with Koehler theory and recently, there is the possibility of an led design achieving critical illumination results with simple ingredients.

The microscope that is the topic of this thread I would call a modified Koehler type, having an easily adjusted filament bulb that can achieve an even , bright illumination field in the conjugate planes required for phase microscopy.

User avatar
75RR
Posts: 8207
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Correct Allignment of a Series 4 Stand

#18 Post by 75RR » Mon Aug 03, 2020 5:07 am

apochronaut wrote:
Sun Aug 02, 2020 10:42 pm
The microscope that is the topic of this thread I would call a modified Koehler type, having an easily adjusted filament bulb that can achieve an even , bright illumination field in the conjugate planes required for phase microscopy.

Image

Given that the only adjustment possible in that illumination system is centering the bulb (see reference sheet image),

and that there is no mention of a focusing lens let alone where it might be focused if there were one,

calling this Köhler is more than a stretch, it is wishful thinking.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#19 Post by Timemaster1212 » Mon Aug 03, 2020 6:06 am

Wow, thank you everyone for the wealth of information, work caught me up today so sorry for the lack of communication.
75RR wrote:
Mon Aug 03, 2020 5:07 am
apochronaut wrote:
Sun Aug 02, 2020 10:42 pm
The microscope that is the topic of this thread I would call a modified Koehler type, having an easily adjusted filament bulb that can achieve an even , bright illumination field in the conjugate planes required for phase microscopy.

Image

Given that the only adjustment possible in that illumination system is centering the bulb (see reference sheet image),

and that there is no mention of a focusing lens let alone where it might be focused if there were one,

calling this Köhler is more than a stretch, it is wishful thinking.
After looking into information on Kholer, that is what i assumed how the illumination system works. It seems to work well, however it was uneven for man y of my images.

Apo, thank you especially for the setup information with my stand, something i will experiment with tomorrow (or maybe later today haha). With the built in ertrand lens, is focusing required? I can see (very poorly i may add, but i can see well enough) to center what i believe is properly. I will see what happens tomorrow. Also, all this talk about bulb filament and such made me think, is the original system worth trying to stress to perfect?

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Correct Allignment of a Series 4 Stand

#20 Post by apochronaut » Mon Aug 03, 2020 2:04 pm

The original bulb works fine or at least the one that works fine, works fine. There is a bit of conflicting information out there regarding the correct bulb. Neeley's site says GE 88 and says the catalogue recommends it. That is a 13 watt bulb . Very uneven filament. Similar to a car signal bulb. I have tried one, and it works o.k. but the image quality is stressed with oil immersion. The GE 1493 is an 18 watt bulb . It is a scientific bulb with a very precisely placed filament if properly made. There are many cheap knockoffs of that bulb and some have a standard C 6 convex coil filament , where the correct filament type is an FF , which is a coiled, coil and is only about 3mm linear. It has a compact, almost pinpoint radiance, rather than the broader spreading luminance that a convex wire filament gives. Since a small bright filament is being diffused to fill the field at the field diaphragm, in addition to the convex wire filament(s) providing a weaker luminance, some of the light probably falls outside of the perimeter of the field diaphragm unable to be captured by the condenser. The bulb needs no longitudinal focus. It is designed to provide the quality of illumination required for high quality phase microscopy . The filament is perfectly defocused at the field diaphragm. The objective is focused on the subject, the field diaphragm is adjusted to be in focus at the image plane and the annular diaphragm and phase plates are therefore in conjugate focus. The only illumination adjustment required is a small amount of centering.

You may have mis-interpreted my reference to focusing the bertrand lens. I was not suggesting focusing the microscope; that would put everything off. The Bertrand lens has a push pull focusing ring which allows you to more accurately define the annular borders, for more precise centering.

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Correct Allignment of a Series 4 Stand

#21 Post by BramHuntingNematodes » Mon Aug 03, 2020 2:42 pm

Image

I think of it as this although a lot of the emphasis is on the part B and below. If one reads the whole article it's pretty clear that it is a very practical treatment of a particular setup with some interesting improvisations from our eponymous and perhaps impecunious microscopist Kohler.

You could probably strip this down further and say you have a Kohler setup with just two irises (or holes punched in cardboard as Kohler had) and a collector lens. Apo says you could even do away with the field iris leaving the Kohler setup to just a collector lens and condenser iris. Does seem like a lot of hoopla over just that!
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Correct Allignment of a Series 4 Stand

#22 Post by apochronaut » Mon Aug 03, 2020 3:18 pm

I said that the field iris is used as a location to focus on , a convenient tool with which to focus the conjugate planes. You could just as easily use the point of a pin. The field diaphragm itself ls not intrinsic to Koehler illumination. It participates in the process of longitudinal and axial alignment but a type of illumination consistent with the principal of Koehler illumination can exist with no field diaphragm.
In BF the only negative effect of not having a field diaphragm would be the inability to adjust contrast . Koehler is a technique to defocus an inadequate light source into a uniform blur. Contrast is affected by that technique but it is not the objective of it.
In phase contrast, which is kind of the focus if this thread, the field diaphragm is completely irrelevant. The location of the field diaphragm as an alignment feature , something to focus on is relevant but once the alignment has been performed, you could remove the field diaphragm altogether and still achieve perfect results. In other words the diaphragm can and preferably is wide open all the time, as is the condenser iris. The contrast, and increased resolution inherent to phase are provided by the illumination beam focal point, or defocal point, and the location of the annular diaphragm, the condenser rear and front focus and corrections, the objective focus and the location of the phase plate. The phase plate by the way, need not be at the back focal plane.

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Correct Allignment of a Series 4 Stand

#23 Post by BramHuntingNematodes » Mon Aug 03, 2020 3:38 pm

Right right, all that stuff. In any case, I can't think that the filament position is what's going to solve this problem, particularly looking at some earlier shots Timemaster posted from brightfield(?). Why do they all look so very dark and grainy? Looks like they have a good camera, so that's not it. Timemaster would you say these photos look about like it does through the eyepiece? You want to open up your condenser diaphragm a little maybe? I have one AO phase contrast lens (finite tube length though) and although its front lens is cracked and I don't have an exactly matching annulus and it is still pretty darn good. I think maybe something more elemental is going wrong. Like, is light coming out of the well? If you put a piece of paper over it, does the light shining through make a pretty circular shape? Is the condenser diaphragm all the way open?
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Correct Allignment of a Series 4 Stand

#24 Post by BramHuntingNematodes » Mon Aug 03, 2020 3:49 pm

Also, remind me, this is a different stand than the one with the busted out mirror on the bottom?
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#25 Post by Timemaster1212 » Mon Aug 03, 2020 5:56 pm

Yessir, this is indeed a different stand. I retired that one and have been using it for parts. And perhaps my bulb is the source of all of this, i do not believe it is the proper one. And apo, i still do not see how one could focus the Bertrand lens with it built into the head. Is it prefocused then? Or is some tinkering required to fix it haha.

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#26 Post by Timemaster1212 » Mon Aug 03, 2020 6:04 pm

Oh and i forgot to add, if brightfield, the images look better through the eyepieces than through the camera, something i am sorting out still. However phase is a different monster, it all looks very off through the eye pieces and through the camera.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Correct Allignment of a Series 4 Stand

#27 Post by apochronaut » Tue Aug 04, 2020 2:32 am

Timemaster1212 wrote:
Mon Aug 03, 2020 5:56 pm
Yessir, this is indeed a different stand. I retired that one and have been using it for parts. And perhaps my bulb is the source of all of this, i do not believe it is the proper one. And apo, i still do not see how one could focus the Bertrand lens with it built into the head. Is it prefocused then? Or is some tinkering required to fix it haha.
The knurled ring moves the lens up or down in order to accurately focus on the specific annulus combination. It is not fixed.

apochronaut
Posts: 6272
Joined: Fri May 15, 2015 12:15 am

Re: Correct Allignment of a Series 4 Stand

#28 Post by apochronaut » Tue Aug 04, 2020 2:52 am

Timemaster1212 wrote:
Mon Aug 03, 2020 6:04 pm
Oh and i forgot to add, if brightfield, the images look better through the eyepieces than through the camera, something i am sorting out still. However phase is a different monster, it all looks very off through the eye pieces and through the camera.
Not unusual. Camera adjustment tricks come with some experience and we get turned into believing that microscope images are just a stream of focus stacked stills. While most of those are worthy of being printed onto Chinese made vinyl shower curtains; I mean they are so cute, and they show the eyelashes and everything!.... , the experience and understanding of the natural world through the microscope is a whole other thing than focus stacked kitsch. Refine your photos as much as you can but learn from the 99% of the time yodu are at the eyepieces, rather than the 1% of the time you are twiddling the dials, maybe imagining the sputum sample you just photoed might make it to a commercial wallpaper printer.
Photos are always behind the times.

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#29 Post by Timemaster1212 » Tue Aug 04, 2020 7:08 am

Alright! Progress (i think) made!

Same 20x magnification, no editing, just straight from the camera.
Image

Now the light path is dirty and the focus is not the best, however as a preliminary test of the new adjustments i think it looks much better.

Timemaster1212
Posts: 127
Joined: Sun Dec 03, 2017 12:21 am

Re: Correct Allignment of a Series 4 Stand

#30 Post by Timemaster1212 » Tue Aug 04, 2020 7:19 am

Alright when i put my glasses on i realized how bad it really was haha, this should be a better after redoing the test.
Image

Post Reply