MicrobeHunter.com Microscopy Forum

So I'm narrowing down to the scope I want to buy, I want to view living cells and found out I need a phase contrast scope and I'm not buying anything used. This is what I found, from what I read it seems to do everything I need, I also don't have to use stains to view the living cells.

http://www.microscopenet.com/omax-40x20 ... 11017.html

What are your thoughts?

Hi,

Honestly, in my opinion, I think this setup would be all you would ever need... I am sure you will get other opinions that you could do better.. To me, I have kept an eye on Ebay for these elusive "Big Four" stands that rarely appear.. After you purchase one, there seems to be the endless search for the things that are missing from it.. If I was spending that much money I would do it.. Just MHO...

BillT

Looks good to me as well. Only thing I can add is the 20X eyepieces are useless and only provide "empty" magnification.

thanks guys, now with this microscope can I view normal non-living cells just as well as living cells? i'm new to this so i don't want to assume anything.

Now that I've had both AmScopes for several months now, I found
having purchased the 16X eye pieces a good investment for the money.
I use them as much of the time as the 10X. Not sure if OMAX sells
15X or 16X and not expensive for future purchase.



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1st AmScope M200B-MS Converted to LED
Camera OMAX A3550U 5mp
2nd AmScope T340B-DK-LED

The extra oculars at various magnifications can be had relatively cheap on Ebay... I am sure the Omax has a standard 23mm opening.. I know there are some special eyepieces out there, but by far the most common are 23 and 30mm sizes.. the 30mm is used mainly on stereoscopes..

BillT

thanks guys, now with this microscope can I view normal non-living cells just as well as living cells? i'm new to this so i don't want to assume anything.

Yes. As a matter of fact, living cells are easier to observe with this one, as it has phase contrast. Living cells (especially bacteria) are transparent and therefore can be more easily seen in phase contrast. Bacteria, however, are not very interesting anyway. You can also remove the phase contrast condenser and use the phase contrast objectives as normal brightfield objectives. So you have the options. On the other hand, there are also plenty of living cells in water that you can see without staining and without phase contrast, so it is not necessary. But I do admit, that phase contrast is indeed nice to have as it produces more impressive images with many specimens.

Oliver.

I found having purchased the 16X eye pieces a good investment for the money.

I also purchased a pair of 16X eyepieces. I use them occasionally before I decide if I want to switch to the 60X or oil the 100X obj. but for the price they are a good investment.

Starguy75, go for it and after you get it let us know how you are doing and share some images.

Don't expect perfect views "Out of the box". Takes practice and trial and error but that is part of the fun of this hobby.

JimT

I have a very similar OMAX microscope for the some time. Some thoughts:

1. This 14MP USB3 ToupCam camera costs a lot compared to the microscope itself. This thing is very convenient, but I and other people had serious issues with image quality - for example, very uneven background color in brightfield. Think about if you really need this, or maybe a cheaper camera model, or maybe no USB camera at all (I've ended up buying a micro four thirds mirrorless camera and don't use my USB camera anymore).
2. This microscope doesn't have a built-in field diaphragm. I think this is of extremely importance and you need to buy one. It's called "Microscope Kohler Illumination Attachment with Iris Field Diaphragm and Center Adjustment" on the page you linked.
3. The default eyepieces are not high eyepoint ones, not good if you wear prescription glasses.
4. You really should buy plan objectives if you want to do photos.
5. The 20x eyepieces are useless in my opinion.

Well, in my experience all of kit1980's points are accurate - except perhaps for the 1st, as I used a 2mp (USBII) Toupcam before I hooked-up a Canon DSLR to my 'scope and find the only really significant advantage to be the 18mp of the Canon inasmuch as it enables cropping without detail-loss.
The (properly configured) USBIII capability of the Toupcam will give a smooth live image at far higher resolution than my 2mp USBII version - should be as smooth as the DSLR when working properly - obviously your computer must have a USBIII port to take advantage of that capability. I'd double-check that the camera is USBIII as they really are very expensive and would represent a large part of that 'scope's value...

Kohler (i.e. with use of field-diaphragm - an iris directly over the light-source) in my experience makes a huge difference - greatly reduces glare I definitely find.

Definitely agree re the spectacle-eyepieces (marked with small spectacle symbol) - they allow a very comfortable position if you wear glasses - so much more relaxing to be able to 'stand-off' a few mm rather than press up against the eyepiece glass so much.

'Plan' objectives - again when I upgraded to plan objectives the flat field immediately proved to be very significant indeed - there really is a huge difference, especially as said with photography.

Also must agree with eyepieces above x10 - not much point IMHO.

Just my few observations.

I'll just say I agree with the comments about plan objectives - this makes a difference.

They camera thing is a tricky one. I use a canon 1200d DSLR with the adapter for Canon DSLR shown in the products on the page (with my own, different, chinese scope)
The canon 1200D was £230 (about $300) (Us -> EOS Rebel T5 ) is 18MP and is possibly better value for money than the toup cam.
But that is speculation on my part, as I haven't compared.

I personally found very little advantage in using high resolution DSLR vs lower resolution microscope cameras. Although I do use DSLR on my scopes, I do it mostly for the convenience and not having to recalculate magnification when full sensor camera is used with correct 35mm photo attachment.


Now, as far as observing living cells, whether it would be tissue culture or pond water, the best way of doing that is using inverted microscope, where the sample is positioned above the objectives. The advantages is that you can use optical quality reservoirs such as mini Petri dishes and tissue culture flasks, and with low magnification objective you can scan the field much more efficiently (your specimen will be much much larger).

I think Plan objectives are almost necessary for the lower powers but for 40X or above because the DOF is so narrow I don't think they you will need them.

Go for it. You can always add more capabilities as you gain experience.

JimT

I read the specs several times and could not tell if the phase condenser had the non-phase
position that allows the phase abjective to be a brightfield objective.
I have used 10x, 15X, and 20x on all 3 types of scopes, and I found the 10X and
15X to be very useful, the 20X was useless. I found the formulas that give maximum
useable magnification accurate for my amateur purposes.
It is amazing they would sell a phase scope without the Kohler hardware, I would
get it with the scope.
Do you have any specific cells you wish to see?
One last thing, I had no trouble seeing the difference between achromatic and plan-
achromatic objectives. But, hey, if you have a mess of cells fillng the view just crop
the perimeter.
Dale

Dale wrote:I read the specs several times and could not tell if the phase condenser had the non-phase
position that allows the phase abjective to be a brightfield objective...
Dale

You need to put your reading glasses on Dale.
Under the Features:
'Four phase contrast lenses and one bright field Abbe condenser on one disk, fast and easy to switch, no condenser change needed'

For those reading this from the U.S., bear in mind that the price is actually about $1100.00 U.S. It still seems like 1452.59 to Canadians, though.
Omax microscope kits seem to have a lot of not very important bells and whistles on the more expensive microscopes, rather than including what really counts. I'm on board with a 500.00 phase contrast Omax but at this price you would think that some sort of major improvement might be in order. The retailer seems to cloud the issue with 1/2 truths and a big list of tid bits that are not particularly valuable.
Here's what's wrong . 1) no plan optics. An off brand Asian scope should be plan at this price 2) a wimpy 18mm field of view. Should be at least 20mm 3) the 20X eyepieces are superficial pieces of junk and are a waste of money. They would only be usable with the 10X objective, otherwise empty magnification would result, so why pay for them? 4) only a 4 position nosepiece. Should be a 5 position at this price. 5) 3 watt led is wimpy. Should be at least 5watt 6) no kohler illumination mentioned. It seems to have only variable intensity which can be found on any 200.00 microscope. In fact the entire illumination system is about the same as a 200.00 microscope would carry. 7) The promotional literature is full of B.S. and obvious truths. Half of the listed features are just normal features most microscopes have. The fact that you can view live cells without staining is just nonsense. Any microscope can do that. Phase contrast does make that somewhat better but without kohler illumination the phase contrast on this microscope will likely be subpar, or no better than the phase contrast on a 500.00 scope, and the 100X, probably will be dimly illuminated to boot.
There is nothing on this microscope that justifies 1452.59 CDN. and the very idea that it has been discounted from it's regular price of $3,828.60 is just ludicrous.

Completely agree with Apochromat. This is a typical $200 chinese microscope with lots of marketing BS and some no-so-needed accessories. ....and there is no such thing as 2000x magnification in visible light transmitted microscopy. Maximum resolving magnification sits somewhere around 1300-1400x, and this IF you have top quality objectives and eyepieces as well as optimal Kohler illumination.

Charles wrote:

Dale wrote:I read the specs several times and could not tell if the phase condenser had the non-phase
position that allows the phase abjective to be a brightfield objective...
Dale

You need to put your reading glasses on Dale.
Under the Features:
'Four phase contrast lenses and one bright field Abbe condenser on one disk, fast and easy to switch, no condenser change needed'

Don't need no readin glasses, I have 30mm Nikon eyepieces glued to my eyelids!
I did read that feature, but did not interpret it to mean there was a position for brightfield. I would like to assume there
is, but I didn't feel right assuming. On the 'bright' side, I went back and reread that feature, then looked at a couple of
'brightfield' websites, finding one that was waaay over my head, giving me something to grind my brains on during the flight
to Hawaii. I intend to conquer this NA thing.
Dale

I agree one hundred percent with APO. I am not sure why a good "big 4" microscope is so elusive. I have bought and sold several over the last few months. As I have mentioned including Olympus BH-2's one with widefield head and eyepieces etc.

Sold an AO 120 with phase contrast for half the price of this scope as well as an AO10 with phase contrast for less than half. Picked up a Leitz with phase contrast and plan objectives for less than half .

Just saying...

Getting a good quality used unit from th Reputable manufacturer is pretty easy. Just keep it simple for the first unit. There is , for exampe a completely recondicioned Universal on eBay right now (with planapo 63 and planapo 100, no delamination) from 100% feedback microscope dealer for $900 shipped.