Microscope Objective Clarification

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Deanimator
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Microscope Objective Clarification

Post by Deanimator »

I'm getting ready to pull the trigger on a basic microscope objective rig, and have a simple question:

In the photo below, what is the piece between the RMS to M42 adapter and the tube lens? What is it called and how does it attach to the tube lens?

Image

Ichthyophthirius
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Post by Ichthyophthirius »

Hi,

Do you mean this? http://www.photozone.de/images/8Reviews ... 6/lens.jpg

In this zoom objective, the front simply extends a lot. Other zooms may extend less.

Regards, Ichty

Pau
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Post by Pau »

what is the piece between the RMS to M42 adapter and the tube lens?
It isn't RMS, CFI objectives have M25X0.75 thread. The other ring is to go from M42 to the filter thread. You can also find direct adapters from the objective thread to the filter thread.
In this zoom objective, the front simply extends a lot. Other zooms may extend a lot less or have internal zoom
Yes, but because Rik uses an horizontal setup and focusing is not been done with the zoom lens this is not likely an issue. I use a 70-200 f4 L IS with internal focus and zoom and it's much nicer although I'm not sure if it provides much advantage as tube lens aside being much more solid and useful for a vertical setup at different magnifications.
Pau

rjlittlefield
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Post by rjlittlefield »

In the picture, nothing is M42. The adapter is a single piece, 25mm to fit the objective and 52mm to fit the filter thread of the lens. See https://www.ebay.com/itm/Nikon-CFI-M25- ... 2570669850 , or search ebay for m25 m52 adapter .

Sometimes I do use that zoom in vertical configuration. The problem then is that lens focus wants to shift away from infinity. But that's easily solved with a piece of blue painters tape wrapped around the lens rings to keep them from turning.

--Rik

Deanimator
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Post by Deanimator »

Ichthyophthirius wrote:Hi,

Do you mean this? http://www.photozone.de/images/8Reviews ... 6/lens.jpg

In this zoom objective, the front simply extends a lot. Other zooms may extend less.

Regards, Ichty
Ok, that makes more sense.

Unlike the finite objective picture in the FAQ, the infinite pictures lack the detail.

At least initially, I'll be using my ProMaster 70-300mm zoom as the tube lens.

Thanks.

Deanimator
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Post by Deanimator »

Pau wrote:It isn't RMS, CFI objectives have M25X0.75 thread. The other ring is to go from M42 to the filter thread. You can also find direct adapters from the objective thread to the filter thread.
I was going to cite a particular objective but on reflection, I ought instead to take a step back and solicit suggestions for an economical infinity objective based rig capable of modest magnifications.

My current equipment:
  1. Canon T4i
  2. ProMaster 70-300mm zoom (for a tube lens)
  3. Wemacro
  4. for illumination a choice of:
    • 2 300w CFLs
    • 2 Jansjo LED lamps
    • 3 manual flashes with wireless triggers

This is purely for personal entertainment. It's never going to be used for a commercial or institutional purpose.

Given my level of experience (or lack thereof) in using microscope objectives, I'm probably better off buying a new in the box entry level objective, rather than trying to get a bargain on a better quality used item (Nikon, etc.).

Since I already have everything besides the directly objective related items, using something like an Amscope objective, I think that I would come in well under $200.

I'm looking to have everything put together by Christmas.

I need to know:
  1. what infinity objective (4-10x) to buy.
  2. what accessories to buy.
  3. recommended source(s)
Now that I have my Wemacro and am comfortable using it, I am ready to move forward.

Thanks.

rjlittlefield
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Post by rjlittlefield »

Deanimator wrote:Unlike the finite objective picture in the FAQ, the infinite pictures lack the detail.
True at the time you read it. I just now edited the FAQ to fix that oversight.

--Rik

Deanimator
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Post by Deanimator »

rjlittlefield wrote:
Deanimator wrote:Unlike the finite objective picture in the FAQ, the infinite pictures lack the detail.
True at the time you read it. I just now edited the FAQ to fix that oversight.

--Rik
Thanks.

That was quick work! :D

mawyatt
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Post by mawyatt »

Deanimator wrote:
rjlittlefield wrote:
Deanimator wrote:Unlike the finite objective picture in the FAQ, the infinite pictures lack the detail.
True at the time you read it. I just now edited the FAQ to fix that oversight.

--Rik
Thanks.

That was quick work! :D
These images were taken with Wemacro 4X inf NA 0.1 Don't know if this is same lens as the AmScope though, as I haven't tested the AmScope equivalent.

http://www.wemacro.com/?product=4x-infi ... ctive-lens

https://www.photomacrography.net/forum/ ... hp?t=35798

https://1.img-dpreview.com/files/p/E~fo ... 50eaa3d598

https://4.img-dpreview.com/files/p/E~fo ... 1c589028fa

AmScope has a good 4X (160mm extension) lens that I have tested.
https://www.closeuphotography.com/generic-objectives

Lots of these cheap lens look alike and may even have the same outer casing, but may have different glass inside!! Make sure you get the correct lens, otherwise you are likely to be disappointed.

Mike

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Post by Deanimator »

mawyatt wrote:
Deanimator wrote:
rjlittlefield wrote:
Deanimator wrote:Unlike the finite objective picture in the FAQ, the infinite pictures lack the detail.
True at the time you read it. I just now edited the FAQ to fix that oversight.

--Rik
Thanks.

That was quick work! :D
These images were taken with Wemacro 4X inf NA 0.1 Don't know if this is same lens as the AmScope though, as I haven't tested the AmScope equivalent.

http://www.wemacro.com/?product=4x-infi ... ctive-lens

https://www.photomacrography.net/forum/ ... hp?t=35798

https://1.img-dpreview.com/files/p/E~fo ... 50eaa3d598

https://4.img-dpreview.com/files/p/E~fo ... 1c589028fa

AmScope has a good 4X (160mm extension) lens that I have tested.
https://www.closeuphotography.com/generic-objectives

Lots of these cheap lens look alike and may even have the same outer casing, but may have different glass inside!! Make sure you get the correct lens, otherwise you are likely to be disappointed.

Mike
That's very useful information. Thanks.

I previously read that article on the 4x Amscope and was impressed. Would you recommend that one instead of an infinite objective?

mawyatt
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Post by mawyatt »

Deanimator wrote:
mawyatt wrote:
Deanimator wrote:
rjlittlefield wrote:
Deanimator wrote:Unlike the finite objective picture in the FAQ, the infinite pictures lack the detail.
True at the time you read it. I just now edited the FAQ to fix that oversight.

--Rik
Thanks.

That was quick work! :D
These images were taken with Wemacro 4X inf NA 0.1 Don't know if this is same lens as the AmScope though, as I haven't tested the AmScope equivalent.

http://www.wemacro.com/?product=4x-infi ... ctive-lens

https://www.photomacrography.net/forum/ ... hp?t=35798

https://1.img-dpreview.com/files/p/E~fo ... 50eaa3d598

https://4.img-dpreview.com/files/p/E~fo ... 1c589028fa

AmScope has a good 4X (160mm extension) lens that I have tested.
https://www.closeuphotography.com/generic-objectives

Lots of these cheap lens look alike and may even have the same outer casing, but may have different glass inside!! Make sure you get the correct lens, otherwise you are likely to be disappointed.

Mike
That's very useful information. Thanks.

I previously read that article on the 4x Amscope and was impressed. Would you recommend that one instead of an infinite objective?
They both are quite good, not Mitutoyo level, but considering the cost a great value IMO. The WeMacro 4X Inf. requires a tube lens, for these images I used a old Nikon 200mm F4 "Q" that I got for ~$20 shipping included. It had stuck aperture blades which I fixed with Richard Haw's site help. Canon may have an old film 200mm F4 lens that would work well too, but I only use Nikon so can't say for sure.

The 4X AmScope that Robert discovered just requires a 160mm extension, which you make out of cheap eBay extension tubes, or better yet a bellows. If you get the extension tubes be sure to flock the heck out of them as they reflect everything even though they appear to be black!! Don't forget the lens adapter too!! Get Protostar or Beetle Black for flocking material.

I've found these work well for extension tubes with my Nikons. You'll need the Canon equivalent. Get extras because some of the sections may not fit very good, I got 4 sets. You'll need a Canon mount to whatever your objective adapter thread size is to mount to the front of the extension tubes. These tubes are nice and wide and allow plenty of room for flocking.
https://www.ebay.com/itm/Macro-Lens-Ext ... 2749.l2649

So either way you can get within your $200 budget. If you pay close attention and find a good deal on an old Canon 200mm F4, you might be able to get both setups. If you do, then run a test and let us know what you find.

BTW you might find your intended tube lens will vignette heavily at 200mm since it's a zoom to 300mm, so not fully extended at 200mm.

Good luck,

Best,

Mike

ChrisR
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Post by ChrisR »

Your zoom will be far from ideal, probably only working without vignetting at the 300mm end.

Don't forget the Raynoxes work well as tube lenses (125mm and 208mm) as does the Sigma 52mm diameter close-up diopter. (200mm).
Chris R

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Post by rjlittlefield »

"Raynox DCR-150 tube assembly with flocking" is discussed at http://www.photomacrography.net/forum/v ... hp?t=35350 .

--Rik

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Post by Deanimator »

I'm still doing my research, but right now I'm leaning toward the $17 Amscope finite objective and supporting equipment. This is based on a combination of expense and simplicity of configuration. Given the low expense from not having to purchase some kind of tube lens, I may pick up both a couple of sets of M42 extension tubes and a bellows.

My only issue (regardless of approach) is the inability to purchase everything from one domestic source. I prefer to buy everything from Amazon Prime, but that's just not going to be possible in this case.

I have a question regarding the Amscope products(s):

I can get the objective from Amazon, however I also saw this kit:

https://www.amazon.com/AmScope-4X-100X- ... S5CBGCZZKE

It appears to include the 4x finite plus three others. Does this seem like something worth getting instead of the 4x alone?

I've got to get moving, since I need to buy my mother a George Foreman grill to replace the one she blew up (along with her kitchen) in a gas explosion. I'm trying to have everything show up here, her place, or at other destinations before Christmas. So, I'm going to order her Christmas present and the photogmicrography gear after I get off work tomorrow morning.

I have no doubt that I'm going to have a lot more questions shortly.

Thanks to everyone who helped along the way, either with suggestions or improving the already abundant documentation.

Pau
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Post by Pau »

Don't buy the 4 objectives set: they are inferior, see the difference with the Plan objective, and you only could profit for macro the 4X and 10X and both likely not very adequate for the task, they are entry level optics to work in cheap school grade microscopes
Pau

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