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MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8 Review RSS Feed

MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8

Reviews Views Date of last review
10 65,401 Thu January 26, 2023
Recommended By Average Price Average User Rating
90% of reviewers $116.67 8.13
MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8

MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8
MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8
MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8
MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8

These are Russian built "maksutov" mirror lenses, production started in the 1950's and continued until the end of the USSR. There are several different models. Online posts indicate the original MTO is an exacta mount, and a different, slimmer body, and was made by KMZ. Then subsequently there was a M39 screw thread mount lens with a 45.2mm registration distance (but infinity focus is normally achievable with just a simple 39-42mm adapter). This thread notes that actual t-mount ones were made for export in the late1960's. Otherwise the LZOS made 3M-5A is the soviet style "t-mount" - the mount will remove to leave a mounting like the internal collar of a standard t-mount. Other t-rings can then be fitted, though there is a mix 'n match process to find one that is the same size internally. Note that there is no M42 x 0.75 thread - don't try to unscrew the mount.

The 3M-5A was superceded by the 3M-5CA - a lighter design that dispensed with the hood and tripod mount collar (pic 4). That was finally superceded by a lighter more modern design with plastic parts - the ZM-5A.
Pics 1, 2 are of a 3M-5A; pic 3 of a classic MTO with the large mirror housing. Note the early MTO particularly can have problems mounting on dslr due to that large mirror housing/tripod mount ring coming up against the protruding prism housing on many cameras.
Much less common is a very similar MTO 550mm f8.5.
There is also a 3M-6A (=/similar to rubinar? ) 500mm f5.6.

Filter size: 77mm (MTO/3M-5A); 72mm - later designs.
Weight: MTO =1225g; 3M-5CA =620g;
SIze: MTO ~15.5cm;
Close focus: 4m;
Focus throw: ; focuses past infinity.
MTO/3M-5A: two lens collar mount points, one for portrait and one for landscape, each 1 x 1/4" 1 x 3/8".
Hood: built in retractable.
A full set is a cased lens with 4 filters, orange, green, UV and a NC type filter. review.

Review of 3M-5CA on mflenses.

Kepplers vault 61: mirror lenses. - Mike Eckeman. This blog page includes interesting scans from photography magazines of the time.

Good comparison with canon AF 300mm +tc - mk5 full frame
Mount Type: M42 Screwmount
Price History:

Add Review of MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-10 of 10

Registered: April, 2012
Posts: 925
Review Date: January 26, 2023 Recommended | Price: $200.00 | Rating: 8 

Pros: Good sharpness
Cons: Focusing stiff
Sharpness: 8    Aberrations: 8    Bokeh: 5    Handling: 6    Value: 10    Camera Used: K3   

I bought this lens directly from Ukraine, it took near a month to arrive but worth the wait.
First I found this lens was not sharp and I can barely focus to infinity with a 'flood adapter', this is not normal for mirror lens since it has overshot infinity focus, then later I learned that, this particular lens is always over tightened during assembly to cause the mirror to deform a bit. There is a simple instruction on the internet to 'relex' the mirror, I did that and completely changed things ! Now I can not only get sharper image, but also able to focus to infinity with room to spare, need not to use those flat m42 adapter that hard to remove and install.

I would rate this lens on par if not better than the Tamron 55BB, the only complaint is the focus ring quite stiff to turn especially in cold weather, and relub the lens is not easy, due to the tiny screws used to fix the tubing that easy to crack so I did not do that.
New Member

Registered: June, 2016
Location: Le Mans, France
Posts: 4
Review Date: October 24, 2021 Recommended | Price: $75.00 | Rating: N/A 

Pros: Very sharp lens even compared to my Tamron SP 500mm f/8 55BB
Cons: none @ this price
Sharpness: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Pentax K-5   

Hi :

I was on a business trip to Baku, Azerbaijan, some 10-years ago, losing myself in some flea markets looking for the USSR's usual stuff, binos, lenses ... and Matrioskas on a Saturday-afternoon. Jumped on this 500mm in mint-condition, as brand-new, the asking price was $150 ... however I hardly negotiated to walk away with it for $75.
Mine is the 3M-5CA, identical to the one in the 4th picture.

I was not able to try it once back home as I was not in possession of any original Pentax M42 adapter, and hell, I thought to be already very well equipped with my Tamron SP 500mm 55BB, so I did not bother for years. Lately, I got my hands on some NOS Pentax M42 adapter @ abt. $20 each so I decided to give to the Russian's made tank a chance...

I should have done that before! It blows the 55BB away @ least within my shooting environments: birds and leaves with the use of a tripod. Soo easy...

The cormorants are lazing on the little islet we see on the landscape shot taken with the Pentax DA 35mm f/2.4 AL, the huge crop is from the full W/H taken with the 3M-5CA 500mm. Zero PP. Custom image set to Vibrant, except the one shot with the 35mm which was set to Landscape.

So do not hesitate to buy it if you jump on a specimen in good working condition!

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New Member

Registered: April, 2018
Location: Larissa
Posts: 2
Review Date: April 14, 2020 Recommended | Price: $60.00 | Rating: 9 

Pros: Very sharp lens
Cons: Difficult to handle
Sharpness: 9    Aberrations: 10    Bokeh: 8    Handling: 6    Camera Used: Pentax Q   

Very sharp lens I used them for video
New Member

Registered: February, 2016
Location: Pisz, Poland
Posts: 1
Review Date: September 16, 2017 Not Recommended | Price: $70.00 | Rating: 5 

Pros: bokeh
Cons: value
Sharpness: 6    Aberrations: 5    Bokeh: 10    Handling: 5    Value: 8   

Veteran Member

Registered: October, 2014
Location: Washington
Posts: 2,176
Review Date: January 20, 2017 Recommended | Price: $125.00 | Rating: 9 

Pros: Sharp and relatively easy to hand hold
Cons: heavy
Sharpness: 9    Aberrations: 10    Handling: 5    Value: 10    Camera Used: k3   

I had a Sigma 600mm mirror. There is no comparison. The 3m-5a is a close to a conventional lens as you can get. The image attached is my standard test shot hand held. It shows shadow detail, highlight detail, ca, contrast and bokeh. I am amazed at how this lens performs. The contrast is a little low but nothing you can't correct in any program. It is a keeper!

IMGP3772 by teamrimfire, on Flickr
New Member

Registered: March, 2014
Posts: 12
Review Date: March 5, 2014 Recommended | Price: $180.00 | Rating: 8 

Pros: the optics are first class-best mirror i have ever used.
Cons: 4 meters minimum focus, clearence issues with some D slrs's
Sharpness: 9    Aberrations: 9    Bokeh: 5    Handling: 6    Value: 9    Camera Used: Nikon D7000   

Read about these lenses here, and made me want to try one. Just did my first images with it, and although the keeper rate is still low (not unusual for a 500mm anything) there are enough stellar shots that its a keeper already. total freedom from CA's, and very good color and contrast for a mirror lens, or any lens. here are a couple of shots i took with it today
Veteran Member

Registered: June, 2013
Location: Sunny Dun(ny)fermline, Fife
Posts: 405
Review Date: July 16, 2013 Recommended | Price: $80.00 | Rating: 8 

Pros: Capable of pretty sharp results
Cons: the weight and the fixed aperture
Sharpness: 8    Aberrations: 9    Bokeh: 4    Handling: 5    Value: 10   

Bought this as a means of trying my hand at telephoto before I splash out on an expensive lens. I had a 500mm f8 mirror lens before (a Centon) which I absolutely hated. Having read reviews here I feel the general consensus is that a good mirror will not be as good as a good regular lens so I can assume that the MTO is a good example of a mirror lens because I think the results are quite sharp.
The build is very solid and the lens is substantially bigger and heavier than the Centon that I hated so much.
The lack of aperture control is a source of frustration but I think the lens can be got at a terrific price and ultimately if you move on you would probably recoup your costs when selling on
Forum Member

Registered: October, 2010
Location: Klaipeda
Posts: 77

1 user found this helpful
Review Date: November 14, 2011 Recommended | Price: None indicated | Rating: N/A 


This is Russian made lens
New Member

Registered: September, 2011
Posts: 2
Review Date: September 23, 2011 Recommended | Price: $160.00 | Rating: 9 

Pros: Optical quality, comstruction
Cons: Weight

It is a solid, well built, and optical quality is excellent for being a mirror lens,
I own several mirror lenses (none more expensive than 400 $) including other MTO's and the Tamron 500 f8, and this is the best performer.
I am amazed by the total lack of aberration.
It is a tripod-only lens (1,2 kg),
Veteran Member

Registered: November, 2009
Location: Iowa
Posts: 2,275
Review Date: May 6, 2011 Recommended | Price: $100.00 | Rating: 9 

Pros: Size, weight, good image quality, no CA or PF
Cons: Fixed f:8 aperture

After using several mirror lenses for wildlife & bird photography, I picked up one of these from a fellow forum member. I was about to give up on mirror lenses, but I thought I'd give it just one more go. Since it's a widely held opinion that the two best mirror lenses are the 3M and the Tamron SP, (with a slight edge in performance given to the 3M) I confined my last-ditch mirror lens purchase to one of those.

With other mirror lenses, I was always dissapointed with the image quality. Poor detail rendering, washed-out colors, and low contrast tainted my opinion of what a mirror lens could do. I wasn't too optimistic when I screwed my new acquisition onto my trusty *ist DS and took a few test shots of mundane objects in my yard. I was stunned to find a handheld shot of a weathered shed door revealing a surprising level of detail that other mirror lenses failed to show. Every grain and blemish on the wood, and every speck of rust on the padlock were tack sharp, even at full resolution. A random shot of tree bark showed equally crisp detail and excellent contrast. Colors were also much more vivid than any other mirror lens I tried. It had the usual mirror lens "donut" bokeh, but it was smoother and less distracting than with other mirror lenses I've tried.

In fact, I would rate the overall image quality as comparable with my Tamron SP 60-300mm zoom, which is no slouch. To make a long story short, this one's a keeper! The only reason I'm not rating it a "10" is because it's a fixed aperture f:8 design, which really is a non-issue for me.

I used to lust after a Bigma... Not so much anymore. In fact, I'd be willing to bet that if I had a Bigma, I'd still use this one more.

Here are a few test shots I took with it:

I just took these as quick & dirty test shots. Nothing fancy. All were taken at ISO 800 (which accounts for the grain), handheld, with an *ist DS body.

And here's a direct comparison of the 3M vs. Tamron SP, with test shots:

In the above comparison, the Tamron shots look good, but I think the shots taken with the 3M have just a bit better contrast.

On mounting this lens to a Pentax DSLR: There are at least two versions of this lens. The one pictured (the earlier 3M-5A-MC) has a retractable lens hood, tripod collar, and is a larger diameter than the one I have (the later 3M-5CA model). Mine lacks the retractable hood and tripod collar, so it's smaller. My copy is an M42 mount. I use a cheap, flanged (non-infinity focusing) M42 to PK adapter from eBay (around $6) for this lens. On a conventional lens, the flanged adapters don't allow infinity focusing, but since mirror lenses focus past infinity anyway, the cheap adapter allows infinity focusing with no problem. When mounted to either my *ist DS or K100D, the rear edge of the lens barely clears the overhang of the pentaprism... just enough to work. Other Pentax DSLRs have less of an overhang, so it would be even less of a concern on those cameras. If you're considering buying this lens for an *ist DS or K100D, look for the 3M-5CA version like mine, without the retractable hood or tripod collar. Otherwise, mounting could be a problem. I basically converted mine to a PK mount by screwing the adapter onto the lens very tightly with a PK rear lens cap. It's tight enough that it prevents the adapter from unscrewing from the lens when dismounting the lens. Pretty slick. The cheap flanged adapters also have a lens locking pin slot that locks the lens to the camera just like a conventional PK mount lens, so that's also a plus.

If you want a good mirror lens, this (or the Tamron SP) is the one to go with.
Add Review of MTO500 / 3M-5A / 3M-5CA / ZM-5A maksutov mirror 500mm F8

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