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SDL v3 Eyepiece Now Shipping (1 Viewer)

Singlereed

Well-known member
Fair enough about the magnification on the 40809 eyepiece I just read what it said on the box regarding magnification, it didn’t refer to a Mm4 60 but a much older model scope, it was a very old NOS example I think. I tried it out as others sang its praises but it wasn’t for me and I returned it.
 
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miketaylor

Well-known member
Good news about the SDL v3. I'm planning on buying a MM4 60 angled scope, and mulling over the eyepiece. I currently use a SDL v2 with an old Kowa TSN-3, and am very pleased with it.

I've seen and heard comments that the SDL v2 was really designed for the larger scopes and that it is a bit heavy for the MM4 60 on a tripod (Velbon D600), and that the HDF was the better solution in terms of balance. Is this fair comment? Clearly the SDL v2 is optically better and also waterproof. What are people's experiences with this combo?

With the new SDL v3 being lighter and shorter, does this negate the above comments and make it the ideal eyepiece for the MM4 60?

Thanks.

Thanks for your responses. I have now bought the MM4 60 ED/45 with the SDL v3 eyepiece, and the combination is excellent. It works well on my Velbon Sherpa D200 tripod, and doesn't feel unbalanced. The tripod adapter actually has two 1/4" thread holes for a tripod mounting screw, so you can choose the best fitting option.

Testing the MM4 60 + SDL v3 side by side with the Kowa TSN-3 77mm + SDL v2, on a dark and dismal wet afternoon, I can hardly see any difference optically, other than the magnification (which is higher for the 77mm objective), and the MM4 60 has a wider field of view than the Kowa for the same reason.

I bought the MM4 60 for travelling (or for carrying in a backpack on my bike), but I'm wondering if I'll find that I use this much more than the heavier and larger Kowa for normal birding.

Mike
 

asp09

Well-known member
I bought the MM4 60 for travelling (or for carrying in a backpack on my bike), but I'm wondering if I'll find that I use this much more than the heavier and larger Kowa for normal birding.

Mike

You may well find that is the case. I also have a large Kowa (TSN-823), but rarely use it nowadays. Optically it is clearly superior to my MM4 60, especially in low light, but most of the time I find that the Opticron is more than good enough, and so much easier to carry around over long distances (especially as I use a lighter tripod and head).

Given that you have both the SDL v3 and v2 zooms, it would be great if you could do a comparison some time on your MM4 and report back to us! I think a lot of us would be really interested to know how they compare and whether it is worth the upgrade. But perhaps it is not easy to remove to the SDLv2 from the Kowa now that you have adapted it?
 

Gzoladz74

Well-known member
You may well find that is the case. I also have a large Kowa (TSN-823), but rarely use it nowadays. Optically it is clearly superior to my MM4 60, especially in low light, but most of the time I find that the Opticron is more than good enough, and so much easier to carry around over long distances (especially as I use a lighter tripod and head).

Given that you have both the SDL v3 and v2 zooms, it would be great if you could do a comparison some time on your MM4 and report back to us! I think a lot of us would be really interested to know how they compare and whether it is worth the upgrade. But perhaps it is not easy to remove to the SDLv2 from the Kowa now that you have adapted it?

+1 for the SDLv2 vs v3 Comparison, if possilbe :)

Funnily enough, when I got was using my MM360 less and less as it started feeling that I could not justify carrying it if the magnification was a bit short of what I needed.

I use the HR80 much more as, although heavier, once I go through the hassle of carrying a scope, I now get enough reach in most cases.

I find them both very good.
 

miketaylor

Well-known member
You may well find that is the case. I also have a large Kowa (TSN-823), but rarely use it nowadays. Optically it is clearly superior to my MM4 60, especially in low light, but most of the time I find that the Opticron is more than good enough, and so much easier to carry around over long distances (especially as I use a lighter tripod and head).

Given that you have both the SDL v3 and v2 zooms, it would be great if you could do a comparison some time on your MM4 and report back to us! I think a lot of us would be really interested to know how they compare and whether it is worth the upgrade. But perhaps it is not easy to remove to the SDLv2 from the Kowa now that you have adapted it?

I looked at doing this, but I found it difficult to remove the O-ring that I'd inserted into the end of the eyepiece to adapt the SDL v2 for the Kowa, and I didn't want to damage the O-ring. So unfortunately I can't do a comparison between the two eyepieces on the MM4.

However, as I mentioned in an earlier post, I did a side-by-side comparison between the MM4 60 + SDL v3 and the Kowa TSN-3 77mm + SDL v2, on a dark and dismal wet afternoon. I could hardly see any difference optically, other than the magnification (which is higher for the 77mm objective), and the MM4 60 has a wider field of view than the Kowa for the same reason. I didn't feel a need to buy another SDL v3 eyepiece to replace the SDL v2 that I use on the Kowa.

Mike
 

asp09

Well-known member
I looked at doing this, but I found it difficult to remove the O-ring that I'd inserted into the end of the eyepiece to adapt the SDL v2 for the Kowa, and I didn't want to damage the O-ring.

Mike

Yes, I thought this might be the case - I knew that the eyepiece needed some kind of adaptation to work on the Kowa. Thanks for trying, anyway. When I have the opportunity I'll go to my nearest optics store and compare the eyepieces side by side.
 

swn74

New member
apparent field of view

The main difference between the SDL2 and 3 is the field of view. For some reason Opticron don't quote the apparent FOV for either so I have measured them myself using this method at a range of magnifications (Kowa TSN2 which is the same as the MM4 77) https://www.cloudynights.com/topic/294115-apparent-fov-a-quick-way-to-measure/
I also looked up the manufacturer's figures for the equivalent eyepiece from some other brands (Sorry but pasting the alignment of the columns is messed up after copy pasting from Excel into the forum text box - if you copy paste them back into Excel it should then be readable).
For me this makes a big difference in the perceived FOV so upgrading to the SDL3 is worth it because at the lowest mag the SDL 2 aFOV is poor. The problem with using eyepieces to zoom is that the FOV does not increase proportionally when zooming out, which for me defeats the purpose of zooming out. A zoom mechanism in the body avoids this as the aFOV remains constant so the true FOV changes proportionally with magnification. I know of only two field scopes that do this (Swarovski ATX/STX and Zeiss Victory Harpia) which are both outside my price range. Does anyone know of a lower priced scope that zooms with the body?

mag true fov apparent fov apparent fov
manu specs measured
Opticron SDL2 18 1.8 35
25 47
36 58
54 1.2 68
Opticron SDL3 18 2 41
25 55
36 61
54 1.3 72
Swarovski 20-60 ATS/STS 80
20 2.1 40
60 1.1 65
Kowa TSE TE 9Z 20 1.9 38
60 1.4 56
Leica apo televid 77 20 2 38
60 1.2 72
Nikon MEP 20-60 20 2.1 40.4
60 1 54.3
 

eitanaltman

Well-known member
Can you clean up the formatting on the data? I can't make sense of it the way it is right now :/

Perhaps wrapping the "code" tag around the table will let it format properly?

It looks to me like you're saying that at 18x, the v2 has a 1.8 degree TFOV and a 35 deg AFOV, whereas the v3 ups that to 2 degrees / 41 degrees?

And at 54x (max mag), the TFOV has gone from 1.2 to 1.3 degrees and the AFOV has gone from 68 to 72 degrees?

What are the numbers in the middle? AFOV at intermediate magnifications (e.g. at 25x the v2 was 47 deg AFOV and the v3 is 55 degrees?)

I'm really interested in this info as I have the v2, and I hate the poor AFOV at low mag. As you note, it totally defeats the purpose of the extra low range in the mag scale (other than a bit bigger exit pupil I guess), on my MM60 the TFOV is basically the same at ~20x as it is at 15x. Given that limitation it seems like it would have been better to not go for a full 3x zoom range and the resultant compromises since the last stretch doesn't really bring any benefit.
 
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asp09

Well-known member
Swn74, many thanks for taking the time to post this information - this is really helpful. I’ve interpreted the table in the same way as Eitan. I must admit the figures don’t mean much to me in themselves, but from what you say, the difference is actually very noticeable in practise. This will definitely motivate me to make the drive to my nearest optics store to try it out.
 

Gzoladz74

Well-known member
Thanks Swn74 for going through the effort of doing this. My interpretation is that you are comparing FOV from the lowest to the highest mag.

It would be good if someone from Opticron could confirm this.

Opticron SDL2
x18 = 1.8
x54 = 1.2

Opticron SDL3
x18 = 2
x54 = 1.3

Swarovski 20-60 ATS/STS 80
x20 = 2.1
x60 = 1.1

Kowa TSE TE 9Z
x20 1.9
x60 1.4

Leica apo televid 77
x20 = 2
x60 = 1.2

Nikon MEP 20-60
x20 = 2.1
x60 = 1
 

swn74

New member
Table attached

I have attached the original table as a word doc. I also created a second table set out differently that some may find more useful. The main thing is to compare apparent field of view at the same magnification. This is the angle of light that hits the eye, rather than true field of view which is the angle of light coming from the subject collected by the telescope, which is what really causes annoyance.
 

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eitanaltman

Well-known member
Thank you, I attached a screen clip of the table as an image so people don't have to download the Word doc file.

The increase in AFOV looks most generous at lower magnification, which is good because that's exactly where the SDL zoom was really below par.

The jump from 35 to 41 at 18x and from 47 to 55 at 25x works out to a ~17% increase at low magnification. At the upper end it's only ~5%, but that's less of an issue because the AFOV was already quite good at higher mags.

Assuming these AFOV figures translate to the 60mm body, that makes the lower end much more enticing to use. I think my 60mm MM3 is at its best in the 20-30x magnification range for general use and having that range be 55-60deg AFOV is a really nice boost.
 

Attachments

  • Screenshot 2020-09-20 150529.jpg
    Screenshot 2020-09-20 150529.jpg
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Singlereed

Well-known member
I bought this eyepiece with a new MM4/60 but I did try it on the 77 model and if anything slightly preferred the view on the 60. I would have considered buying the 77 but actually didn’t like it as much. The added portability and lower price were also a plus. I did try the cheaper (HDF?) eyepiece which was nowhere near as good to look through, at least to my eyes. What I can’t say is how it compares with V2 or indeed any other scope. I have not regretted my purchase, it has worked well in the field so far. It has a great feel of quality, too with a positive zoom and eyecup adjustment.
 

eitanaltman

Well-known member
If the 77 didn't look better than the 60 then you had a bad sample of the 77.

I've had the 60mm MM3 for a few years now, and once a year I get to compare scopes at the local bird fair. Opticron has a presence and they let people take the scopes outside to set up and compare side by side.

I had the my 60mm MM3 alongside the 77 MM4 (plus several other scopes like Razor HD 85 and Kowa 553, 773, and 883) and the 77 gave the same quality of view, just brighter and higher mag. It's literally the same scope with a longer/larger objective tube, so assuming equal sample quality the view should be equal other than the inherent advantages of the larger objective + longer focal length. I particularly noticed a difference at high magnification, where the tiny exit pupil and smaller objective make it a bit of a struggle at the top end (35-45x), whereas the 77 is much more comfortable.
 

Gzoladz74

Well-known member
I bought this eyepiece with a new MM4/60 but I did try it on the 77 model and if anything slightly preferred the view on the 60. I would have considered buying the 77 but actually didn’t like it as much. The added portability and lower price were also a plus. I did try the cheaper (HDF?) eyepiece which was nowhere near as good to look through, at least to my eyes. What I can’t say is how it compares with V2 or indeed any other scope. I have not regretted my purchase, it has worked well in the field so far. It has a great feel of quality, too with a positive zoom and eyecup adjustment.

Thanks for the feedback - hopefully someone will be able to compare the v2 vs v3 side by side.

In the meantime, it would be great if Opticron could make available the tech specs of both eyepieces and FOV(s) in their scopes.
 

bcskr

Well-known member
What is the official outside diameter of the SDLv3? I am having a lot of difficulty getting the right fit for the new EP using my Phoneskope case and adapter.
 

Singlereed

Well-known member
This is the Phoneskope adaptor I got for the SDLv3 C-3-C07-A) PSK C-3 Adapter for Opticron SDL v3, HR3, Zeiss Gavia & Celestron Regal M2 Item Number C-3-C07-A
 

Baltimore

Well-known member
Thanks for the feedback - hopefully someone will be able to compare the v2 vs v3 side by side.

In the meantime, it would be great if Opticron could make available the tech specs of both eyepieces and FOV(s) in their scopes.
Leaving all the technical figures aside does anybody know if the V3 gives a noticeable difference over the V2 on sharpness, saturation etc when using in the field?
 

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