• BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

    Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

Interview with Harpia Team Leader (1 Viewer)

Troubador

Moderator
Staff member
Supporter
So true!
Still, the Zeiss name plus the extra wide field will ensure it is considered. Imho, it will be the scope to beat if the view is comfortable and the QC is Zeiss grade.
The ball peen hammer QC method pioneered by the founder should be highlighted and still honored by the firm. It helped make them a world leader then and it has even more power today in a world of second rate 'almost as good' stuff.

The view was certainly comfortable through the pre-production prototypes but I am keeping my powder dry until I have looked through a genuine full production off-the-shelf unit. It sounds terrific but lets wait and see........

Lee
 

Sagittarius

Well-known member
Hello, Lee.
Long time no talk.
Hope you are doing well.

Good to see this interview.
It's appreciated, greatly! :t:

Was especially glad you asked Mr Dobler why there was no straight version and disappointed to find out there doesn't seem to be one forthcoming. :-C
The statement that 90% of spotting scopes ordered are angled is not what I would have guessed and was very surprised to read that. :eek!:

That just about eliminates the chance I will own a Harpia, unfortunately.
But it's good to know what not to expect so I'm still grateful for the interview. |=)|
 

Hauksen

Forum member
Hi,

Was especially glad you asked Mr Dobler why there was no straight version and disappointed to find out there doesn't seem to be one forthcoming. :-C
The statement that 90% of spotting scopes ordered are angled is not what I would have guessed and was very surprised to read that. :eek!:

I found that very interesting, too. If I remember correctly, the keeper of the German Juelich-Bonn forum years ago pointed out that the majority of the big scopes he sold in his shop were angled, but the majority of the smaller scopes (like 65 mm) were straight, because so many people like to use the small scopes from car windows.

Of course, that was the breakdown for his customers in Germany ... usage patterns might be different elsewhere. Still, it's consistent with Dobler's perspective, and Dobler actually adds a plausible reason for the preference for angled big scopes, which my old explanation lacked.

Regards,

Henning
 

Troubador

Moderator
Staff member
Supporter
Hello, Lee.
Long time no talk.
Hope you are doing well.

Good to see this interview.
It's appreciated, greatly! :t:

Was especially glad you asked Mr Dobler why there was no straight version and disappointed to find out there doesn't seem to be one forthcoming. :-C
The statement that 90% of spotting scopes ordered are angled is not what I would have guessed and was very surprised to read that. :eek!:

That just about eliminates the chance I will own a Harpia, unfortunately.
But it's good to know what not to expect so I'm still grateful for the interview. |=)|

Hi Saggi
Good to hear your voice again.

Over here in the UK I can't remember the last time I saw a straight scope. Angled means group viewing is much easier. Taller folks have to bend a bit lower is all.
As for you, why don't you try this? Rotate the Harpia in its tripod ring so that its eyepiece is parallel to the ground. You can aim it in the usual way (there is gunsight on the sunshade so you can rotate this to suit you) and you would look into the eyepiece from one side. but not by too much. You would completely avoid the 'looking down' of a conventional angled scope position.
Dobler uses this a lot when sitting down alongside his lowered tripod.

Lee
 

Troubador

Moderator
Staff member
Supporter
Hi,



I found that very interesting, too. If I remember correctly, the keeper of the German Juelich-Bonn forum years ago pointed out that the majority of the big scopes he sold in his shop were angled, but the majority of the smaller scopes (like 65 mm) were straight, because so many people like to use the small scopes from car windows.

Of course, that was the breakdown for his customers in Germany ... usage patterns might be different elsewhere. Still, it's consistent with Dobler's perspective, and Dobler actually adds a plausible reason for the preference for angled big scopes, which my old explanation lacked.

Regards,

Henning

Henning

If you rotate the Harpia within its tripod ring, set on a window clamp, you can use it OK within a vehicle. The video referred to earlier in this thread illustrates this technique.

Lee
 

Hauksen

Forum member
Hi Lee,

If you rotate the Harpia within its tripod ring, set on a window clamp, you can use it OK within a vehicle. The video referred to earlier in this thread illustrates this technique.

I'm sure it works, but it looks a bit inconvenient to me, so I'd understand why people would buy straight scopes for use from cars.

Since you mentioned the use of sights, it would be very interesting (to me, at least) what Dobler thinks about reflex sights on spotting scopes.

He actually has two sight-related patents to his name:

https://patents.google.com/?inventor=Gerold+Dobler

It has always been a bit perplexing to me that Zeiss offers both spotting scopes and reflex sights, but doesn't go the small step of making their scopes capable of accepting the reflex sights. To me, that looks like a missed opportunity to generate extra sales while advancing the state of the art.

Regards,

Henning
 

Troubador

Moderator
Staff member
Supporter
Hi Lee,



I'm sure it works, but it looks a bit inconvenient to me, so I'd understand why people would buy straight scopes for use from cars.

Since you mentioned the use of sights, it would be very interesting (to me, at least) what Dobler thinks about reflex sights on spotting scopes.

He actually has two sight-related patents to his name:

https://patents.google.com/?inventor=Gerold+Dobler

It has always been a bit perplexing to me that Zeiss offers both spotting scopes and reflex sights, but doesn't go the small step of making their scopes capable of accepting the reflex sights. To me, that looks like a missed opportunity to generate extra sales while advancing the state of the art.

Regards,

Henning

Henning

The rifle sights I referred to are just two ridges with a groove between, moulded onto the sun shade.

To attach a reflex sight would need something like a short Picatinny rail and I can see that creating a flat surface for this would be an added cost to the optical tube. And the sight would need to be elevated above the height of the angled eyepiece to get a straight view through it which would mean no possibility to use normal bare-eyeball glancing over the length of the scope and some birders would not like this at all.

Nevertheless I will ask his opinion on this.

Lee
 

Hauksen

Forum member
Hi Lee,

And the sight would need to be elevated above the height of the angled eyepiece to get a straight view through it which would mean no possibility to use normal bare-eyeball glancing over the length of the scope and some birders would not like this at all.

Nevertheless I will ask his opinion on this.

Thanks a lot!

Dobler's sight mount patent actually integrates the mount very elegantly into the scope, so he certainly has been looking for solutions.

(Personally, I tend to favour a laterally offset sight. The Vortex Viper actually allows mounting one of these. It appears Bushnell offers a sight with provisions for a rail too, but apparently, that's marketed towards hunters. The Swarovski STR 80 targeting the same market actually comes with a rail, though it's not installed on most pictures of the scope you find online.)

Regards,

Henning
 

Troubador

Moderator
Staff member
Supporter
Hi Lee,
Thanks a lot!

Dobler's sight mount patent actually integrates the mount very elegantly into the scope, so he certainly has been looking for solutions.

(Personally, I tend to favour a laterally offset sight. The Vortex Viper actually allows mounting one of these. It appears Bushnell offers a sight with provisions for a rail too, but apparently, that's marketed towards hunters. The Swarovski STR 80 targeting the same market actually comes with a rail, though it's not installed on most pictures of the scope you find online.)

Regards,

Henning

And Henning, it would be cheaper to incorporate the base plate for the attachment of the sight or at least the Picatinny rail or similar, to the tripod ring.

Lee
 

Troubador

Moderator
Staff member
Supporter
Henning Herr Dobler agrees that a reflex sight could be useful with some scopes in some circumstances. He would not recommend one with Harpia as the low magnification and wide field of view makes target acquisition quite easy.
We can imply from this that he considers a reflex sight would be useful in scopes with narrow fields of view.

Lee
 

Hauksen

Forum member
Hi Lee,

Henning Herr Dobler agrees that a reflex sight could be useful with some scopes in some circumstances. He would not recommend one with Harpia as the low magnification and wide field of view makes target acquisition quite easy.

Thanks a lot, that was amazingly quick!

I see his point about the Harpia, and the technique for observing flying birds by zooming out and letting them fly through the field of vision he described in your interview in fact seems to match the strengths of the Harpia well.

Regards,

Henning
 

Sagittarius

Well-known member
Hi Saggi
Good to hear your voice again.

Over here in the UK I can't remember the last time I saw a straight scope. Angled means group viewing is much easier. Taller folks have to bend a bit lower is all.
As for you, why don't you try this? Rotate the Harpia in its tripod ring so that its eyepiece is parallel to the ground. You can aim it in the usual way (there is gunsight on the sunshade so you can rotate this to suit you) and you would look into the eyepiece from one side. but not by too much. You would completely avoid the 'looking down' of a conventional angled scope position.
Dobler uses this a lot when sitting down alongside his lowered tripod.

Lee


Lee, I will, definitely, give your suggestions a try when I get the chance to view the Harpia in person.
Thanks for your reply and input. :t:
 

elkcub

Silicon Valley, California
United States
Very interesting interview, Lee.

I couldn't help but wonder about Dobler's rather curious comment:
...This gave a magnification of 26x and an exit pupil of 2.4mm which was found to be very effective because the human eye is best able to perceive details when the pupil is between 2 and 2.5mm. By the way, Holger Merlitz mentions this fact several times in his recent book although the principal was first mentioned by König and Köhler in 1959.

Actually, the principle (i.e., experimental findings) was first mentioned long before 1959, and has its origins in the late 19th century. A paper by Cobb (1915) "THE INFLUENCE OF PUPILLARY DIAMETER ON VISUAL ACUITY," is referenced by several authors including Selig Hecht in 1927. I've also found it referenced in Southall's 1937 "Introduction to Physiological Optics".

Ed :brains:
 
Last edited:

Troubador

Moderator
Staff member
Supporter
Very interesting interview, Lee.

I couldn't help but wonder about Dobler's rather curious comment:


Actually, the principle (i.e., experimental findings) was first mentioned long before 1959, and has its origins in the late 19th century. A paper by Cobb (1915) "THE INFLUENCE OF PUPILLARY DIAMETER ON VISUAL ACUITY," is referenced by several authors including Selig Hecht in 1927. I've also found it referenced in Southall's 1937 "Introduction to Physiological Optics".

Ed :brains:

Thanks Ed I know he will be very interested in those references. Clearly 'Ed' stands for 'educated' .

Lee
 

kabsetz

Well-known member
Lee,

Thanks for the interesting and well thought out interview. It was valuable to get facts and design philosophy from a knowledgeable source, and quite fascinating to compare what Herr Dobler says to what could be conjured out of an early sample through pedestrian analysis techniques. I was happy to notice that what I'd posted last august was essentially confirmed here.

Rather than link my previous posting, I'm re-posting relevant bits here, but the original post is on page 5 of the Harpia thread.

"In august 2017 I had a first look at the Harpia 95 and did some experiments with exit pupil sizes at different zoom settings. The method used was to center a spot of light in the field of view, and then use a variable width rectangular obstruction centrally in front of the objective, looking for the widest obstruction that would still let me see the full field of view, i.e. the central spot. If the obstruction was any wider, a vertical shadow would appear in the center of the image, widening as the obstruction would be widened. If the obstruction is narrowed from this limit width, the image becomes progressively brighter.

Results were rather interesting. Firstly, they support the notion that the zoom vignettes at low magnification zoom settings. Secondly, the vignetting is not linear by any means, but much more pronounced at low magnifications.

Here's the list:

Zoom setting 1x, magnification 23x: clear aperture > 55 mm.

Zoom setting 1.25x, mag. 29x: clear aperture ca. 70 mm.

Zoom setting 1.5x, mag. 35x: clear aperture ca. 80 mm.

Zoom setting 1.75x, mag. 40x: clear aperture ca. 90 mm.

Zoom setting 3.0x, mag. 70x: clear aperture ca. 93 mm.

Zeiss exit pupil specifications are given only for the end magnifications, and assuming correct and exact figures for both exit pupil and magnification, yield 57.5 mm clear aperture at 23x (1x zoom) and 93.8 mm clear aperture at 70x (3.0x zoom).

These clear apertures mean that if fitted with an eyepiece that would give, say, a range from 30-90x, the scope would be a 30x57, but at 37.5x it would already be 70 mm scope and at 45 x an 80 mm scope, which does not sound too bad at all. At any magnification above about 1.75x base magnification, it is near enough to its nominal 95 mm aperture that the difference hardly matters much."

So a simple shoestring method gave essentially correct results at the data points provided by Herr Dobler. Thus we can assume that the experimental results for 1.25x and 1.5x magnifications are probably pretty accurate as well. This is of value when considering the use of higher magnification eyepieces. My guess is that the 95 mm Harpia would work decently well up to 40-120x magnification range, where it would be a 60x80 mm scope in the mid-low range.

Incidentally, the method I describe here can also be used to determine your eye pupil when viewing with binoculars that have exit pupils larger than your eye pupil at the light levels where testing is done.

Kimmo
 

Binastro

Well-known member
The question still remains as to whether all production Harpias would give really sharp images at 120x.
This is because I think that it would be difficult with a complex objective to achieve good enough quality control for all of them to be sharp at 120x.
 
Last edited by a moderator:

kabsetz

Well-known member
Binastro,

Fair question. From experience, no current scope is made to strict enough standards for all production units to give really sharp images at 120x, but the best models have a fair number of units coming out that do. Its pure speculation from my part, but I suspect that this is the reason production has been delayed this long.

Once the actual retail units hit the shelves, I'll do some testing.

Measured with callipers, the diameter of the exposed front lens of my ATX 95 is 94,85 mm. The filter thread inside diameter measures 95,8 mm.

Kimmo
 

Binastro

Well-known member
Thanks Kimmo,

With astro scopes the convention used to be that diameter was the actual objective diameter without its cell, and aperture was the actual clear aperture.

The 3 inch Starboy is actually 73mm aperture.
Also there were extra fine objectives, which cost more than regular, which was all I could afford in 1957.
In addition the maker would rotate the two elements to best position by eye and pencil mark this.
Over the years the two halves were well out of best position.

With camera lenses, these are usually also slightly smaller than one would think.
Nikon, Zeiss, Canon and Minolta were usually slightly larger than independents.

I haven't relooked at the new 23 element Sony 400mm f/2.8 lens but this may take something from Wall's zerochromat or Hyperchromat? ideas to use a less complex front group and compound rear groups to drastically reduce weight.
These are made to order and $12,000 doesn't sound too much if they perform as advertised.
 
Warning! This thread is more than 4 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Top