• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Pentax 100 ed Spotting Scope? (1 Viewer)

Getting back to the Pentax 100 ed spotting scope. I was able to do a side by side comparison between the Pentax 100 ed spotting scope and the Pentax 80 ed spotting scope and I wasn't able to, with my visual acuity, notice a big enough difference between the optics of the two scopes. I used the same Pentax 20-60 zoom eyepiece for each scope and fixed on the same object at various distances. The difference was so marginal that I felt the added weight and bulk and especially the added costs (approx $400) didn't warrant my buying the 100 ed scope. So I purchased the 80 mm ed. I know later on I won't look back and doubt my decision especially when I'm hauling a much lighter scope into the field. Also, I used several fixed size eyepieces with similar results. All eyepieces were Pentax products. Now, I need to do some research to find the proper setup so I can do some photography using the 80mm. I have an Olympus C 750 digital camera with a fixed zoom (the lense dosen't come off) that I would like to adapt to it. Does anyone have any suggestions?
 
Last edited:
Rick and Henry,

I have at one point measured the true apertures of both the Nikon ED 82 A and an Opticron ES 80 GA ED, which although having a somewhat different objective lens configuration (according to Opticron) probably has the same prism housing design and focusing prism. I only measured at roughly infinity focus, at which I got ca. 78-79mm for the Opticron but 82-83mm for the Nikon. I used a variant method taken from J.C. Bouguet, where you place a card in front of the objective and adjust the width of the card until you just begin to see light simultaneously leaking past both sides of the card when you examine the exit pupil from a comfortable distance. When I have tried this method I have found it quick and very repeatable as well as easy to read to a precision of a mm. or less. So, I suspect that Rick's measurements may be a bit to the low side of true. Of course, I'm open to criticism as to the accuracy of my measurements, but the method is so simple that if Rick is not completely fed up with measuring his scopes, he could try to duplicate.

Concerning the zooms, I find it interesting that S. Ingraham was so enthusiastic over the Pentax. I have not tested it as thoroughly as Henry, but my experience was also rather underwhelmed.

Kimmo
 
So my bad experience with the 100 mm wasn't unique. As Ultra Lite's photos show there are some good examples of the Pentax. I don't have one though. I had heard that quality control was spotty so as I said I'll get mine checked . Neil.
 
Getting back to the Pentax 100 ed spotting scope. I was able to do a side by side comparison between the Pentax 100 ed spotting scope and the Pentax 80 ed spotting scope and I wasn't able to, with my visual acuity, notice a big enough difference between the optics of the two scopes. I used the same Pentax 20-60 zoom eyepiece for each scope and fixed on the same object at various distances. The difference was so marginal that I felt the added weight and bulk and especially the added costs (approx $400) didn't warrant my buying the 100 ed scope. So I purchased the 80 mm ed. I know later on I won't look back and doubt my decision especially when I'm hauling a much lighter scope into the field. Also, I used several fixed size eyepieces with similar results. All eyepieces were Pentax products.

As the owner of both the 100mm and 80mm Pentax scopes and four astro scopes I agree with this conclusion completely with this qualification - for normal real world terrestrial visual (not photographic) use. Normal air turbulence limits you to about 60-70x anyway no matter what scope you are using. This is assuming you need the high magnification because the target is at a great distance.

Strangely the 100mm comes into it's own when used close in. For instance I was observing nesting birds at about 300 feet with two others both with Swaros and 60x zooms. We were trying to sex the chicks in the nest. So I put in the 6mm TMB ep (about 100x) and the amount of additional usable detail compared to the 60x swaros was very obvious. Why? Because at 300 feet that 100mm objective had no air turbulence to deal with.

Another case in point:
This summer I had the use of a Pentax - 105 SDP - a $4000 plus scope.

This one:
http://www.optcorp.com/product.aspx?pid=1-600-1038-8728

I had a weekend to compare them to my other scopes for visual use out on my deck. Looking at some bay ducks about two miles out in the main channel of the river there was virtually no practical advantage over my other scopes for the reasons posted above. BTW this was using this scope with no prism just a 60mm extension tube. Of course I did not get a correct image this way but I could judge the over-all image quality well enough.

However set up the Pentax 105 SDP for prime focus photography (about 20x) and take shots of the feeder birds at 30 feet and the advantages of the superior optics was obvious - no CA, no field distortion, superior contrast and absolutely tack sharp resolution across the entire FOV. It produced the most vivid bird shots I have ever taken. The glass just got out of the way and the images really looked like you were only 5 feet away from the birds. A class act.

Anyway my opinion is that for visual birding any number of decent 80mm scopes will get the job done and I wouldn't get too bent out of shape over the minutia of the optics involved.

Get out in the field and look at birds not the hardware.
 
Last edited:
Thank you for confirming my suspisions about the two scopes and the great advice. What would you recommend for a camera adapter? "(I have an Olympus C 750 digital camera with a fixed zoom (the lense dosen't come off) that I would like to adapt to it. Does anyone have any suggestions?)"
 
Thank you for confirming my suspisions about the two scopes and the great advice. What would you recommend for a camera adapter? "(I have an Olympus C 750 digital camera with a fixed zoom (the lense dosen't come off) that I would like to adapt to it. Does anyone have any suggestions?)"

Can't help you. I don't use a PS camera - don't "digiscope".

One of my typical setups...
 

Attachments

  • 80mm2.jpg
    80mm2.jpg
    99.1 KB · Views: 276
FWIW, I have an all-Pentax digiscoping set consisting of the PF80ED, the 8.5/12mm XF and XF Zoom eyepieces, the PF-DS1 digicam adapter and an Optio S5z 5mp digicam. This is about the smallest, lightest rig you can put together I think.

I use the XF Zoom for visual and the fixed focal lengths for digiscoping. The camera itself is about 4yrs old with an excellent user interface for digiscoping including live histogram. And because you can get insane focal lengths with this setup, cropping is not necessary so 5mp is enough for most shots.

When I pulled the scope out storage to test its clear aperture last week I snapped a few pics from my veranda here in downtown Tokyo. Weather conditions were poor and misty with light breeze and the concrete veranda can vibrate from nearby condo tower construction and traffic on the elevated expressway. These are straight from the camera with no processing other than resizing.

The pidgeons were perched an expressway support: distance 75.5m-fl4410mm-F8.9-ISO200-1/60sec/EV-0.3

The small bird is a very nervous type that is in constant motion: distance 10.5m-fl3696mm-F7.8-ISO200-1/40sec/EV-0.3

The plant served as a fixed target for overall sharpness.
Pic 1 distance 12.5m-fl2604mm-F5.25-ISO200-1/30sec/EV-1
Pic 2 distance 12.5m-fl6195mm-F12.5-ISO200-1/6sec/EV0

Rick
 

Attachments

  • 013 (800x600).jpg
    013 (800x600).jpg
    100.8 KB · Views: 161
  • 007 (800x600).jpg
    007 (800x600).jpg
    100.4 KB · Views: 173
  • 003 (800x600).jpg
    003 (800x600).jpg
    115.4 KB · Views: 145
  • 044 (800x600).jpg
    044 (800x600).jpg
    113.8 KB · Views: 153
Here are pics of the rig. The camera LCD is fitted with a magnetically attached hood with 2x loupe. The camera w/hood, adapter and eyepiece weigh only 400g!

cheers,
Rick
 

Attachments

  • IMG_3056.JPG
    IMG_3056.JPG
    43.9 KB · Views: 131
  • IMG_3057.JPG
    IMG_3057.JPG
    38.4 KB · Views: 135
  • IMG_3058.JPG
    IMG_3058.JPG
    35.8 KB · Views: 127
  • IMG_3060.JPG
    IMG_3060.JPG
    38 KB · Views: 131
  • IMG_3062.JPG
    IMG_3062.JPG
    34.7 KB · Views: 160
I was replying to the first post...sorry for disrupting the chain. I got a videoscope from the Pentax 100ED cooking right now which I will post later.

I think it's fine, especially for low light conditions. I've posted tons of stuff in the past so didn't want to re-write everything.
 
Last edited:
I was replying to the first post...sorry for disrupting the chain. I got a videoscope from the Pentax 100ED cooking right now which I will post later.

I think it's fine, especially for low light conditions. I've posted tons of stuff in the past so didn't want to re-write everything.

It would have been useful having a link to your original testing thread as it was very comprehensive but took me some time to find it.
I'm looking forward to the video.
Neil.
 
Now that's what I call an impressive setup. Awesome!

It occurred to me that we are talking about spotters so I found some old pics of the 100mm set up with the CA-35 DSLR adapter just so you could see how it looks set up for use with a DSLR camera.

Note: since these pics were taken I have moved the red dot sight back so it is now mounted on the prism housing.
 

Attachments

  • setup 011.jpg
    setup 011.jpg
    62.3 KB · Views: 156
  • setup 016.jpg
    setup 016.jpg
    71.6 KB · Views: 156
  • setup 015.jpg
    setup 015.jpg
    82.6 KB · Views: 205
It occurred to me that we are talking about spotters so I found some old pics of the 100mm set up with the CA-35 DSLR adapter just so you could see how it looks set up for use with a DSLR camera.

Note: since these pics were taken I have moved the red dot sight back so it is now mounted on the prism housing.
Ultra Lite, You sure know how to make a guy weep with envy. That appears to be a very sound setup with straight forward equipment. It must be a joy to use. Thank you for your very useful postings.
 
Last edited:
Getting back to the Pentax 100 ed spotting scope. I was able to do a side by side comparison between the Pentax 100 ed spotting scope and the Pentax 80 ed spotting scope and I wasn't able to, with my visual acuity, notice a big enough difference between the optics of the two scopes. I used the same Pentax 20-60 zoom eyepiece for each scope and fixed on the same object at various distances. The difference was so marginal that I felt the added weight and bulk and especially the added costs (approx $400) didn't warrant my buying the 100 ed scope. So I purchased the 80 mm ed. I know later on I won't look back and doubt my decision especially when I'm hauling a much lighter scope into the field. Also, I used several fixed size eyepieces with similar results. All eyepieces were Pentax products. Now, I need to do some research to find the proper setup so I can do some photography using the 80mm. I have an Olympus C 750 digital camera with a fixed zoom (the lense dosen't come off) that I would like to adapt to it. Does anyone have any suggestions?

Now that I've had my Pentax 80mm ed spotting scope with 20x60 pentax zoom for a week or so, I thought I'd report back on my impressions. Well, in a word, awesome! The view is spot on sharp through all levels of maginifications. I am able to read 1/2" print at 100 yards crystal clear. If your goal is to magnify distant objects bright and clearly then this spotting scope more than does the job beautifully. For the price I don't know of any other scope that can do any better. In fact, I can't imagine the view being any sharper. Granted, the zoom eye piece restricts the expanse of territory that is visible because of the nature of the zoom eye piece. But, all I have currently is this eye piece and I couldn't be happier. So, if anyone is looking for a phenom. scope, for the money, the 80mm ed pentax suits the bill. Beyond the zoom eye piece, I've only drooled over an assortment of fix eye pieces, that their view provides. Incidentally, I don't work for Pentax.
 
Last edited:
The XW14 on that PF80 makes for a wide 36X view that is mighty impressive.
I'm always at a loss when I hear people finding fault with the view through these scopes. It completely contradicts my experience.

I have to admit though that I've actually never looked through the SMC zoom.
 
Warning! This thread is more than 15 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

Back
Top