Celestron Regal F-ED65 (1 Viewer)

BCTD,

No problem at all answering the questions. This is actually one of my favorite parts to this hobby...finding a new product that performs way above expectations.



To answer some of your questions....they appear to be the same eyepiece...and, yes, with identical eye relief specifications...14 mm at 48x on the 65 mm. I can detect no difference physically between the two eyepieces. I finally found the digital camera and took some pictures. The first one I am going to include with this post is of the three eyepieces. The second picture will be of the three scopes and the last one was a handheld digiscoped shot (..have to find my large digiscoping adapter) through the 65 mm of an Indigo Bunting at approximately 20 yards. None of the pics were adjusted except to resize to fit in the forum. Some detail was lost because of this. Take note of the brightness, color representation and lack of CA in the Indigo bunting image (ignore the sharpness and "noise" as that is the fault of my digital camera and handheld "technique. )

To answer your question about the zoom tension....I would call it "perfect" on both scopes. It has that smooth "metallic" feel of precision parts moving together. It is firm enough not to move accidentally and yet moves freely enough when pressure is applied. Better mechanics than any of my previous zooms including the Baader clone.

Scope comparison pic...

Indigo Bunting

Ok, I found my large universal digiscoping adapter and decided to play a little in the backyard. I wanted you folks to see what I see in terms of color, brightness and the lack of color fringing in the image. Here is a shot of some of those beautiful purple flowers I mentioned earlier. The shot was taken at about 15 yards with the 80 mm Regal F-ED and the camera set at 2x....ISO 200, F4.8 1/125 speed.

FrankD: Flower's are fantastic. I'm not into digiscoping, but that's an excellent photo. I can not believe Celestron's attention to details. From printing correct magnification ranges on the ep to body color (preventing scope internal thermal issues) to course/fine focusing to image quality. Someone has certainly paid attention. Finally a spotting scope listing for $500, selling for $420 that's not a sham. I've got to find one to look through! Thanks again!

Hi Frank, Thanks for the pictures, I esp. like the flowers. I reread this thread and looked online and I was wondering as these are angled scopes do they have click stop rotation for different viewing angles like Pentax, Nikon etc. ?
Regards,Steve

Glad to help BCTD. If there is anything else then let me know.

Henry,

Sorry I missed one of your early questions. I was not able to find any aperture stop down at various points throughout the magnification range. It was a bit hurried so I will give it another try tomorrow.

Steve,

Sorry, I posted at the same time as you.

No, they do not have the "click-stop" rotation collar like the Pentax. It is entirely free moving so you can set it at any point in the rotation.

Thanks for the compliment on the flowers. I was surprised myself. I wonder what I could do with it if I had some time and really tinkered with the setup and/or the image. I chose that subject in particular because of the color of the flowers. That vividness in purples, blues and reds is what really shows the difference in contrast for my eyes. I am still not able to really detect any color fringing on typical objects. If we get an overcast day without raing then I will put the scopes on the mountain outline. That always shows CA for moderately to poorly corrected optics.

Thanks Frank for your reply. I should of just said if it rotated. It would be better to adj. any way you wanted than the click stop in my opinion.
Regards,Steve

Frank..The photos got me even more interested..There is not false color that I can detect ,even in the high contrast areas.....maybe a higher power,Like a 14mm WA, will manage a bit better the prism issue...there are a bunch of good eyepieces,not too expensive,like the Baader Hyperion 13mm,that i bet perform great in that scope...Pentax XL series have a bit less wider field than the XW,and they should be not too expensive to find used these days..
About the Flouorite versus FPL-53 or any other ED glass..I read another post of yours mentioning the Malheur Scope(forgot the maker),and the use of pure Fluorite there..
One of the Things that make Fluorite scopes so expensive(besides the price of the Material itself) Is the Difficulty to work with Fluorite .Pure Fluorite Cristal is more fragile,and to grind a lens out of Fluorite ,apparently you need more time ,attention ,and costly techniques,...So getting a Fluorite Lens in your Objective can be seen as a statement of Quality control in itself..

Manuel,

You are thinking along the same line of thought as I. I have decided to sell the Pentax 65 with the XW 20 mm eyepiece. That means I need another 19-21 mm eyepiece with a field of view somewhere between 60-65 degrees. I am considering the Baader Hyperion, the Orion "Edge On" Flat-field and possibly one of my previous purchases the Meade 5000 series Plossl. I prefer the lower powered eyepieces for the wider field of view and brighter image.

I would also consider any other suggestions along this line that would fit my specific requirements. I would like an eyepiece that is similar in quality/optical characteristics to the factory supplied zoom currently on the scope.

Does Celestron make any highly regarded, and suitable, 1.25 inch eyepieces?

Would another ED/FL style eyepiece be a good choice?

...and on that line of thinking...what are the chances that the zoom incorporates some type of ED/FL glass in its design? Would it not be a fair assumption considering how low the color fringing levels are in the image already?

Just thinking out loud. Thanks.

FrankD said:

Henry,

Sorry I missed one of your early questions. I was not able to find any aperture stop down at various points throughout the magnification range. It was a bit hurried so I will give it another try tomorrow.

Click to expand...

Frank,

My question was about focusing distance, not magnification. I wouldn't expect magnification to matter, but a design like this one may show a stopped down aperture at close focus.

On another subject, you could use digiscoped images like the ones you posted to demonstrate the difference in color correction between the Celestrons and the Pentax and Promaster. You would need to use the same high contrast black and white target in sunlight for all scopes and, of course, use the same high magnification for all scopes. CA is most visible at the edge of a bright white object surrounded by black. For the comparison images to be useful the magnification needs to be high enough to show the CA. If the magnification is too low the photos look good, but we can't tell anything about them. Even mediocre scopes can produce nice looking images if the magnification is low enough. You can be sure that the Celestrons have some CA, although it may be less than the Pentax or Promaster. It's just not possible to make a completely color free scope with an f/6 doublet, even using Fluorite or an equivalent glass. True APO's show essentially no color even at 200x, not just 60x. Spotting scopes have it easy, they only need to look color free at relatively low magnifications.

Digiscoping is not my thing, but I know another pitfall is using a camera with a very small aperture which is the case with most point and shoots. The aperture of the camera must be larger than the exit pupil of the scope or the scope aperture will be stopped down by the camera and that will give a false impression of the scope's CA correction. That's another reason for using high magnification to reduce the size of the scope exit pupil.

On another subject, I wouldn't assume that the zoom eyepiece uses ED glass. ED is occasionally used in some eyepiece designs as an element in a negative field group that acts like a Barlow, but not always. Normally there isn't much longitudinal CA in eyepieces.


Henry

Henry,

I just checked. The aperture is not stopped down at the closest focusing distance.

As for doing a color bias/CA comparison between scopes I will see what I can do. I will need to find a contrasting black and white target...maybe something like the checkerboard you utilize.

I do agree that there must be some CA in the scope for the very reasons you mentioned. I just don't see it at normal magnification settings. The problem I am concerned with in using digiscoping at higher magnifications as a method to truly illustrate it is that I cannot be sure what CA is coming from the camera and what is coming from the scope. At least in the picture provided I can see that at the lower magnifications CA is absent to the point where I am satisfied with the color and apparent sharpness of the image. I could not always say that about some of the eyepieces I utilized in the Pentax even at lower magnifications.

I will do what I can though and post when able. We have a camping trip starting tomorrow so my time will be limited.

As for the eyepiece glass discussion....true. I was just curious if there might be something to it. My reasoning for this was fairly simple. I swapped the XW 20 and the Celestron zoom back and forth between scopes. When the Celestron was with the Celestron I noted the almost "blue-green" color bias mentioned earlier. When the Pentax was with the Pentax I noted a fairly neutral "bias" to maybe a very slightly warm tone...at least in comparison to the Celestron. When I swapped eyepieces I thought I was going to see either:

a) no difference in the color bias or...

b) a complete reversal of the color biases.

Neither was the case. What I noticed was that the color biases almost seemed to blend. The blue/green was still blue green but not as noticeably so. The neutral/warm bias was still there as well but, again, not as noticeably so. Was this observation because of the different glass types utilized or was it because of the specific coatings utilized on the glass...or maybe both?

Still, I find that I like the blue/green 'cold' image representation and wondered if this was the result of the "FL" glass objective and possibly the composition of the eyepiece design/coatings, etc...? It reminds me of the Zeiss FL's image representation hence my earlier comment about the use of an ED/FL glass in the eyepiece.

Color bias is caused almost entirely by coatings affecting the light transmission curve. Only rarely is a glass type a significant contributer, as in the notorious yellow tint of the glass used for a single element in some Russian binocular eyepieces. Scope bodies and eyepieces may have different transmission curves so that when they're combined the result is a blend of the two curves. Color bias is really a separate subject from chromatic aberration. CA has very little effect on color tint unless it's very bad, bad enough to take blue and red very far out of focus compared to yellow and green. Longitudinal CA will show itself as a purple (or possibly red) color fringe at the edge of high contrast objects, not as a color bias.

I wouldn't worry about the axial CA of the camera, or to be sure just take a photo of the CA target with the camera alone, close enough to be the same apparent size as when photographed through the scopes. If the camera had a lot of longitudinal CA we would see it in the images you already posted. I think it's good enough to just leave the camera at 2X zoom with each scope and carefully center the CA target in the scope and camera fields. You can be pretty sure that the longitudinal CA of the scopes at high magnification will be much worse than the camera. If not, they will all look the same.

Once again, no hurry. Have fun on your camping trip.

Henry

I copied this off B&H site:

"For their flagship Regals, Celestron chose to only produce angled scopes. Angled scopes are much easier to share amongst a group of observers and are generally regarded as giving a more relaxed, comfortable observing position unless you're elevated more than 45° above a subject. It takes some experience to quickly locate subjects."

jgraider said:

FrankD, thanks for the excellent review. Is it angled or straight? Are both available? Thanks.

Click to expand...

Frank,I have been tweaking with digiscoping,and DSLR photography using a long lens lately..,I have found that CA in the image can be lowered if the White balance is right..Usually I make the camera take a sample and Custom adjust white balance to every light situation..This has helped me in a number of situations to reduce CA that was caused by the lens,or "seen"by the sensor.
I use a canon A590IS,and it has a feature that allows you to use a one touch button to adjust WB to custom without enter menus,,It works great in that regard,because is easy to "fool"the sensor and make it "ignore "CA that was present in a previous picture by customizing WB often...I had Similar results when using my Pentax K10D ,..rather than setting White balance to "AUTO",I would customize White balance ,making the camera take a reading ,even when SLIGHt changing light or background.This usually has to be done pointing the camera towards a white background,but it worked well pointing the camera to most natural light settings(sometimes I will get a weird reading,but then i will just readjust ,until got the right color)..This worked well with my Vixen Geoma ED(fpl-53),and the Nikon ED50

About the use of FL,ED,"Exotic Glass"(AKA "Rare Earth") or other special type of glass in the design of the Eyepieces,I would not be surprised..Vixen uses Lanthanum crown(a type of low dispersion Glass,that has been mentioned as perhaps being used also in the eyepieces of the Chinese ED binos) in the lenses of their famous LV Zoom.Probably Celestron is using something similar..We know that most manufacturers take advantage of the same designs when possible...

Manuel,

Thank you for the suggestions on the white balance adjustment. I will try it this week and see what happens. My camera will allow me to make these adjustments fairly easily as well.

As for the glass use....again, thanks. I am going to keep an eye out for some moderately wide-field 19-21 mm eyepieces. I am tempted by one inexpensive ED fixed power eyepiece but the field of view is around 55 degrees. I believe I am getting that, or close to that, already with the factory supplied zoom. I have a Baader Hyperion 21 mm on order and should be able to comment on it with the scope by the end of the week.

As Henry suggested ,The problem with the edge of the Prism maybe a combination of wide field and low/moderate power...If the Wide field 20mm eyepieces still showing this edge,maybe a 14mm eyepiece,granting around 30X ,helps with this problem...It would still be plenty bright and It will give a bit more resolution...

How come it is so heavy? It is 65 mm but made from some special material? I am really close to order it, hope you give positive news


And.. wow at the warranty.

The NO FAULT provision of this warranty means that regardless of how the Scope may have been damaged or rendered unusable (fully or partially) by the Owner of the binocular, Celestron will repair or replace the binocular without any questions being asked

And at 61oz, do I need a stronger tripod and head then usual?