Sony V1 for digiscoping (1 Viewer)

I used my CP4500 for digiscoping, but I got tired of waiting for it to focus. I lost some good shots as a result. A week ago I received my Sony V1. It focuses very fast, nice. However, it only works with the Scoptronix Maxview 40mm eyepiece without vignetting. I've tried it on both my Swarovskis and the Leica Apo 62. Images are very good, fast focus, no vignetting, but focal length is quite low. The Maxpower device installed into the Maxview turns it into a 25mm eyepiece. Not bad. Maximal focal length obtainable at maximal zoom of the camera + SW 80 HD+ Maxview + Maxpower ~ 2200 mm. For most of the jobs it's sufficient, but I was used to a 6000mm+ focal lenght with the CP4500. A partial solution.

yossi said:

Maximal focal length obtainable at maximal zoom of the camera + SW 80 HD+ Maxview + Maxpower ~ 2200 mm. For most of the jobs it's sufficient, but I was used to a 6000mm+ focal lenght with the CP4500. A partial solution.

Click to expand...

Actually, you should get around 2500mm equivalency (18.4X * 136mm).

It seems like the Sony V1 simply requires more eye relief from the eyepiece. I think it is going to be hard to find an eyepiece less than 25mm in focal length with eye relief near the 29mm or so that the Maxview delivers. And you would need something along that line to do "better"

OTOH, 6000mm+ focal lengths far exceed the theoretical resolving capability of an 80mm objective combined with your camera. And we know that digiscoping rigs perform below what is theoretically possible.

Images at settings like 6000mm (40X eyepiece zoom and 31mm camera lens zoom) must be pretty soft and would require siginificant down-rezzing to look decent. Your scope camera combo will pretty much run out of "theoretical" resolving capability at around 30X scope power and full camera zoom (around 4000mm). So I don't think you are missing out on much. In fact, an equivalent focal length much over 4000 is the optical equivalent of using "digital zoom". It results in a bigger image but there is little or no additional detail revealed.

I wouldn't be surprised at all if you find that shots at "2500mm" actually deliver a similar level of detail as your shots at "6000mm".

Forgetting any of the theoretical stuff for a moment, as a practical matter, I find that anything over 3000mm equivalence with my CP5000 and ATS80HD is pointless. So I think your are doing pretty well with your combination. You are probably only missing out on 500mm or so of really useful range - but you are getting better focusing in return.

Thanks for the reply. Can you explain please how do you calculate the maximal resolving power of an objective? I got quite confusing results in this matter. Using the Pentax XL-7 eyepiece on my 80mm Swarovski and the CP4500 at full zoom (some 9800mm) I was able to read the engraving on a bolt on a roof some 80 meters away.
Here's the sample.

http://www.kramery.com/digitalphoto/gallery/Test/SW80_PTX7.jpg

yossi said:

Thanks for the reply. Can you explain please how do you calculate the maximal resolving power of an objective? I got quite confusing results in this matter. Using the Pentax XL-7 eyepiece on my 80mm Swarovski and the CP4500 at full zoom (some 9800mm) I was able to read the engraving on a bolt on a roof some 80 meters away.
Here's the sample.
http://www.kramery.com/digitalphoto/gallery/Test/SW80_PTX7.jpg

Click to expand...

I used the online digiscoping calculator I put together late last year.

http://www.jayandwanda.com/digiscope/digiscope_calc.html

It is based on principle that at best, optics are limited by the diffraction created by their apertures. My calculator simply determines the maximum lp/mm (line pairs per millimeter) that a digiscoping rig can resolve given its effective f-number.

Rayleigh limit (line pairs per mm) = 1/(1.22*N *W )
where "N" is the "Effective f-number" and "W" is the wavelength of green light (0.0005mm is used).

BTW, this is why few digicams let their cameras use f-numbers much higher than f8. On the CP4500, it is 10.3. The effective f-number of your 9800mm equivalent combo is about f25.

The calculator also calculates (in two ways) how many line pairs a particular CCD can resolve. If the CCD can resolve more line pairs than the scope/eyepiece/camera combination, then it is "wasted" magnification. As a practical matter, this usually happens before the theoretical limit is reached because even if the individual optics are "diffraction limited", the combination almost surely is not that good.

(BTW, if you put a scope magnification of "1" in my calculator - so that you are calculating for the camera only - and set the camera f-number to 10.3, you will see that the CCD's maximum resolution and the optics best resolution are nearly a perfect match ( 159.16 lp/mm vs. 158.98mm). I suspect this close match is not entirely coincidence.)

You'll have to fill me in a bit more on your sample image. My assumption is that it has been resized down from the original.

Calculations such as these are mostly useful to help establish guidelines. I suggest you take multiple test images at half that magnification and see if any more detail is revealed. One of the beauties of digital is that tests are cheap and feedback info is quick.

Cheers -

Yossi,

Does the V1 with Swarovski or Leica produce vignette-free images with all settings of the optical zoom or do you have to use the 'Smart zoom' setting?

Adey

Hi Adey,

When I used the Maxview eyepiece for the Leica* or for the Swarovski, I was able to zoom without vignetting from about 15mm to 28mm - approximately from mid zoom level to maximal tele. At 7mm - fully wide - I've obtained a nice circle in the middle of the frame. I did not use the "smart zoom" which is just a digital zoom I guess, as I shot at full 5 MP resolution where "smart zoom" is unavailable.

Here's a picture of an alleycat at about 10 meters away from the camera, taken with the V1+Swarovski STS 65 HD + Maxview + Maxpower , out of the camera, no processing. Warning - full size image!

* The Swarovski is better in this case. The Leica is clean from vignetting only at almost full zoom setting.

http://www.kramery.com/digitalphoto/gallery/Test/DSC00299.JPG

Yossi

Thanks, Yossi. Excellent shot!

This camera looks a viable alternative to the 4500 for digiscoping use, especially for those of us with a stock of Memory Sticks rather than CF cards.

Adey

Test results

Hi Jay,

I took this morning one shot as a reference of my "target", as I found that I have no reference picture without scopes. The target is the dish antenna and its supporting pole on my neighbor's roof. I'm attaching an image made of three 1:1 crops, not resized. The left image was taken this morning, CP4500 only, set at about mid-zoom ~ 75mm. The center image was taken in the past with the SW80+7mm Pentax eyepiece+CP4500 at fully zoomed OUT position (38mm equivalent - no vignetting!), resulting in approximately 2500mm focal length. The right image was taken at almost full zoom in (~130mm) resulting in approximately 8542mm focal length. Full zoom in (~152mm) of the camera was a little softer. The right image is a bit soft, but IMHO still usable (for whoever loves bolts and antenna poles...)

Here it is. Warning: large image.

http://www.kramery.com/digitalphoto/gallery/Test2/SW80_PTX7_2.jpg


And BTW, in order to fit the Pentax eyepiece to the Swarovski, a few millimeters should be cut off from the bottom of the eyepiece (crazy). I gave it to my mechanic to do it and I was praying that he will not harm the bottom element. Prayers help...

The price of the V1 seems to be falling like a stone in the UK - is a V2 on the way? (perhaps with Sony's new four-colour CCD filter?)

Maybe I paid too much (~$600 at B&H including a 256MB MS PRO card) but it's a cute camera. Yes, I've heard rumours about several new Sony cameras showing at the PMA show in two weeks time. It will be very bad if they'll make the camera with a small 8 MP sensor as noise will be terrible. And wait for the news from Nikon, very shortly, on a similar matter.
I don't believe they'll name it V2 and still sell it in the UK...

I very nearly typed the V1 falling ON the UK - Freudian slip or poor sense of humour!

Hopefully they'll keep the 8Mp sensor for the larger cameras like the F828 - I'll be looking out for a test report on this camera to see if the 4 colour filter is any better

yossi said:

Hi Jay,
The center image was taken in the past with the SW80+7mm Pentax eyepiece+CP4500 at fully zoomed OUT position (38mm equivalent - no vignetting!), resulting in approximately 2500mm focal length. The right image was taken at almost full zoom in (~130mm) resulting in approximately 8542mm focal length. Full zoom in (~152mm) of the camera was a little softer. The right image is a bit soft, but IMHO still usable (for whoever loves bolts and antenna poles...)

Click to expand...

First of all, let me say that the Pentax eyepiece is performing very well for you.

If you look at the finest detail in your "8500mm" shot, you can see that all the edges are soft. If you magnify the image in Photoshop you can see that edges span many pixels.

The theoretical limit of that scope and camera combination is about 4000mm. I think your scope, eyepiece and camera are probably operating pretty close to that limit. Here is my suggested test.

Shoot your target at 4000mm (12.5mm on the camera). It would be nice if you could shoot at the same settings, but also add in 2X of digital camera zoom but I don't think the camera allows that. So instead, switch to TIFF and take another shot at 4000mm. Now zoom out to 8500mm and take a third shot. Once you have the images in the computer, resize the TIFF image by 2.125X in Photoshop or another good image processing program. I suspect you will see very similar levels of detail. I did something similar with your 2500mm shot, but the magnifying the JPEG artifacting (the image was twice compressed and the second time looked to be compressed fairly significantly - 8x8 pixel block patterns were apparent).

The one advantage of the optical "overmagnification" is that it will have less noise than digital overmagnification. And if that is what you are after, then such zoom focal lengths can offer a slight advantage.

Getting back to the original topic - your V1 - it is true that you aren't getting the most magnification possible. You should keep seeing aditional detail up to around 3500mm focal length with that camera (less overall focal length than the CP4500 due to the denser array of sensor sites). Unfortunately, I don't konw of an eyepiece that will get you there. Though you might try a conventional 2X astronomical barlow which will get you to around 3100mm equivalence.

Thanks for your comments. The 8000mm image is indeed soft, but I was amazed that I didn't get a huge blur. The nice thing about the Pentax eyepieces (I have the 21mm version too) is that even at fully WA there's no vignetting, allowing full range zoom and flexibility. The barlow idea is great, and I'll try to get one for experimentaion. I never played with a barlow before, and I hope it will not degrade the image too much. I'm doing quite a lot of digiscoping using my D100 camera, and with both the Swarovki and the Leica I got easily over 2000mm, which is the upper practical limit due to the mirror induced vibration. There's no mirror lockup in the D100, just a short delay between the mirror going up and the shutter opening.
Digiscoping is fascinating, but there's no real-time action, like panning and following a bird, things I do easily with the D100 and the 500mm lens with a X1.4 or a X2 TC.

Here's a nice picture I took this evening with the V1+Swarovski

http://www.kramery.com/digitalphoto/gallery/Test2/DSC00399f.jpg

yossi said:

Digiscoping is fascinating, but there's no real-time action, like panning and following a bird, things I do easily with the D100 and the 500mm lens with a X1.4 or a X2 TC.

Here's a nice picture I took this evening with the V1+Swarovski

Click to expand...

A good peep sight can help with tracking birds. I use a Daisy LED sight designed for air pistols I think. It really helps with getting the scope quickly on the birds that don't like to sit still. It is still quite a challenge and requires a lot of patience. But it does help.

OK - here is my offtopic moon shot:
http://www.jayandwanda.com/astro/moon/

Here is the Daisy LED sight mounted to the Swarovski "peep sight"
This is not as stable as I'd like, but it does work.
http://www.jayandwanda.com/swaro/DaisySight.jpg

And this gives some idea of how the sight works. It "projects" a bright red spot onto a piece of transparent plastic on the sight. Head and eye position is not critical for accurate aiming.
http://www.jayandwanda.com/digiscope/sight.jpg

Excellent moon shot, done with the CP5000 I guess. Is the CP5000 allowing enough magnification? how is the vignetting?
I was suffering from the focussing speed of the CP4500, which the V1 cures nicely. How is the CP5000 in this respect?

yossi said:

Excellent moon shot, done with the CP5000 I guess. Is the CP5000 allowing enough magnification? hoe is the vignetting?
I was suffering from the focussing speed of the CP4500, which the V1 cures nicely. How is the CP5000 in this respect?

Click to expand...

Thanks, and yes that was taken with the CP5000 (and an unconventional "scope").

The CP5000 allows plenty of magnification if you also use the Swarovski 20-60x zoom. You simply rely on the zoom lens for the lack of reach that the 28-85mm equivalent lens on the CP5000 provides.

With the Swarovski 20-60x and their DCA adapter, and the eyepiece at 20X, I will zoom wide with the camera lens to just under 14mm. This is a nice low power view of around 1100mm equivalency. This is where vignetting begins. Depending on the shot, I'll sometimes choose to live with a small amount of dark corners. The camera will provide unvignetted views at any focal length beyond 14mm. Zooming out the camera to 21.4mm gives me around 1700mm of focal length equivalency.

If I want more reach, I simply start zooming the eyepiece. Usually I zoom directly to 30X. The eye relief of the 20-60x eyepiece changes as it is zoomed and the area between 20x and 30x seems like "no man's land" and produces significant "soft" vignetting. This all clears up at around 30X. Image quality seems to hold up to around the 35X setting on the eyepiece before softness begins to be more than I like. This gets me out to around 3000mm equivalency.

In good light the CP5000 focuses just fine for me. But it is no better than the CP995. I live and digiscope mostly around Phoenix, AZ and we usually have bright sun. I had more difficulty when I visited the very overcast Seattle, WA over Thanksgiving. I find that the CP5000 images very similarly to the CP995. It just has more pixels.

Right now, the C-5060 looks like the best bet for 5MP digiscoping if people want to use their standard scope eyepieces. Its 4X lens with a 28-116mm equivalency gives it a bit of an edge on the CP5000. It will take some time to see for sure, but the initial results from the fellows in Malaysia seem very positive. My only real complaint is that I don't like the trend toward packing more pixels on the same little 8.93mm diagonal CCD. This is not good for low noise images. But it is good for keeping the camera prices down.

Thanks for the answers. A couple more questions please:
1. What in your opinion is the maximal focal length - while still outputting reasonable quality, of the following scopes: SW80HD, SW65HD, Leica Apo 62 and Nikon FSIIIED?
2. Can you elaborate more on the Olympus 5060? I saw some pictures (not digiscoped) out of this camera, and they are very good - sharpness is great and the noise level at ISO64, despite the small sensor, is quite low.

Thanks

Yossi

In another thread on the Olympus C-5060 I referred to a test report in the UK photo magazine 'Amateur Photographer'

The tester had a few concerns about the rendition of fine detail and also slightly out-of-focus areas of plain tone which looked a bit 'water-colour'-like.

Also, there was a certain amount of colour fringing, probably no more than any other similar types of camera.

On the plus side, the noise levels were very good. At all ISO speeds he inferred that it was better than expected.

Even illumination over the whole frame at the wide-angle end was also noted

Adey Baker said:

The price of the V1 seems to be falling like a stone in the UK - is a V2 on the way? (perhaps with Sony's new four-colour CCD filter?)

Click to expand...

The Sony W1 may be either a replacement or complimentary camera to the V1 - either way, the more modest 3x zom lens with a maximum aperture of F5.2 at the long end could be better for digiscoping with a scope's usual eyepiece.

Daisy LED sight

Jay where did you find the Daisy LED sight? At what distances can you use it at?

Very nice pictures.


Carl

Jay Turberville said:

A good peep sight can help with tracking birds. I use a Daisy LED sight designed for air pistols I think. It really helps with getting the scope quickly on the birds that don't like to sit still. It is still quite a challenge and requires a lot of patience. But it does help.

OK - here is my offtopic moon shot:
http://www.jayandwanda.com/astro/moon/

Here is the Daisy LED sight mounted to the Swarovski "peep sight"
This is not as stable as I'd like, but it does work.
http://www.jayandwanda.com/swaro/DaisySight.jpg

And this gives some idea of how the sight works. It "projects" a bright red spot onto a piece of transparent plastic on the sight. Head and eye position is not critical for accurate aiming.
http://www.jayandwanda.com/digiscope/sight.jpg

Click to expand...