ASTROPHOTOGRAPHY WITH THE NIKON D70 DIGITAL SLR CAMERA Last updated: 22 June 2005

Eyepiece Projection Astrophotography
Using the Scopetronix MaxView DSLR II and T-Ring for the D70 I did some eyepiece projection astrophotography through my LXD55-8"SC.

All of the following test photographs were taken using an ISO 200 setting and the wireless remote to trip the shutter for the exposure. Exposure length, eyepiece focal length, and whether TeleNegative Lens was used is noted for each photograph. Image size was set at 1504 × 1000 with the quality set at JPEG Fine. Noise Reduction (NR) was enabled. Images have been edited (levels and sharpening, as needed), their image size reduced and JPEG compression applied. The "hat trick" method was not used for any exposures so vibrations due to DSLR mirror flipping may be evident.

Moon

1.25" 26mm eyepiece, 1/2 second

1.25" 26mm eyepiece, TeleNegative Lens, 1/2 second

Jupiter

1.25" 26mm eyepiece, 1/2 second

1.25" 26mm eyepiece, TeleNegative Lens, 1 second

Four things are evident from the above:

1. Use of a higher ISO setting and/or the "hat trick" method of covering the telescope aperture, opening the camera shutter, flipping the cover out of the light path for the duration of the exposure and the back, and then close the shutter, would help. Otherwise vibration due to the mirror flipping could be a problem although it is less evident with the LXD55 than with the ETX models.

2. Precise focusing is difficult, especially at high magnification. Using a "Hartmann Mask" would help.

3. Use of a higher resolution (the D70 can go up to 3008 × 2000) will allow cropping to increase the effective image scale.

4. For planetary photography the use of short exposures and stacking would help tremendously. I'll be working on that soon.

20 May 2005
Finally had a chance to do some Moon tests with my 2" Tele Vue 35mm Panoptic eyepiece on my LXD55-8"SC. I set the camera to ISO 1600 for these.

2" 35mm eyepiece, 1/250th second

2" 35mm eyepiece, 1/250th second

2" 35mm eyepiece, 1/250th second

2" 35mm eyepiece plus Telenegative Lens, 1/125th second

2" 35mm eyepiece plus Telenegative Lens, 1/125th second

Some adjustments were done in iPhoto 5 and sharpening in GraphicConverter. While the seeing was pretty lousy, you will notice there is no vibration due to the camera mirror motion. However, you will see some noise, especially in the last two. (I have not yet updated to the new Nikon D70 2.0 firmware.)

OK, enough of the tests. Time to move on to getting some real good shots! Of course, that is weather and schedule permitting! Stay tuned.

19 June 2005
Eyepiece projection taken with a Nikon D70 DSLR mounted to a LXD55-8"SC using a Scopetronix MaxView II DSLR Adapter and a 26mm eyepiece and the MaxView TeleNegative Lens.

Here is a single frame from a series exposed at 1/4 second at ISO 800 (size reduced 50% but otherwise unedited):

And here is the result of stacking, cropping, and editing 14 individual shots using Lynkeos 1.3 for Mac OS X.

Even though I used a Hartmann Mask to aid in focusing, the focus is still not as crisp as I expected. More work to do.

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