Phenix Optics Co 127mm (5") Rich Field Achromatic Refractor

As these scopes are imported for us to be sold through our AstroShop I guess it's a bit like reviewing your own play!

The scope we chose as our sample was picked out as it had obviously had a very  rough trip and the outer packaging had burst open. Not a very scientific way of choosing I agree, but the assumption was that if this scope was still in one piece there was a good chance that the others had fared better still... as a footnote here, we check each of them for functionality prior to despatch.

As always with these reviews, whilst it may be presumed that our sample is representative there is no guarantee of this. However we have seen a fair few of these instruments, and whilst our 'checks' aren't as thorough as the tests carried out during our reviews they do add a degree of confidence.

Review - One of the first things that strikes you about these scopes is the weight, complete in the flight case it weighs in at around 32kg so care needs to be taken when handling. However half the weight turns out to be the flight case itself... the scope and the mount are far more manageable with a total weight of just under 16kg.

As mentioned earlier the OTA and mount come neatly packed in a solid flight case, which provides safe storage when the scope is not in use.

Descriptively the scope itself is pretty much the same as its longer cousin which we have reviewed elsewhere. The tube assembly is well constructed - giving an overall impression of a solid and quite imposing instrument.

Like the D127F1200 the OTA is nicely finished in white, which I liked and a silver/grey Hammerite that in my opinion makes it look a bit dated. The mount, as can be seen in the picture is also finished in a silver/grey Hammerite.

As far as the OTA was concerned I found that the focuser is a little stiff for my liking, but as there is no friction adjustment this is probably an advantage. Overall the focus adjustment was reasonably smooth even if a little tight.

The OTA has a single internal baffle which seems to be positioned and sized about right... In my opinion it could do with a few more. And again like its longer cousin it could also do with some baffling in the focus tube itself.

The focuser has an integral adaptor that allows both 1.25" and 2" accessories to be used.

Moving on to the mount, the scope comes with a lighter version of equatorial mount than the D127F1200. The lack of motor drives is not so much of a problem with a rich field scope as you are generally using lower magnifications and manual tracking is therefore easier...

The mount and in particular the counterweight are just about adequate for this scope. If you wished to add heavy accessories then an additional weight would be required. That said, for a lightweight equatorial mount this provides a surprisingly solid platform and I was very pleased with this mount. We believe that motor drives are available and are looking at obtaining samples - but we have never fitted or tried them for ourselves. The mount includes a built in spirit level and polar alignment scope which is a bonus.

One slight complaint is that the latitude adjustment screw is barely long enough to adjust for our latitude and if you lived much further North this would require replacing with a longer bolt.

Performance - The mount makes a solid and perfectly usable platform for visual use and would probably be adequate for prime focus imaging, certainly with brighter objects.

There is obviously some CA (Chromatic Aberration) with this scope, that is unavoidable in an Achromatic refractor. An obvious question being; how does it compare with the longer D127F1200 version?

CA is more noticeable than with the D127F1200 and in my opinion the D127F700 will not bear as high a magnification, however that is quite subjective as some people are more tolerant of CA than others. It is also difficult to assess, as eyepieces will perform very differently on a scope operating at f/5.5 as opposed to f/9.5, so a certain amount of caution needs to be exercised...

In the end comparisons were made with our 150mm (6") SNT as having approximately the same focal ratio eyepieces should perform similarly.

At low powers CA is only really noticeable off axis, however as the power is stepped up it becomes increasingly obvious - particularly in a side by side comparison with a CA free scope. The SNT outperformed the D127F700 in most other respects too, but set against this the SNT costs over twice as much and has a larger aperture.

Being designed as a rich field scope this is where it comes into its own - but even so, at low to medium powers it also gives some nice views of the moon and planets. The Pleiades and other clusters are quite impressive in this scope and it is ideal for just browsing the sky as you would with binoculars. With a good two inch eyepiece some of the views certainly have the 'wow factor' particularly if you have never used a rich field scope before.

As with the D127F1200 my biggest complaint with this scope is that whilst the main tube is baffled the drawtube is not. Again the inside of the drawtube is not as flat a black as it could be. This tends to be more of a problem when this scope is used as a terrestrial scope.

Finally, as is often the case, the finder isn't great but it will at least allow you to find some of the brighter objects. We tended to use the scope at low power without bothering to fit the finder.

In summary - I was very pleased with the mount which is as good as I have seen with any scope in this price range.

The eyepieces and diagonal are of reasonable quality and perform well, whilst the OTA is  well constructed and nicely finished. Overall I believe the scope represents good value for money and a bit of work on the drawtube would bring it up a level in terms of overall performance.

Other SVO sites

Emma's Candle Emporium
See View Observatory AstroShop
 The Haunted Natterbox Discussion Forums