An interesting comparison...

[bladekeeper]

Back in September, Explore Scientific was running a sale on eyepieces and accessories. They had their 2× focal extenders reduced in price. I whupped on down to the ES store on 30 September (last day of the sale) and slapped some cash down for one. I figured that one of these rascals might squeeze another drop or two of juice from my lunar imaging efforts.

Unfortunately, after paying for one of these, we determined that ES may just be out of stock despite what their inventory indicated. Heck, we even went back to the warehouse and dug around in boxes and did not find one. They were indeed out of stock.

My options were to get my money refunded and buy one later when they came back in stock, or wait it out. I elected to wait as it was the $60.00 cheaper option.

I checked their website periodically and it continued to tell me these were sold out. I inquired of my friend that works there as to when these could be expected and learned a lot about manufacturing processes and the overall shipping attitude with the folks in China that make these things.

Lo and behold though, this past Thursday the ES website was showing these back in stock. I sent a FB Messenger note to my buddy at ES today asking if I could swing by and pick up my goods and was told to come on down. So down I went and got my new toy.

Since it was clear this evening, I got to try out this 1.25" 2× focal extender with my Stellarvue SV102T. I also brought out my $40.00 1.25" 2× Synta barlow that I normally use. I ran off a 3-panel mosaic with each of these devices in front of the cam.

Can you tell which is which?

20200104 18_39_18_g4_ap91 M1_1_stitch by Bryan Gabbard, on Flickr

20200104 18_44_23_g4_ap124 M2_1_stitch by Bryan Gabbard, on Flickr

[Lady Fraktor]

The bottom one is the ES

[Piet Le Roux]

They are both beautiful but the bottom one it a bit more crispy, so yes that should be the ES

[Graeme1858]

The bottom one is the ES

Seconded!

[Lowjiber]

I put them side-by-side in PS to help comparison with these old eyes. The second one is sharper IMHO.

Clear, Dark Skies

[Mac]

The bottom one is the ES. It's sharper and lacks the slight CA of the top one.

[Thefatkitty]

Hey buddy Good to hear you're getting some sky time in... Great story; good for you on holding out. A man after my own heart.

They are both great images, for sure. However, the bottom one just looks a little crisper and not the slightest hint of CA. I'd be betting the bottom image is with the ES.

I replied to this before I read any of the responses, and now in doing so, it seems I'm with the majority. Reminds me of the Black Sabbath concert I saw in '82... Mob Rules!

Well done on both counts!

[UlteriorModem]

I don't really know. I do know the bottom one is a bit sharper. If that was due to the instrument, seeing, or processing who knows

To me there pretty comparable. Nice job on the mosaics btw. Seamless!

[SKEtrip]

Wonderful images, Bryan.
Just to be contrary, I'll say the second one is the Synta

[j.gardavsky]

There is a time lapse between the both mosaics.
The second mosaic shows some higher contrast, which may also be due to the later time at night and better seeing or whatever, when the imaging has been made.

Otherwise, I like the both,
JG

PS edit: The both mosaics show a blue fringe residual at north, and a yellow/green at south, something like mismatch in the optics axes.
Maybe, I am the only one who can see it.

[Refractordude]

The bottom/second image is much more contrastry.

[Lady Fraktor]

There is a time lapse between the both mosaics.
The second mosaic shows some higher contrast, which may also be due to the later time at night and better seeing or whatever, when the imaging has been made.

Otherwise, I like the both,
JG

PS edit: The both mosaics show a blue fringe residual at north, and a yellow/green at south, something like mismatch in the optics axes.
Maybe, I am the only one who can see it.

I based my guess on these factors as well as the slight difference of surface colour.

[bladekeeper]

Awesome! Thanks so much for playing along, friends! I sincerely appreciate your objective evaluations of each image. I was afraid I might be a tad biased since I was aware of which was which.

The first one may be a tad softer due to a slight focus issue on my part. I am going to try this evening using both again to see if I achieve similar results.

As for which is which, the top mosaic was done using the ES 2× focal extender while the bottom mosaic was done with the 2× Synta barlow.

I must note that the ES did put up a brighter image. I had to notch up the exposure a hair with the Synta.

So far, I'm not seeing enough of a difference to justify the expense of the ES. I am hoping to repeat this experiment (sans asking for your guesses) a few more times to see how consistent the results are.

Thanks for playing along! Very much appreciated!

[UlteriorModem]

I must note that the ES did put up a brighter image. I had to notch up the exposure a hair with the Synta.

So there is your difference. The ES is a few milliseconds faster

[Thefatkitty]

So much for the Mob mentality... That's interesting, I'm thinking with Tom, slightly faster or maybe just better glass?

Thanks for that little "test"; I find it interesting and helpful to boot. Reminds me of when I bought my iOptron dielectric diagonal. I was somewhat surprised when I discovered my old Celestron/Vixen Star diagonal with it's prism put up a brighter and larger view. So much for advertising...

[Sinerjee]

Maybe the extended exposure of the Synta is what threw everyone off?
Could you maybe get a shot with the same settings which should give a clearer comparison between the two?

[bladekeeper]

Maybe the extended exposure of the Synta is what threw everyone off?
Could you maybe get a shot with the same settings which should give a clearer comparison between the two?

Yeah, I will definitely do that at the next opportunity.

Alas, this evening, I again bumped the exposure on the Synta. Granted, we are talking 5/10ths of a millisecond here, not much of a bump, but enough to make a difference...thread forth-coming.

I think I nailed focus with the ES much better this evening. I think.

[Sinerjee]

Maybe the extended exposure of the Synta is what threw everyone off?
Could you maybe get a shot with the same settings which should give a clearer comparison between the two?

Yeah, I will definitely do that at the next opportunity.

Alas, this evening, I again bumped the exposure on the Synta. Granted, we are talking 5/10ths of a millisecond here, not much of a bump, but enough to make a difference...thread forth-coming.

I think I nailed focus with the ES much better this evening. I think.

Thanks for showing the comparison though. I have a Celestron 2x Barlow at the moment. I presume it's similar to the Synta one you describe.
I'm considering getting the Televue 2x Barlow though. At $189AUD it would be quite an investment for me so to not see much in the way of differences here makes me think it might not be worth it.

[bladekeeper]

Maybe the extended exposure of the Synta is what threw everyone off?
Could you maybe get a shot with the same settings which should give a clearer comparison between the two?

Yeah, I will definitely do that at the next opportunity.

Alas, this evening, I again bumped the exposure on the Synta. Granted, we are talking 5/10ths of a millisecond here, not much of a bump, but enough to make a difference...thread forth-coming.

I think I nailed focus with the ES much better this evening. I think.

Thanks for showing the comparison though. I have a Celestron 2x Barlow at the moment. I presume it's similar to the Synta one you describe.
I'm considering getting the Televue 2x Barlow though. At $189AUD it would be quite an investment for me so to not see much in the way of differences here makes me think it might not be worth it.

You likely have the same barlow as I do.

Also, there can be differences in quality from barlow to barlow, especially with the cheaper options (less consistency in quality). It may be that I got lucky and got a really good one. I've never used a Televue, so it may also be a case of "ignorance is bliss" on my part.

I have read favorable comments on the Televue, though.