Nikon D610 or Nikon D7000/7100 modded?

[AdamButko]

Hey everyone,

 

I'm currently in the market for a new DSLR dedicated to AP. I have been using a Nikon D300 which is innately noisy and requires very lengthy exposures especially on my slow 8"SCT. I will eventually get a triplet APO but for the time being I'm using the SCT and focusing on a camera upgrade. My focus is DSO.

 

I borrowed my friends D7100 and it allowed me to capture more whispy detail on M42 and defined spiral arms of M81 and M51. After playing around with this camera I was fixating on getting a full frame Nikon D610 for even lower noise at higher ISO. However I have come across a lot of threads and photos of lower end cameras with the infrared filter removed, the D7000 for instance, and I was wondering if in your opinion the sacrifice in noise (getting a D7000/D7100 and removing the IR filter) is worth the hydrogen capturing capabilities. I'm not particularly interested in modding a D610.

 

I can get a D7000 for around 500$, or a D610 for 1500$. I'm not looking to save money, I'm looking for the best outcome and the most longevity. If a modded D7000/D7100 would suffice, I'm looking at getting an APO much sooner. Or if a modded D610 would blow these options out of the water, I would have to seriously contemplate that as I am not much of a 'daytime photographer' anyway.

 

Any experience with modded Nikons, or your opinion on who would win a tug of war (modded D7000/D7100 vs unmodded D610) would be greatly appreciated.

 

Cheers and clear skies,

 

Adam

[s3igell]

Assuming Celestron's 8" EdgeHD produces the same fully-illuminated light cone as its congruent 8" non-EdgeHD model (what I currently have) then my SCT would illuminate a full frame sensor.

I'm not sure this is accurate.  I get demonstrable Vignetting on my C9.25 using my Canon APS-C Crop Frame DSLRs (although it is recoverable via Flats Calibration).  I don't think that this would be possible with a Full-Frame Camera.

[AdamButko]

Well after considering your comments and much research I've decided to purchase the Nikon D5300, larger Sony sensor compared to the D300 I'm using now. I will be looking at modifying it myself in the near future, though there aren't as many available AP clips for Nikon as there are Canon.

 

I'll also be purchasing an APO much sooner than I was anticipating (yay) Stellarvue 80mm triplet. The AVX should support it fine. 

 

Thanks for all the help. If you have any comments or guidance in regards to astromodifying the D5300, I would greatly appreciate it!

[admin]

The D7000 has a sony sensor but requires a serial cable for BULB.

 

The D7100 has a Toshiba sensor and does not require a serial cable for bulb.  Sony sensors are better.

 

I do not know which sensor the D610 has.

 

If this were me I would look at the D5300 or D5500 which both have Sony sensors and both can do BULB over USB, no serial cable required.

 

Regards,

[s3igell]

The whole Goal is to Collect Photons in the Sensors, and have the Camera Sensor Pixels be Sensitive.  AND have the Product of those Sensitive Pixels NOT also be High Noise Levels.

 

ISO is NOT a Good Measure of these Goals.

With actual Chemical Film, ISO was a True Measure of the Sensitivity of the Emulsion.  With Digital Sensors, ISO is just an After-the-Fact Multiplication Routine which is more the equivalent to Gain in an Amplifier.  

DSLR Manufacturers still use ISO as a Measuring Tool because of it's longstanding Familiarity with Film Photographers, but we are now left to decide "How Much Noise is Acceptible for any Increase in Amplification".

 

The Sony Sensors have a Great Track Record of Late with Low Noise Generation and High Sensitivity.  But they have also been Faulted for some of their Built-In Noise Suppression and RAW Handling - moreso in the Sony DSLRS.

The D5300 and D5500 have 24MP Sony Sensors, a Good Choice.

 

Removal of the Photographic IR-Cut Filter, and Replacement with an AP-specific IR-Cut Filter is the Greatest Improvement possible with a DSLR.  A GREAT PORTION of the Light available in the Cosmos is Ha - and most Photographic IR-Cut Filters knock-out at least 50-70% of that Frequency.

You probably DON'T want the IR Filter simply Removed, since you state your desire for an APO Refractor.  You'll have significant Fringing and Star Bloat due to the Deeper IR Frequencies not coming to Precision Focus at the same distance as Visible and Ha Light.

 

You'll also want to think hard before going with a Full-Frame Sensor, as that requires both Longer Focal Length / Slower Focal Ratio Scopes OR Larger Focuser Bore / Larger Illuminated Circle engineering in the Scope Design - something that adds COST to an APO Refractor (and you mention a Budget).

 

Again, a D5300 with the IR-Cut Filter Mod sounds like your Best Bet.

[AdamButko]

Guyroch, I do have a DSUSB box/cable which I currently use for my D300. I can use it for the D7000 as well, I would just need a ~20$ cable so that doesn't rule out the D7000 for me. I am interested in sticking with a sony sensor though, which the nikon D610 has. In terms of the sensors, full frame @ 5.9 micrometers vs APS-C @ 3.9 micrometers, what would yield better results, a modded Nikon D5500 or a stock D610? I know it's sort of an arbitrary question but in terms of noise, nebulosity, if you can comment on this.

 

S3igell, thank you for the informative response. Would there be any benefit of choosing a D5500 over a d5300? How come not a D7000? As I mentioned, I am planning on obtaining a triplet APO eventually but for the time being I will be using the new camera with my 8" SCT. If I only remove the IR cut filter and don't replace it with an AP IR filter, I imagine I will have 'fringing and star bloat' when using the SCT as well?

 

The focal length of my 8" is +2000mm, f/10. I currently use a focal reducer than brings it down to f/6.3 and flattens the field. I assume full frame would not be an issue for the SCT but it would make for a costly APO? If that is the case then full frame is not a good commitment as the end game is an APO with a temperature controlled ccd.

 

Also, if you can comment on this, how would a modded D5300/D5500 compare to a stock D610 in terms of quality and noise? (Full frame @ 5.9 micrometers vs APS-C @ 3.9 micrometers)

 

Thank you for all the help thus far, I am slowly getting a better idea of the direction I'm heading.

 

Adam

[admin]

The D7000 has a sony sensor as well.

[astroman133]

Adam,

 

There are several issue related to choosing a good camera.

 

One of the key issues with a full frame camera is the following -- Will the telescope(s) that you are using fully-illuminate the larger sensor? You need to research this to find out the diameter of the fully-illuminated light cone for the instruments that you want to use. Otherwise you will be fighting severe vignetting that you may not have with the smaller sensor.

 

Another thing is the reputation of whomever is modifying the camera and the difficulty of getting the camera repaired once it has been modified.  I know a guy who snagged a cable and broke the USB socket on his Canon.  He brought the camera to a local shop and gave them explicit instructions that the camera had been modded and that the sensor should not be recalibrated.  The camera shop sent the camera to Canon for repair and Canon ignored the instructions.  Then Canon wanted several hundred dollars to repair the repair and the local shop said "not our fault". He was out of luck and has since abandoned Canon.

 

I have read info on Gary Honus's web site, he no longer puts Baader filters into the cameras that he modifies.  He only puts in optical quality clear glass.  How suitable is this modification for imaging with a refractor?

 

Finally, depending on your sky conditions, a camera with pixels that are relatively small may work fine with a fast refractor but be oversampled and give less than satisfying results with a long focal length SCT.

 

If only it were as easy as "can I afford it"!

[AdamButko]

Rick,

 

Assuming Celestron's 8" EdgeHD produces the same fully-illuminated light cone as its congruent 8" non-EdgeHD model (what I currently have) then my SCT would illuminate a full frame sensor.

 

I understand the IR-filter modification can be risky and I would prefer to have it done on a lower end Nikon. If I cannot find someone with a flawless reputation I would consider doing it myself. If I were to get a D610 I would heavily favor keeping it stock.

 

The seeing conditions North of Toronto are sub-par. I usually suffer with transparency which is at best around average but typically below. A larger pixel size would be more suitable for an 8" SCT, would that be a consequence of longer focal length requiring longer exposure times while a smaller pixel size is more sensitive to variations in the atmosphere?

 

I purchased this 8" SCT as my first scope roughly 7 months ago. Since then I have been very adamant towards learning AP and after many failed attempts I have successfully guided up to 3 minutes on multiple DSO's with no star trails or field rotation. The more I progress the more I realize that coma is a critical issue. The focal reducer which I use improves it but by no means eliminates it. Maybe I'm looking at this whole thing wrong... if I were to get a new camera and use it with my current SCT, I will be looking at purchasing an APO that provides a flat field instantaneously. Perhaps it would be in my best interest to purchase an 80/120mm APO with a DSLR that would compliment it? It would cost a pretty penny but if I were to get an APO that provides a flat field then I do not see myself using a slower photon collecting and coma infested SCT very often.

 

Adam

[astroman133]

Adam,

 

I bought my 8" CGEM EdgeHD in 2010 and not long after decided that I wanted to try imaging.  I almost gave up trying to learn how to do astrophotography, but decided to throw some more money at the problem.  I bought a premium 5" refractor.  The shorter focal length made a world of difference.  I never imaged with the EdgeHD after that.

 

Good luck on your journey!

[AdamButko]

Now it's a question of getting a Stellarvue 80 Triplet, a William Optics 81 GTF, WO Zenisthstar 71, WO Star 71... I think I'm ruling out ES 102 and SW ED80. Been doing lots of research on refractors today. Any opinions/recommendations? The focus is DSO, the galaxies will unfortunately be small.

[s3igell]

Guyroch, I do have a DSUSB box/cable which I currently use for my D300. I can use it for the D7000 as well, I would just need a ~20$ cable so that doesn't rule out the D7000 for me. I am interested in sticking with a sony sensor though, which the nikon D610 has. In terms of the sensors, full frame @ 5.9 micrometers vs APS-C @ 3.9 micrometers, what would yield better results, a modded Nikon D5500 or a stock D610? I know it's sort of an arbitrary question but in terms of noise, nebulosity, if you can comment on this.

Since you ask specifically about "the Nebulosity":  The IR-Cut Filter Modded D5500 will capture significantly more of the All-Important Ha Nebulosity.  Sensor Sensitivity aside, the Ha Frequency will simply be BLOCKED from the D610.  

 

In terms of Noise, the D610 will win - according to DxO data - but not by the amount expected...